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<?xml version="1.0" encoding="utf-8" ?> Part II. How do I Become a GIMP Wizard? Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Part II.
How do I Become a GIMP Wizard?
Table of Contents 5. Getting Images into GIMP 1. Image Types 2. Creating new Files 3. Opening Files 3.1. Open File 3.2. Open Location 3. 3. Open Recent 3.4. Using External Programs 3.5. File Manager 3.6. Drag and Drop 3.7. Copy and Paste 3.8. Image Browser 6. Getting Images out of GIMP 1. Files 1.1. Save / Export Images 1.2. File Formats 2. Preparing your Images for the Web 2.1. Images with an Optimal Size/Quality Ratio 2.2. Reducing the File Size Even More 2.3. Saving Images with Transparency 7. Painting with GIMP 1. The Selection 1.1. Feathering 1.2. Making a Selection Partially Transparent 2. Creating and Using Selections 2.1. Moving a Selection 2.2. Adding or subtracting selections 3. The QuickMask 3.1. Overview 3.2. Properties 4. Using QuickMask Mode 5.
Paths
5.1. Path Creation 5.2. Path Properties 5. 3. Paths and Selections 5.4. Transforming Paths 5. 5. Stroking a Path 5. 6. Paths and Text 5.7. Paths and SVG files 6. Brushes 7. Adding New Brushes 8. The GIH Dialog Box 9. Varying brush size 9.1. How to vary the height of a brush 9.2. Creating a brush quickly 10. Gradients 11. Patterns 12. Palettes 12.1. Colormap 13. Presets 14. Drawing Simple Objects 14. 1. Drawing a Straight Line 14.2. Creating a Basic Shape 8. Combining Images 1. Introduction to Layers 1.1. Layer Properties 2. Layer Modes 3. Creating New Layers 4. Layer Groups 9. Text Management 1. Text Management 2. Text Tool Box 2.1. Text Tool Box Context menu 3. Text 3.1. Embellishing Text 3.2. Adding Fonts 3.3. Font Problems 10. Enhancing Photographs 1. Working with Digital Camera Photos 1.1. Introduction 1.2. Improving Composition 1.3. Improving Colors 1.4. Adjusting Sharpness 1.5. Removing Unwanted Objects from an Image 1.6. Saving Your Results 11. Color Management with GIMP 1. Color Management in GIMP 1.1. Problems of a non Color Managed Workflow 1.2. Introduction to a Color Managed Workflow 12. Enrich my GIMP 1. Preferences Dialog 1.1. Introduction 1.2. Environment 1.3. Interface 1.4. Theme 1.5. Help System 1.6. Tool Options 1.7. Toolbox 1.8. Default Image Preferences 1.9. Default Image Grid 1.10. Image Windows 1.11. Image Window Appearance 1.12. Image Window Title and Statusbar 1.13. Display 1.14. Color Management 1.15. Input Devices 1.16. Input Controllers 1.17. Window Management 1.18. Folders 1.19. Data Folders 2. Grids and Guides 2.1. The Image Grid 2.2. Guides 3. Rendering a Grid 4. How to Set Your Tile Cache 5. Creating Shortcuts to Menu Functions 6. Customize Splash-Screen 13. Scripting 1. Plugins 1.1. Introduction 1.2. Using Plugins 1.3. Installing New Plugins 1.4. Writing Plugins 2. Using Script-Fu Scripts 2.1. Script-Fu? 2.2. Installing Script-Fus 2. 3. Do's and Don'ts 2.4. Different Kinds Of Script-Fus 2.5. Standalone Scripts 2.6. Image-Dependent Scripts 3. A Script-Fu Tutorial 3.1. Getting Acquainted With Scheme 3.2. Variables And Functions 3.3. Lists, Lists And More Lists 3.4. Your First Script-Fu Script 3. 5. Giving Our Script Some Guts 3.6. Extending The Text Box Script 3.7. Your script and its working Chapter 4. Getting Unstuck Chapter 5. Getting Images into GIMP  Report an error in Bugzilla  Bibliography Bibliography  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Bibliography Books [ APRESS00 ] Beginning GIMP: From Novice to Professional . Akkana Peck . Copyright © 2006 Apress Inc.. Apress Inc, www.apress.com. ISBN 1-59059-587-4. http://gimpbook.com/
. [ FOLEY01 ] Computer Graphics, Principles and Practice . Foley and van Dam, et al . Copyright © 1990 Addison Wesley. Addison Wesley. 2nd Ed. (Addison Wesley, 1990)
. [ GROKKING ] Grokking the Gimp . Carey Bunks . Copyright © 2000 New Riders Publishing.
New Riders Publishing, www.newriders.com
. ISBN 0-7357-0924-6.
http://gimp-savvy.com/BOOK
. Online resources [ AdobeRGB ] Adobe RGB (1998) ICC Profile .
http://www.adobe.com/digitalimag/adobergb.html
. [ AdvanceMAME ] AdvanceMAME project .
http://advancemame.sourceforge.net/
. [ APOD ] Astronomy Picture of the Day .
http://antwrp.gsfc.nasa.gov/apod/
. [ APOD01 ] Astronomy Picture of the Day (today) .
http://antwrp.gsfc.nasa.gov/apod/astropix.html
. [ APOD02 ]
Astronomy Picture of the Day - The Hubble Ultra Deep Field (2004 March
9)
.
http://antwrp.gsfc.nasa.gov/apod/ap040309.html
. [ APOD03 ]
Astronomy Picture of the Day - M51: Cosmic Whirlpool (2002 July 10)
.
http://antwrp.gsfc.nasa.gov/apod/ap020710.html
. [ APOD04 ]
Astronomy Picture of the Day - Saturn: Lord of the Rings (2002
February 15)
.
http://antwrp.gsfc.nasa.gov/apod/ap020215.html
. [ APOD05 ]
Astronomy Picture of the Day - NGC 6369: The Little Ghost Nebula (2002
November 8)
.
http://antwrp.gsfc.nasa.gov/apod/ap021108.html
. [ APOD06 ]
Astronomy Picture of the Day - Disorder in Stephan's Quintet (2000
November 13)
.
http://antwrp.gsfc.nasa.gov/apod/ap001113.html
. [ APOD07 ]
Astronomy Picture of the Day - The Sharpest View of the Sun (2002
November 14)
.
http://antwrp.gsfc.nasa.gov/apod/ap021114.html
. [ ARGYLLCMS ] Argyll Color Management System Home Page .
http://www.argyllcms.com/
. [ BABL ] babl (pixel format translation library) . http://www.gegl.org/babl
. [ BACH04 ] Face in blocks . Michael Bach . Copyright © 2004 Michael Bach.
http://www.michaelbach.de/ot/fcs_mosaic/
. [ BUDIG01 ] Golden Text .
http://www.home.unix-ag.org/simon/gimp/golden.html
. [ BUGZILLA ] Bugzilla .
http://bugzilla.gnome.org
. [ BUGZILLA-GIMP ] Bugzilla-GIMP .
http://bugzilla.gnome.org/browse.cgi?product=GIMP
. [ CAIRO ] Cairo .
http://www.cairographics.org
. [ DARWINORTS ] Darwin Ports Package Manager for OS X . http://darwinports.org
. [ ECI ] ECI (European Color Initiative) Profiles .
http://www.eci.org/eci/en/060_downloads.php
. [ FDL-TRANSLATION ]
Unofficial translation of the GNU Free Documentation License
. [ FINK ] Fink Package Manager for OS X . http://fink.sf.net
. [ FREETYPE ] Freetype 2 home page .
http://www.freetype.org/freetype2/index.html
. [ GEGL ] GEGL (Generic Graphics Library) . http://gegl.org
. [ GEORGIEV01 ] Image Reconstruction Invariant to Relighting . Todor Georgiev . Copyright © 2005 Todor Georgiev.
http://www.tgeorgiev.net/Invariant.pdf
. [ GHOSTSCRIPT ] Ghostscript project page on Sourceforge .net .
http://sourceforge.net/projects/ghostscript
. [ GIMP ] GIMP - The Gnu Image Manipulation Program . http://gimp.org
. [ GIMP-DEV ] GIMP Development .
http://developer.gimp.org
. [ GIMP-DEV-PLUGIN ] GIMP Plugin Development .
http://developer.gimp.org/plug-ins.html
. [ GIMP-DOCS ] GIMP Documentation project page .
http://docs.gimp.org
. [ GIMP-FONTS ] Fonts in GIMP 2.0 .
http://gimp.org/unix/fonts.html
. [ GIMP-NEWSYM26 ] List of new symbols in GIMP 2.6 .
libgimp-index-new-in-2-6.html
. [ GIMP-REGISTRY ] GIMP-Plugin Registry . http://registry.gimp.org
. [ GROKKING01 ] Grokking the GIMP .
http://gimp-savvy.com/BOOK/index.html
. [ GROKKING02 ] Grokking the GIMP (9.2 Clickable Image Maps) .
http://gimp-savvy.com/BOOK/index.html?node81.html
. [ GUNTHER04 ] Making shapes in GIMP . Gunther Dale . Copyright © 2004 Dale (Gunther).
http://gug.criticalhit.dk/tutorials/gunther1
. [ ICC ] INTERNATIONAL COLOR CONSORTIUM . http://www.color.org/
. [ ICCsRGB ] ICC sRGB PROFILES .
http://www.color.org/srgbprofiles.html
. [ GPL ] General Public License (GPL) .
http://www.fsf.org/licensing/licenses/gpl.html
. [ GQVIEW ] Homepage of GQview, an image browser .
http://gqview.sourceforge.net
. [ GTHUMB ]
gThumb - An Image Viewer and Browser for the GNOME Desktop
.
http://gthumb.sourceforge.net
. [ INKSCAPE ] Inkscape is an Open Source vector graphics editor . http://www.inkscape.org
. [ JIMMAC01 ] Alternative icon theme for GIMP 2.4 .
http://jimmac.musichall.cz/zip/GIMP-Greyscale-tools-0.1.tar.bz2
. [ LPROF ] LPROF ICC Profiler .
http://lprof.sourceforge.net/
. [ MSKB-294714 ] Microsoft Knowledge Base Article 294714 .
http://support.microsoft.com/kb/294714
. [ MsRGB ] Microsoft sRVB Workspace .
http://www.microsoft.com/whdc/device/display/color/default.mspx
. [ OPENCLIPART-GRADIENT ] Open Clipart - Gradients . http://openclipart.org/
. [ OPENICC ] The OpenICC project .
http://freedesktop.org/wiki/OpenIcc
. [ PLUGIN-EXIF ] GIMP-Plugin Exif Browser .
http://registry.gimp.org/plugin?id=4153
. [ PLUGIN-FLAMES ] GIMP-Plugin Flames .
http://draves.org/gimp/flame.html
;
http://flam3.com/ . [ PLUGIN-REDEYE ]
A plugin to quickly remove “ redeye ” caused by camera
flash
.
http://registry.gimp.org/plugin?id=4212
. [ PLUGIN-RESYNTH ] Resynthesizer is a Gimp plug-in for texture synthesis .
http://www.logarithmic.net/pfh/resynthesizer
. [ PLUGIN-RETINEX ] A plugin providing the Retinex algorithm for GIMP .
http://www-prima.inrialpes.fr/pelisson/MSRCR.php
. [ PLUGIN-SEPARATE ] A plugin providing rudimentary CMYK support for GIMP .
http://www.blackfiveservices.co.uk/separate.shtml
. [ PYTHON ] Python Programming Language . http://www.python.org
. [ SCALE2X ] Scale2x .
http://scale2x.sourceforge.net/
. [ SCRIBUS ] Scribus :: Open Source Desktop Publishing . http://www.scribus.net/
. [ SIOX ] Simple Interactive Object Extraction . http://www.siox.org/
. [ TUT01 ] Tutorial: How to draw straight lines . Seth Burgess . Copyright © 2002 Seth Burgess.
http://www.gimp.org/tutorials/Straight_Line
. [ TUT02 ] Tutorial: GIMPLite Quickies . Carol Spears . Copyright © 2004 Carol Spears.
http://next.gimp.org/tutorials/Lite_Quickies/
. [ UNICODE ] Unicode . http://www.unicode.org
. [ WIKIPEDIA ] Wikipedia . Wikipedia Foundation . Copyright © 2004 Wikipedia Foundation Inc.. http://www.wikipedia.org
. [ WKPD-ALPHA ] Wikipedia - Alpha channel .
http://en.wikipedia.org/wiki/Alpha_channel
. [ WKPD-BEZIER ] Wikipedia - Bézier curve .
http://en.wikipedia.org/wiki/Bezier_curve
. [ WKPD-BUMP ] Wikipedia - Bumpmap .
http://en.wikipedia.org/wiki/Bump_Mapping
. [ WKPD-BURN ] Wikipedia - Burning .
http://en.wikipedia.org/wiki/Dodging_and_burning
. [ WKPD- CA ] Wikipedia - Cellular Automata .
http://en.wikipedia.org/wiki/Cellular_Automata
. [ WKPD-CMYK ] Wikipedia - CMYK .
http://en.wikipedia.org/wiki/CMYK
. [ WKPD-COLORSPACE ] Wikipedia - Colorspace .
http://en.wikipedia.org/wiki/Colorspace
. [ WKPD-DEFLATE ] Wikipedia - Deflate .
http://en.wikipedia.org/wiki/deflate
. [ WKPD-DEINTERLACE ] Wikipedia - Deinterlace .
http://en.wikipedia.org/wiki/Deinterlace
. [ WKPD-DITHERING ] Wikipedia - Dithering .
http://en.wikipedia.org/wiki/Dithering
. [ WKPD-DODGE ] Wikipedia - Dodging .
http://en.wikipedia.org/wiki/Dodging_and_burning
. [ WKPD- EXIF ] Wikipedia - EXIF .
http://en.wikipedia.org/wiki/EXIF
. [ WKPD-FILEFORMAT ] Wikipedia - Fileformat .
http://en.wikipedia.org/wiki/Image_file_format
. [ WKPD-GAMUT ] Wikipedia - Gamut .
http://en.wikipedia.org/wiki/Gamut
. [ WKPD-GIF ] Wikipedia - GIF .
http://en.wikipedia.org/wiki/GIF
. [ WKPD-GNU ] Wikipedia - GNU .
http://en.wikipedia.org/wiki/GNU
. [ WKPD-HISTOGRAM ] Wikipedia - Histogram .
http://en.wikipedia.org/wiki/Image_histogram
. [ WKPD-HSV ] Wikipedia - HSV .
http://en.wikipedia.org/wiki/HSL_and_HSV
. [ WKPD-ICC ] Wikipedia - ICC Profile .
http://en.wikipedia.org/wiki/ICC_Profile
. [ WKPD-INTERPOL ] Wikipedia - Interpolation .
http://en.wikipedia.org/wiki/Interpolation
. [ WKPD-JPEG ] Wikipedia - JPEG .
http://en.wikipedia.org/wiki/JPEG
. [ WKPD-LAB ] Wikipedia - L*a*b .
http://en.wikipedia.org/wiki/Lab_color_space
. [ WKPD-LZW ] Wikipedia - LZW .
http://en.wikipedia.org/wiki/LZW
. [ WKPD-MOIRE ] Wikipedia - Moire .
http://en.wikipedia.org/wiki/Moire
. [ WKPD-PACKBITS ] Wikipedia - PackBits .
http://en.wikipedia.org/wiki/PackBits
. [ WKPD-PNG ] Wikipedia - PNG .
http://en.wikipedia.org/wiki/Portable_Network_Graphics
. [ WKPD-RASTER ] Wikipedia - Raster Graphics .
http://en.wikipedia.org/wiki/Raster_graphics
. [ WKPD-RI ] Wikipedia - Rendering Intent .
http://en.wikipedia.org/wiki/Rendering_intent
. [ WKPD-RETINA ] Wikipedia - Retina .
http://en.wikipedia.org/wiki/Retina
. [ WKPD-SEPIA ] Wikipedia - Sepia .
http://en.wikipedia.org/wiki/Sepia
. [ WKPD-SUBSAMPLING ] Wikipedia - Chroma subsampling .
http://en.wikipedia.org/wiki/Chroma_Subsampling
. [ WKPD-SVG ] Wikipedia - SVG .
http://en.wikipedia.org/wiki/Scalable_Vector_Graphics
. [ WKPD-URI ] Wikipedia - URI .
http://en.wikipedia.org/wiki/Uniform_Resource_Identifier
. [ WKPD-URL ] Wikipedia - URL .
http://en.wikipedia.org/wiki/Uniform_Resource_Locator
. [ WKPD-Web-colors ] Wikipedia - Web-colors .
http://en.wikipedia.org/wiki/Web_colors
. [ WKPD-YCBCR ] Wikipedia - YCbCr .
http://en.wikipedia.org/wiki/YCbCr
. [ WKPD-YUV ] Wikipedia - YUV .
http://en.wikipedia.org/wiki/YUV
. [ XDS ] Direct Save Protocol (XDS) .
http://freedesktop.org/wiki/Specifications/XDS
. [ XNVIEW ] XnView .
http://perso.orange.fr/pierre.g/xnview/enhome.html
. Glossary Appendix A. GIMP History
 Report an error in Bugzilla  2. 3. Do's and Don'ts 2.3. Do's and Don'ts 2. Using Script-Fu Scripts  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 3. Do's and Don'ts
A common error when you are dealing with Script-Fus is that you simply
bring them up and press the OK button. When nothing happens, you
probably think that the script is broken or buggy, but there is most
likely nothing wrong with it.
2.2. Installing Script-Fus 2. 4. Different Kinds Of Script-Fus  Report an error in Bugzilla  6. Customize Splash-Screen 6. Customize Splash-Screen Chapter 12. Enrich my GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. Customize Splash-Screen When you start GIMP , you see the
splash-screen displaying short status messages while
the program is loading all its components.
Of course, you can customize the splash-screen: Create a
splashes directory in your in your
personal GIMP folder
( /home/user_name/.gimp-2.8 on
Linux,
C:\Documents and Settings\user_name\.gimp-2.8\
on Windows).
Copy your image(s) into this
splashes directory. On start,
GIMP will read this directory and choose one of the
images at random.
Tip Make sure that your images aren't too small. 5. Creating Shortcuts to Menu Functions Chapter 13. Scripting
 Report an error in Bugzilla 
Chapter 15. Dialogs Chapter 15. Dialogs Part III. Function Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 15. Dialogs Table of Contents 1. Dialog Introduction 2. Image Structure Related Dialogs 2.1. Layers Dialog 2.2. Channels Dialog 2.3. Paths Dialog 2.4. Colormap Dialog 2. 5. Histogram dialog 2.6. Navigation Dialog 2.7. Undo History Dialog 3. Image-content Related Dialogs 3.1. FG/BG Color Dialog 3.2. Brushes Dialog 3.3. Patterns Dialog 3.4. Gradients Dialog 3. 5. Palettes Dialog 3.6. Tagging 3.7. Fonts Dialog 4. Image Management Related Dialogs 4.1. Buffers Dialog 4.2. Images Dialog 4.3. Document History Dialog 4.4. Templates Dialog 5. Misc. Dialogs 5.1. Tool Presets Dialog 5.2. Tool Preset Editor 5. 3. Device Status Dialog 5.4. Error Console 5. 5. Save File 5. 6. Export File 5.7. Sample Points Dialog 5.8. Pointer Dialog 1. Dialog Introduction
Dialogs are the most common means of setting options and controls in the
GIMP . The most important dialogs are explained in
this section.
6.7. GEGL Operation 2. Image Structure Related Dialogs  Report an error in Bugzilla  2. 15. Print 2. 15. Print 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 15. Print
Since the 2.4.0 release, GIMP has its own printing
module. You can set page and image up. A preview button allows you to
verify the result before printing.
Figure 16.13. The “ Print ” dialog Note
See Printing your
photos .
 2. 15. 1. Activate Command
You can access this command from the image menubar through
File → Print ,
or by using
Ctrl + P .  2. 14. Create Template 2. 16. Close
 Report an error in Bugzilla  16. Alpha to Logo Filters 16. Alpha to Logo Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. Alpha to Logo Filters 16. 1. Introduction Figure 17.369. The Alpha to Logo filters menu
These filters correspond to the
logo-generating script-fu scripts .
They add all kinds of special effects to the alpha channel of the active
layer (that is, to the pixels with a non-zero alpha value).
Note
The menu items and the corresponding functions are enabled only if the
active layer has an alpha channel . If you see that the menu items are
grayed out, try to add an alpha
channel .
The filter effect will always be applied according to the alpha values.
The alpha of any pixel has a value
ranging from 0 (transparent) to 255 (fully opaque). It is possible to
apply a filter only partially to some (or all) pixels
by using alpha values from 1 to 254.
You will notice that this is similar to
selecting pixels partially.
In fact, internally these filters always create a
selection from the
alpha channel by transferring the alpha values to the channel which
represents the selection, and then work on the selection.
How to apply an “ Alpha to Logo ” filter to a selection?
If the active layer is the background layer , make sure that an
alpha channel exists, otherwise
add an alpha channel .
Tip
If a layer name in the Layer Dialog is in bold, then this layer has
no Alpha channel .
Invert the selection:
Select → Invert .
Remove the (inverted) selection:
Edit → Clear .
Apply the “ Alpha to Logo ” filter (the filters ignore the
selection, you don't need to re-invert the selection).
15.8. Playback 16.2. 3D Outline
 Report an error in Bugzilla 
15. Animation Filters 15. Animation Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. Animation Filters 15. 1. Introduction Figure 17.354. The Animation filters menu
These are animation helpers, which let you view and optimize your
animations (by reducing their size). We gathered “ Optimize
(Difference) ” and “ Optimize (GIF) ” filters together,
because they are not much different.
14.4. Slice 15.2. Blend
 Report an error in Bugzilla  10. Artistic Filters 10. Artistic Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. Artistic Filters 10. 1. Introduction
Artistic filters create artistic effects like cubism, oil painting,
canvas...
9.3. Film 10.2. Apply Canvas
 Report an error in Bugzilla  2. Blur Filters 2. Blur Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Blur Filters 2. 1. Introduction Figure 17.2. Original for demo
This is a set of filters that blur images, or parts of them,
in various ways. If there is a selection , only the selected parts
of an image will be blurred. There may, however, be some leakage
of colors from the unblurred area into the blurred area. To help
you pick the one you want, we will illustrate what each does when
applied to the image shown at right. These are, of course, only
examples: most of the filters have parameter settings that allow
you to vary the magnitude or type of blurring.
Figure 17.3. Gaussian blur (radius 10)
The most broadly useful of these is the Gaussian blur. (Don't let
the word "Gaussian" throw you: this filter makes an image blurry
in the most basic way.) It has an efficient implementation that
allows it to create a very blurry blur in a relatively short
time.
Figure 17.4. Simple blur
If you only want to blur the image a little bit — to soften it, as it were —
you might use the simple "Blur" filter. This filter runs automatically,
without creating a dialog. The effect is subtle enough that you might not
even notice it, but you can get a stronger effect by repeating it. In GIMP
2.0 the filter shows a dialog that allows you to set a "repeat count". If
you want a strong blurring effect, this filter is too slow to be a good
choice : use a Gaussian blur instead.
Figure 17.5. Selective blur
The Selective Blur filter allows you to set a threshold so that
only pixels that are similar to each other are blurred together.
It is often useful as a tool for reducing graininess in photos
without blurring sharp edges. (In the example, note that the
graininess of the background has been reduced.) The
implementation is much slower
than a Gaussian blur, though, so you should not use it unless you
really need the selectivity.
Figure 17.6. Pixelize
The Pixelize filter produces the well-known "Abraham Lincoln"
effect by turning the image into a set of large square pixels.
(The Oilify filter, in
the Artistic Filters group, has a similar effect, but with
irregular blobs instead of perfectly square pixels.)
Note
You can find a nice explanation of the Abraham Lincoln effect
at [ BACH04 ] . You will see the
Salvador Dali's painting “ Gala Contemplating the
Mediterranean Sea ” turning to an Abraham Lincoln's portrait
when looking at it from a distance.
Figure 17.7. Motion blur
The Motion Blur filter blurs in a specific direction at each point, which
allows you to create a sense of motion: either linear, radial, or
rotational.
Finally, the Tileable Blur filter is really the same thing as a Gaussian
blur, except that it wraps around the edges of an image to help you reduce
edge effects when you create a pattern by tiling multiple copies of the
image side by side.
Note
Tileable Blur is actually implemented by a Script-Fu script that invokes
the Gaussian blur plug-in.
Chapter 17. Filters 2.2. Blur
 Report an error in Bugzilla  9. Combine Filters 9. Combine Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  9. Combine Filters 9. 1. Introduction
The combine filters associate two or more images into a single image.
8.4. Erode 9.2. Depth Merge
 Report an error in Bugzilla 
11. Decor Filters 11. Decor Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. Decor Filters 11. 1. Introduction
These filters are image-dependent Script-Fu scripts. They create
decorative borders, and some of them add some nice special effects to the
image.
10.12. Weave 11.2. Add Bevel
 Report an error in Bugzilla  4. Distort Filters 4. Distort Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. Distort Filters Figure 17.34. The Distort filters menu 4.1. Introduction
The distort filters transform your image in many different ways.
3.9. Unsharp Mask 4.2. Blinds
 Report an error in Bugzilla  7. Edge-Detect Filters 7. Edge-Detect Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. Edge-Detect Filters 7. 1. Introduction
Edge detect filters search for borders between different colors
and so can detect contours of objects.
They are used to make selections and for many artistic purposes.
Most of them are based on gradient calculation methods and give thick
border lines. Look at fig.1 which represents color intensity
variations. On the left is a slow color gradient which is not a border.
On the right is a quick variation which is an edge. Now, let us
calculate the gradient, the variation speed, of this edge, i.e. the first
derivative (fig.2). We have to decide that a border is detected when
gradient is more than a threshold value (the exact border is at top of
the curve, but this top varies according to borders). In most cases,
threshold is under top and border is thick.
The Laplacian edge detection uses the second derivative (fig.3).
The top of the curve is now at zero and clearly identified. That's
why Laplace filter renders a thin border, only a pixel wide. But
this derivative gives several zeros corresponding to small
ripples, resulting in false edges.
Some blurring before applying edge filters is often necessary: it
flattens small ripples in signal and so prevents false edges.
6.7. Spread 7.2. Difference of Gaussians  Report an error in Bugzilla 
3. Enhance Filters 3. Enhance Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Enhance Filters Figure 17.20. The Enhance filters menu 3.1. Introduction
Enhance filters are used to compensate for image imperfections. Such
imperfections include dust particles, noise, interlaced frames (coming
usually from a TV frame-grabber) and insufficient sharpness.
2.7. Tileable Blur 3.2. Antialias
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8. Generic Filters 8. Generic Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. Generic Filters 8. 1. Introduction
Generic filters are a catch-all for filters which can't be placed
elsewhere. You can find:
The Convolution Matrix
filter which lets you build custom filters.
The Dilate filter.
The Erode filter.
7.6. Sobel 8.2. Convolution Matrix
 Report an error in Bugzilla  5. Light and Shadow Filters 5. Light and Shadow Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. Light and Shadow Filters Figure 17.89. The Light and Shadow filters menu 5.1. Introduction
Here you will find three groups of filters:
The original Light Effects filters, which render
several illumination effects of the image.
Some Script-Fu and Python-Fu
scripts, which create various kinds of shadows.
Glass Effects filters result in an image as if it
were seen through a lens or glass tiles.
4.19. Wind 5.2. Gradient Flare
 Report an error in Bugzilla  12. Map Filters 12. Map Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. Map Filters 12. 1. Introduction
Map filters use an object named map to modify an
image: you map the image to the object. So, you can create 3D effects
by mapping your image to another previously embossed image
( “ Bumpmap ” Filter) or to a sphere ( “ Map Object ”
filter ). You can also map a part of the image elsewhere into the same
image ( “ Illusion ” and “ Make Seamless ” filters),
bend a text along a curve ( “ Displace ” filter)...
11.10. Stencil Chrome 12.2. Bump Map
 Report an error in Bugzilla  6. Noise Filters 6. Noise Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. Noise Filters 6. 1. Introduction
Noise filters add noise to the active layer or to the
selection. To remove small defects from an image, see
the Despeckle and
Selective Gaussian Blur filters.
5.11. Glass Tile 6.2. HSV Noise
 Report an error in Bugzilla  13. Rendering Filters 13. Rendering Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. Rendering Filters 13. 1. Introduction
Most GIMP filters work on a layer by transforming its
content, but the filters in the “ Render ” group are a bit
different. They create patterns from scratch, in most cases obliterating
anything that was previously in the layer. Some create random or noisy
patterns, others regular of fractal patterns, and one (Gfig) is a
general-purpose (but rather limited) vector graphics tool.
12.11. Warp 13.2. Difference Clouds
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14. Web Filters 14. Web Filters Chapter 17. Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  14. Web Filters 14. 1. Introduction Figure 17.343. The Web filters menu
This filters are mostly used on images mentioned for web sites. The
filter ImageMap is used to add
clickable “ hot spots ” on the image. The filter
Semi-Flatten is used to
simulate semi-transparency in image formats without alpha channel.
The Slice filter creates HTML
tables of sensitive images.
13.22. Spyrogimp 14.2. ImageMap
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Chapter 17. Filters Chapter 17. Filters Part III. Function Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 17. Filters Table of Contents 1. Introduction 1. 1. Preview 2. Blur Filters 2.1. Introduction 2.2. Blur 2.3. Gaussian Blur 2.4. Selective Gaussian Blur 2.5. Motion Blur 2. 6. Pixelise 2.7. Tileable Blur 3. Enhance Filters 3.1. Introduction 3.2. Antialias 3.3. Deinterlace 3.4. Despeckle 3.5. Destripe 3.6. NL Filter 3.7. Red Eye Removal 3.8. Sharpen 3.9. Unsharp Mask 4. Distort Filters 4.1. Introduction 4.2. Blinds 4.3. Curve Bend 4.4. Emboss 4.5. Engrave 4.6. Erase Every Other Row 4.7. IWarp 4.8. Lens Distortion 4. 9. Mosaic 4.10. Newsprint 4.11. Page Curl 4. 12. Polar Coords 4. 13. Ripple 4.14. Shift 4.15. Value Propagate 4. 16. Video 4.17. Waves 4.18. Whirl and Pinch 4.19. Wind 5. Light and Shadow Filters 5.1. Introduction 5.2. Gradient Flare 5. 3. Lens Flare 5.4. Lighting Effects 5. 5. Sparkle 5.6. Supernova 5.7. Drop Shadow 5. 8. Perspective 5.9. Xach-Effect 5. 10. Apply Lens 5.11. Glass Tile 6. Noise Filters 6.1. Introduction 6.2. HSV Noise 6. 3. Hurl 6.4. Pick 6.5. RGB Noise 6. 6. Slur 6.7. Spread 7. Edge-Detect Filters 7. 1. Introduction 7.2. Difference of Gaussians 7.3. Edge 7.4. Laplace 7.5. Neon 7.6. Sobel 8. Generic Filters 8.1. Introduction 8.2. Convolution Matrix 8. 3. Dilate 8.4. Erode 9. Combine Filters 9.1. Introduction 9.2. Depth Merge 9.3. Film 10. Artistic Filters 10.1. Introduction 10.2. Apply Canvas 10. 3. Cartoon 10.4. Clothify 10.5. Cubism 10.6. GIMPressionist 10.7. Oilify 10.8. Photocopy 10.9. Predator 10.10. Softglow 10.11. Van Gogh (LIC) 10.12. Weave 11. Decor Filters 11.1. Introduction 11.2. Add Bevel 11. 3. Add Border 11.4. Coffee Stain 11. 5. Fuzzy Border 11. 6. Old Photo 11.7. Round Corners 11. 8. Slide 11.9. Stencil Carve 11.10. Stencil Chrome 12. Map Filters 12.1. Introduction 12.2. Bump Map 12. 3. Displace 12.4. Fractal Trace 12. 5. Illusion 12.6. Make Seamless 12.7. Map Object 12. 8. Paper Tile 12. 9. Small Tiles 12. 10. Tile 12.11. Warp 13. Rendering Filters 13.1. Introduction 13.2. Difference Clouds 13. 3. Fog 13.4. Plasma 13.5. Solid Noise 13. 6. Flame 13.7. IFS Fractal 13. 8. Checkerboard 13.9. CML Explorer 13. 10. Diffraction Patterns 13. 11. Grid 13.12. Jigsaw 13.13. Maze 13.14. Qbist 13.15. Sinus 13.16. Circuit 13.17. Fractal Explorer 13. 18. Gfig 13.19. Lava 13.20. Line Nova 13.21. Sphere Designer 13.22. Spyrogimp 14. Web Filters 14.1. Introduction 14.2. ImageMap 14.3. Semi-Flatten 14.4. Slice 15. Animation Filters 15.1. Introduction 15.2. Blend 15.3. Burn-In 15.4. Rippling 15.5. Spinning Globe 15. 6. Waves 15.7. Optimize 15.8. Playback 16. Alpha to Logo Filters 16.1. Introduction 16.2. 3D Outline 16. 3. Alien Glow 16.4. Alien Neon 16. 5. Basic I & II 16.6. Blended 16.7. Bovination 16.8. Chalk 16.9. Chip Away 16. 10. Chrome 16.11. Comic Book 16. 12. Cool Metal 16. 13. Frosty 16.14. Glossy 16.15. Glowing Hot 16. 16. Gradient Bevel 16. 17. Neon 16.18. Particle Trace 16.19. Textured 1. Introduction
A filter is a special kind of tool designed to take an input layer or
image, apply a mathematical algorithm to it, and return the input layer or
image in a modified format. GIMP
uses filters to achieve a variety of effects and those effects are
discussed here.
The filters are divided into several categories: Section 2, “Blur Filters” Section 3, “Enhance Filters” Section 4, “Distort Filters” Section 5, “Light and Shadow Filters” Section 6, “Noise Filters” Section 7, “Edge-Detect Filters” Section 8, “Generic Filters” Section 9, “Combine Filters” Section 10, “Artistic Filters” Section 11, “Decor Filters” Section 12, “Map Filters” Section 13, “Rendering Filters” Section 14, “ Web Filters ” Section 15, “Animation Filters” Section 16, “Alpha to Logo Filters” 1.1. Preview
Most filters have a Preview where changes in the image are displayed, in
real time ( if the “ Preview ” option is checked), before
being applied to the image.
Figure 17. 1. Preview submenu
Right clicking on the Preview window opens a submenu which lets
you set the Style and the Size of checks representing
transparency.
12.8. GIMP online 2. Blur Filters
 Report an error in Bugzilla  3. 3. Font Problems 3.3. Font Problems 3. Text  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 3. Font Problems
Problems with fonts have probably been responsible for more GIMP 2 bug
reports than any other single cause, although they have become much less
frequent in the most recent releases in the 2.0 series. In most cases
they have been caused by malformed font files giving trouble to
Fontconfig. If you experience crashes at start-up when GIMP scans your
font directories, the best solution is to upgrade to a version of
Fontconfig newer than 2.2.0. As a quick workaround you can start gimp
with the --no-fonts
command-line option, but then you will not be able to use the text tool.
Another known problem is that Pango 1.2 cannot load fonts that don't
provide an Unicode character mapping. (Pango is the text layout library
used by GIMP.) A lot of symbol fonts fall into this category. On some
systems, using such a font can cause GIMP to crash. Updating to Pango
1.4 will fix this problem and makes symbol fonts available in GIMP.
A frequent source of confusion occurs on Windows systems, when GIMP
encounters a malformed font file and generates an error message: this
causes a console window to pop up so that you can see the message.
Do not close that console window. It is harmless, and closing it will
shut down GIMP.
When this happens, it often seems to users that GIMP has crashed. It
hasn't: closing the console window causes Windows to shut GIMP down.
Unfortunately, this annoying situation is caused by an interaction
between Windows and the libraries that GIMP links to: it cannot be fixed
within GIMP. All you need to do , though, if this happens, is minimize
the console window and ignore it.
3.2. Adding Fonts Chapter 10. Enhancing Photographs
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Part I. Getting Started Part I. Getting Started  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Part I. Getting Started Table of Contents 1. Introduction 1. Welcome to GIMP 1.1. Authors 1.2. The GIMP Help system 1.3. Features and Capabilities 2. What's New in GIMP 2.8? 2. Fire up the GIMP 1. Running GIMP 1.1. Known Platforms 1.2. Language 1.3. Command Line Arguments 2. Starting GIMP the first time 2.1. Finally . . . 3. First Steps with Wilber 1. Basic Concepts 2. Main Windows 2.1. The Toolbox 2.2. Image Window 2.3. Dialogs and Docking 3. Undoing 3.1. Things That Cannot be Undone 4. Common Tasks 4.1. Intention 4.2. Change the Size of an Image for the screen 4. 3. Change the Size of an Image for print 4.4. Compressing Images 4. 5. Crop An Image 4. 6. Find Info About Your Image 4.7. Change the Mode 4.8. Flip An Image 4. 9. Rotate An Image 4.10. Separating an Object From Its Background 5. How to Draw Straight Lines 5.1. Intention 5.2. Examples 4. Getting Unstuck 1. Getting Unstuck 1.1. Stuck! 1.2. Common Causes of GIMP Non-Responsiveness Preface Chapter 1. Introduction
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2. APPLICABILITY AND DEFINITIONS 2. APPLICABILITY AND DEFINITIONS Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work, in any medium, that
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You accept the license if you copy, modify or distribute the work in a
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Appendix C. GNU Free Documentation License 3. VERBATIM COPYING
 Report an error in Bugzilla  11. FUTURE REVISIONS OF THIS LICENSE 11. FUTURE REVISIONS OF THIS LICENSE Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions of the
GNU Free Documentation License from time to time. Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns. See
http://www.gnu.org/copyleft/ .
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If the Document specifies that a particular numbered version of this
License “ or any later version ” applies to it, you have
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10. TERMINATION 12. ADDENDUM: How to use this License for your documents  Report an error in Bugzilla  3. VERBATIM COPYING 3. VERBATIM COPYING Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. VERBATIM COPYING
You may copy and distribute the Document in any medium, either
commercially or noncommercially, provided that this License, the
copyright notices, and the license notice saying this License applies to
the Document are reproduced in all copies, and that you add no other
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of the copies you make or distribute. However, you may accept
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number of copies you must also follow the conditions in section 4 .
You may also lend copies, under the same conditions stated above, and
you may publicly display copies.
2. APPLICABILITY AND DEFINITIONS 4. COPYING IN QUANTITY
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4. COPYING IN QUANTITY 4. COPYING IN QUANTITY Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. COPYING IN QUANTITY
If you publish printed copies (or copies in media that commonly have
printed covers) of the Document, numbering more than 100, and the
Document's license notice requires Cover Texts, you must enclose the
copies in covers that carry, clearly and legibly, all these Cover Texts:
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It is requested, but not required, that you contact the authors of the
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3. VERBATIM COPYING 5. MODIFICATIONS
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5. MODIFICATIONS 5. MODIFICATIONS Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. MODIFICATIONS
You may copy and distribute a Modified Version of the Document under the
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List on the Title Page, as authors, one or more persons or entities
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and required Cover Texts given in the Document's license notice .
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Preserve any Warranty Disclaimers.
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You may add a passage of up to five words as a Front-Cover Text, and
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 Report an error in Bugzilla  6. COMBINING DOCUMENTS 6. COMBINING DOCUMENTS Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. COMBINING DOCUMENTS
You may combine the Document with other documents released under this
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combination all of the Invariant Sections of all of the original
documents, unmodified, and list them all as Invariant Sections of
your combined work in its license notice, and that you preserve all
their Warranty Disclaimers.
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 Report an error in Bugzilla  7. COLLECTIONS OF DOCUMENTS 7. COLLECTIONS OF DOCUMENTS Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. COLLECTIONS OF DOCUMENTS
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6. COMBINING DOCUMENTS 8. AGGREGATION WITH INDEPENDENT WORKS  Report an error in Bugzilla  8. AGGREGATION WITH INDEPENDENT WORKS 8. AGGREGATION WITH INDEPENDENT WORKS Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other separate
and independent documents or works, in or on a volume of a storage or
distribution medium, is called an “ aggregate ” if the
copyright resulting from the compilation is not used to limit the legal
rights of the compilation's users beyond what the individual works
permit. When the Document is included in an aggregate, this License
does not apply to the other works in the aggregate which are not
themselves derivative works of the Document.
If the Cover Text requirement of section 4
is applicable to these copies of the Document, then if the Document is
less than one half of the entire aggregate, the Document's Cover Texts
may be placed on covers that bracket the Document within the aggregate,
or the electronic equivalent of covers if the Document is in electronic
form. Otherwise they must appear on printed covers that bracket the
whole aggregate.
7. COLLECTIONS OF DOCUMENTS 9. TRANSLATION
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9. TRANSLATION 9. TRANSLATION Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  9. TRANSLATION
Translation is considered a kind of modification, so you may distribute
translations of the Document under the terms of section 5 . Replacing
Invariant Sections with translations requires special permission from
their copyright holders, but you may include translations of some or all
Invariant Sections in addition to the original versions of these
Invariant Sections. You may include a translation of this License, and
all the license notices in the Document, and any Warranty Disclaimers,
provided that you also include the original English version of this
License and the original versions of those notices and disclaimers. In
case of a disagreement between the translation and the original version
of this License or a notice or disclaimer, the original version will
prevail.
If a section in the Document is Entitled
“ Acknowledgements ” , “ Dedications ” , or
“ History ” , the requirement ( section
5 ) to Preserve its Title ( section
2 ) will typically require changing the actual title.
8. AGGREGATION WITH INDEPENDENT WORKS 10. TERMINATION
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10. TERMINATION 10. TERMINATION Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. TERMINATION
You may not copy, modify, sublicense, or distribute the Document except
as expressly provided for under this License. Any other attempt to copy,
modify, sublicense or distribute the Document is void, and will
automatically terminate your rights under this License. However, parties
who have received copies, or rights, from you under this License will
not have their licenses terminated so long as such parties remain in
full compliance.
9. TRANSLATION 11. FUTURE REVISIONS OF THIS LICENSE  Report an error in Bugzilla 
12. ADDENDUM: How to use this License for your documents 12. ADDENDUM: How to use this License for your documents Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. ADDENDUM: How to use this License for your documents
To use this License in a document you have written, include a copy of
the License in the document and put the following copyrightand license
notices just after the title page:
Copyright (c) YEAR YOUR NAME. Permission is granted to copy,
distribute and/or modify this document under the terms of the GNU Free
Documentation License , Version 1.2 or any later version published by
the Free Software Foundation ; with no Invariant Sections, no
Front-Cover Texts, and no Back-Cover Texts. A copy of the license is
included in the section entitled
“ GNU Free Documentation License ” .
If you have Invariant Sections , Front-Cover Texts and Back-Cover Texts,
replace the “ with...Texts. ” line with this:
with the Invariant Sections being LIST THEIR TITLES, with the
Front-Cover Texts being LIST, and with the Back-Cover Texts being
LIST.
If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.
If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of free
software license, such as the GNU General Public License , to permit
their use in free software.
11. FUTURE REVISIONS OF THIS LICENSE Appendix D. Eeek! There is Missing Help
 Report an error in Bugzilla  12. 5. About 12.5. About 12. The “ Help ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12.5. About
The About command shows the
About window, which displays information about
the version of The GIMP you are running
and the many authors who wrote it.
 12. 5.1. Activating the “ About ” Command
You can access this command in the image menu through
Help → About  12. 5. 2. Description of the dialog window Figure 16. 210. The “ About ” dialog window
The Credits leads to the list of contributors
to GIMP program, concerning programming, graphics and translation of
the interface.
The Licence explains how to get the licence.
12.4. Tip of the Day 12. 6. Plug-In Browser
 Report an error in Bugzilla  3. 2. Brushes Dialog 3.2. Brushes Dialog 3. Image-content Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Brushes Dialog Figure 15.31. The Brushes dialog
The “ Brushes ” dialog is used to select a brush, for use with
painting tools:
see the Brushes
section for basic information on brushes and how they are used in GIMP .
The dialog also gives you access to several functions for manipulating
brushes. You can select a brush by clicking on it in the list : it will
then be shown in the Brush/Pattern/Gradient area of the Toolbox. GIMP
comes now with 56 brushes, different from each other, because the
size, the ratio and the angle of every brush can be set in the tool
options dialog. You can also create custom brushes using the Brush Editor,
or by saving images in a special brush file format.
 3. 2. 1. Activating the Dialog
The “ Brushes ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from the Toolbox, by clicking on the brush symbol in
Brush/Pattern/Gradient area.
From an image menu:
Windows → Dockable Dialogs → Brushes ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Brushes . 
from the Tool Options dialog for any of the paint tools, by
clicking on the Brush icon button, you get a popup with similar
functionality that permits you to quickly choose a brush from the
list; if you click on the button present on the right bottom of
the popup, you open the real brush dialog.
The simplified “ Brushes ” dialog
This window has five buttons, clearly explained by help pop-ups:
Smaller previews Larger previews View as list View as Grid Open the brush selection dialog
Note that, depending on your Preferences, a brush selected with the
popup may only apply to the currently active tool, not to other
paint tools. See the Tool
Option Preferences section for more information.
3. 2.2. Using the “ Brushes ” dialog 3.2.2.1. Grid/List mode
In the Tab menu, you can choose between View as
Grid and View as List . In
Grid mode, the brush shapes are laid out in a rectangular array ,
making it easy to see many at once and find the one you are looking
for. In List mode, the shapes are lined up in a list, with the names
beside them.
In the Tab menu, the option Preview Size allows
you to adapt the size of brush previews to your liking.
Figure 15. 32. Grid/List view View as Grid View as List Grid mode
At the top of the dialog appears the name of the currently
selected brush, and its size in pixels.
In the center a grid view of all available brushes appears, with
the currently selected one outlined.
List mode
For the most part, the dialog works the same way in List mode as
in Grid mode, with one exception:
If you double-click on the name of a brush, you will be able to edit it. Note, however, that you
are only allowed to change the names of brushes that you have
created or installed yourself, not the ones that come
pre-installed with GIMP. If you try to rename a pre-installed
brush, you will be able to edit the name, but as soon as you
hit return or click somewhere else, the name will revert to
its original value. It is a general rule that you cannot
alter the resources that GIMP pre-installs for you: brushes,
patterns, gradients, etc; only ones that you create yourself.
3.2.2.2. Brush previews Figure 15.33. The “ Brushes ” dialog
When you click on a brush preview, it becomes the current brush and
it gets selected in the brush area of Toolbox and the Brush option of
painting tools. When you double- click on a brush preview, you will
activate the
Brush Editor . You can also
click on buttons at the bottom of the dialog to perform various actions.
Meaning of the small symbols at the bottom right corner of every brush
preview:
A blue corner is for brushes in normal size. You can duplicate them.
A small cross means that the brush preview is in a reduced size. You
can get it in normal size by maintaining left click on it.
A red corner is for animated brushes. If you maintain left click on
the thumbnail, the animation is played.
3.2.2. 3. Tagging
You can use tags to reorganize the brushes display.
See Section 3.6, “Tagging” .
3. 2.2.4. Buttons at the bottom
At the bottom of the dialog you find a slider and some buttons:
Spacing
This slider lets you set the distance between consecutive brush
marks when you trace out a brushstroke with the mouse pointer.
Spacing is a percentage of the brush width.
Edit Brush
This activates the
Brush Editor .
Pressing the button will open the Editor for any brush. It
only works, however, for parametric brushes: for any other type,
the Editor will show you the brush but not allow you to do
anything with it.
New Brush
This creates a new parametric brush, initializes it with a small
fuzzy round shape, and opens the Brush Editor so that you can
modify it. The new brush is automatically saved in your personal
brushes folder.
Duplicate Brush
This button is only enabled if the currently selected brush is a
parametric brush. If so, the brush is duplicated, and the Brush
Editor is opened so that you can modify the copy. The result is
automatically saved in your personal
brushes folder.
Delete Brush
This option is active for parametric brushes only.
This removes all traces of the brush, both from the dialog and
the folder where its file is stored, if you have permission to
do so. It asks for confirmation before doing anything.
Refresh Brushes
If you add brushes to your personal brushes
folder or any other folder in your brush search path, by some
means other than the Brush Editor, this button causes the list
to be reloaded, so that the new entries will be available in the
dialog.
The functions performed by these buttons can also be accessed from the
dialog pop-up menu, activated by right-clicking anywhere in the brush
grid/list, or by choosing the top item ,
Brushes menu , from the dialog Tab menu .
3.2.2.5. The “ Brushes ” context menu
Figure 15. 34. The “ Brushes ” context menu
Right clicking on a brush preview opens a context menu. This menu
has now some options which let you create elliptical
and rectangular brushes. These brushes can be feathered, but they
are not parametric brushes.
The other commands of this submenu are described with the Buttons,
except for Copy Brush Location which allows to
copy brush path into clipboard. By using the
File → Open Location ,
command, you can open the brush as a new image.
3.2.3. Brush Editor Figure 15.35. The “ Brushes ” Editor dialog
The Brush Editor, activated for a new brush.
The Brush Editor allows you to view the brush parameters of a
brush supplied by GIMP, and you can't change them. You can also create
a custom brush: click on the New Brush button to
activate the functions of the brush editor; you can select a
geometrical shape, a circle, a square or a diamond. This editor has
several elements:
The dialog bar :
As with all dialog windows, a click on the small triangle prompts a
menu allowing you to set the aspect of the Brush Editor.
The title bar : To give a name to your brush.
The preview area : Brush changes appear in real
time in this preview.
Settings : Shape
A circle, a square and a diamond are available. You will modify
them by using the following options:
Radius
Distance between brush center and edge, in the width direction. A
square with a 10 pixels radius will have a 20 pixels side. A
diamond with a 5 pixels radius will have a 10 pixels width.
Spikes
This parameter is useful only for square and diamond. With a
square, increasing spikes results in a polygon. With a diamond,
you get a star.
Hardness
This parameter controls the feathering of the brush border. Value
= 1.00 gives a brush with a sharp border (0.00-1.00).
Aspect ratio
This parameter controls the brush Width/Height ratio. A diamond
with a 5 pixels radius and an Aspect Ratio = 2, will be flattened
with a 10 pixels width and a 5 pixels height (1.0-20.0).
Angle
This angle is the angle between the brush width direction, which
is normally horizontal, and the horizontal direction,
counter-clock-wise. When this value increases, the brush width
turns counter-clock-wise (0° to 180°).
Spacing
When the brush draws a line, it actually stamps the brush icon
repeatedly. If brush stamps are very close, you get the impression
of a solid line : you get that with Spacing = 1. (1.00 to 200.0).
3.2.4. The Clipboard Brush
When you use the Copy or Cut command on an image or a selection of it,
a copy appears as a new brush in the upper left corner of the “ Brushes ” dialog. This brush will persist until you use
the Copy command again. It disappears when you close GIMP.
Figure 15. 36. A new “ Clipboard Brush ” Note
You can save this clipboard brush by using the
Edit → Paste as → New brush
as soon as it appears in the “ Brushes ” dialog. (See
Section 3.11.3, “Paste as New Brush” .)
3. Image-content Related Dialogs 3. 3. Patterns Dialog
 Report an error in Bugzilla  2. Reporting the Bug 2. Reporting the Bug Appendix B. Reporting Bugs and Requesting Enhancements  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Reporting the Bug
Okay, so you have done everything you could to make sure, and you still
think it's probably a bug. You should then go ahead and file a bug
report on the Bugzilla page.
Note
The first time you file a bug report , you will be asked to create a
Bugzilla account. The process is easy and painless, and you probably
won't even get any spam as a result.
Bugzilla: Select Classification
Go to http://bugzilla.gnome.org/enter_bug.cgi , and
select the classification “ Other ” .
If you are not logged in, you are automatically redirected to the
login page. After entering your user name (login) and password,
you get back to the “ Select Classification ” page.
Bugzilla: Pick Product
Scroll down the next page until you can select the product
“ GIMP ” .
Tip
You can skip the above steps and go directly to
http://bugzilla.gnome.org/enter_bug.cgi ?product=GIMP
(You still have to login, of course.)
Bugzilla: Enter Bug: GIMP
Selecting “ GIMP ” as product takes you to the
following bug report form, which you should fill out as follows.
Note that most of the information you enter can be changed later
by the developers if you get it wrong, so try to get it right but
don't be obsessive about it.
Enter Bug: GIMP Component
Set this to the part of GIMP that the bug
affects. Note that you get a short
“ Component Description ” in the text box next
to the list when you select a component.
You have to pick something here, but if you aren't sure, make
a guess and don't worry about it.
Version
Set this to the version of GIMP that you
are using. You always find the version in the menu of the
image window:
Help → About .
Severity
In most cases you should either leave this as
“ Normal ” or set it to “ Enhancement ” ,
if it is an enhancement request rather than a malfunction. The
maintainers will adjust the severity if they think it is
warranted.
OS (Operating System)
Set this to your OS unless you have a very good reason for
thinking that the bug applies to all operating systems.
Summary
Give a one-sentence summary that is descriptive enough so that
somebody searching for similar bugs would find your bug report
on the basis of the words this summary contains.
Description
Describe the problem. Be as specific as you can, and include
all information that you think might possibly be relevant.
The classic totally useless bug report is, “ GIMP
crashes. This program sucks ” . There is no hope that the
developers can solve a problem if they can't tell what it is.
There are more fields which are hidden by default. (Click
“ Show Advanced Fields ” to show them.) You can ignore
them, so we won't describe these fields here.
Sometimes it is very helpful to augment a bug report with a
screenshot or some other type of data. If you need to do this, click
on the button Add an attachment ,
and follow the directions. But please don't do this unless you think
the attachment is really going to be useful—and if you need to
attach a screenshot, don't make it any larger than necessary. Bug
reports are likely to remain on the system for years, so there is no
sense in wasting memory.
When you have filled out all of these things, press the
Commit button and your bug report will be
submitted. It will be assigned a number, which you may want to make
note of; you will, however, be emailed any time somebody makes a
comment on your bug report or otherwise alters it, so you will
receive reminders in any case. You can see the current state of your
bug report at any time by going to
http://bugzilla.gnome.org , entering the bug number in
one of the entry boxes and pressing the
Find or Quick Search
button.
Appendix B. Reporting Bugs and Requesting Enhancements 3. What Happens to a Bug Report after you Submit it  Report an error in Bugzilla  3. What Happens to a Bug Report after you Submit it 3. What Happens to a Bug Report after you Submit it Appendix B. Reporting Bugs and Requesting Enhancements  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. What Happens to a Bug Report after you Submit it
At any time after it is submitted, a bug report has a
“ Status ”
that describes how it is currently being handled. Here are the
possible values of Status and what they mean:
Unconfirmed
This is the initial status of a bug report , from the time it is
submitted until one of the maintainers reads it and decides
whether it is really a valid bug report. Sometimes the maintainers
aren't sure, and in the meantime leave the status as
“ Unconfirmed ” . In the worst cases, a bug report can
stay
unconfirmed for a year or longer, but this is considered a bad
thing and does not happen very often.
New
This means that the bug report has been read by one of the
maintainers, and is considered, for the moment at least, to be
valid. It does not necessarily mean that anything is going to be
done about it immediately: some bug reports, especially
enhancement requests, may be perfectly valid and still go for a
long time before anybody is able to deal with them. Many bugs, on
the other hand, are fixed within hours of being reported.
Assigned
This means that a specific person has agreed to work on the bug.
It does not, this world being the kind of world that it is, mean
that that person will actually do
anything in particular, so for practical purposes this status
means nearly the same thing as “ New ” .
Reopened
This means that the bug report was at some point considered by the
maintainers to be resolved (i.e., finished), but new information
came in that caused them to change their minds: most likely, a
change that was intended to fix the problem did not completely
work.
Needinfo
This is a status you should pay particular attention to. It means
that you did not supply enough information in your bug report to
enable anything to be done about it . In most cases, no further
action will be taken on the bug report until you supply additional
information (by adding a comment). If too much time goes by
without any input from you, the bug report will eventually be
resolved as “ Incomplete ” .
Resolved
This means that the maintainers believe that they have finished
dealing with the bug report. If you disagree, you can re-open it,
but since you cannot force anybody to work on a bug against their
will, you should have a good reason for doing so. Bugs can be
resolved in a variety of ways . Here are the possible values of
Resolution and what they mean:
Fixed
The bug report is considered valid, and
GIMP has been
changed in a way that is considered to fix it.
Wontfix
The maintainers agree that the bug report is valid, but it
would take so much effort to fix, in relation to its
importance, that it is not worth the trouble.
Duplicate
This means that the same bug has already been reported by
somebody else. If you see this resolution, you will also see
a pointer to the earlier bug report, which will often give
you a lot of useful information.
Notabug
This means that the behavior described in the bug
report is intentional. It may seem like a bug to you
(and there may be many people who agree with you), but
the program is working the way it was intended to
work, and the developers don't want to change it.
NotGnome
The bug report is valid, but it can't be addressed by
changing GIMP . Problems in operating
systems, window managers, or libraries that
GIMP depends on will often be
given this resolution. Sometimes the next appropriate step
is to file a bug report for the software that is really at
fault.
Incomplete
The bug report did not contain enough information for
anything to be done about it , and the reporter did not
respond to requests for more information. Usually a bug
report will be open for at least a month or two before it is
resolved in this way.
Invalid
Something is wrong with the form of the bug report: most
commonly, the reporter has accidentally submitted the same
bug report multiple times. (This can easily happen by
mistake with some web browsers.) Bug reports that
incorrectly describe how the program behaves may also be
resolved as Invalid.
Note
If you disagree with the resolution of a bug report, you are
always free to add your comments to it. Any comment added to any
bug report, resolved or not, causes email to be sent to the
GIMP
Bugzilla mailing list, so it will at least be seen by the
maintainers. This does not, of course, mean that they will
necessarily respond to it.
2. Reporting the Bug Appendix C. GNU Free Documentation License
 Report an error in Bugzilla  2. 2. Channels Dialog 2.2. Channels Dialog 2. Image Structure Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Channels Dialog Figure 15.7. The Channels dialog
The Channels dialog is the main interface to edit, modify and manage your
channels. Channels have a double usage. This is why the dialog is divided
into two parts : the first part for color channels and the second part for
selection masks .
Color channels apply to the image and not to a
specific layer. Basically, three primary colors are necessary to render
all the wide range of natural colors. As other digital software,
GIMP uses Red, Green, and Blue as primary colors. The
first and primary channels display the Red ,
Green , and Blue values of each
pixel in your image . Next to the channel name is a thumbnail displaying a
grayscale representation of each channel, where white is 100% and black is
0% of the primary color. Alternatively, if your image is not a colored but
a Grayscale image, there is only one primary channel called
Gray . For an Indexed image with a fixed number of
known colors there is also only one primary channel called
Indexed . Then there is a optional channel called
Alpha . This channel displays transparency values of
each pixel in your image (See Alpha
Channel in Glossary). In front of this channel is a thumbnail
displaying a grayscale representation of the transparency where white is
opaque and visible, and black is transparent and invisible. If you create
your image without transparency then the Alpha channel is not present, but
you can add it from the Layers dialog
menu . Also, if you have more than one layer in your image,
GIMP automatically creates an Alpha channel.
Note GIMP doesn't support CMYK or YUV color models. Figure 15.8. Representation of an image with channels Red channel Green channel Blue channel Alpha channel All channels
The right image is decomposed in three color channels ( red, green, and
blue) and the Alpha channel for transparency. On the right image the
transparency is displayed as a gray checkerboard. In the color channel
white is always white because all the colors are present and black is
black. The red hat is visible in the red channel but quite invisible in
the other channels. This is the same for plain green and blue which are
visible only in their own channels and invisible in others.
 2. 2. 1. Activating the Dialog
The “ Channels ” dialog is a dockable dialog; see Section 2.3, “Dialogs and Docking” for help on manipulating it.
You can access it:
from an image menu:
Windows → Dockable Dialogs → Channels ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Channels . 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Channels ” dialog from the image-menu:
Windows → Channels .
2.2.2. Using the Channel dialog 2.2. 2.1. Overview
The top channels are the color channels and the optional Alpha
channel. They are always organized in the same order and they cannot
be erased. Selection masks are described below and displayed as a list
in the dialog. Every channel appears in the list with its attributes,
including a thumbnail and its name. A right-click in a channel list
entry opens the channel context
menu .
2.2.2.2. Channel attributes
Every channel is shown in the list with its own attributes, which are
very similar to the layer
attributes :
Channel visibility
By default every channel and thus every color value is visible.
This is indicated by an “ open eye ” icon . Clicking
on the eye-symbol (or the space if the channel is not visible)
will toggle the visibility of the channel.
Chain channels
The channels representing selection masks (the new channels in
the lower part of the channel list) may be grouped using the
button with the “ chain ” symbol . Then these channels
are all affected in the same way by operations applied to any
one of them.
Primary color channels (the default channels in the upper part
of the channel list) may be grouped too. By default, all color
channels (and the alpha channel) are selected, their list
entries are highlighted. Operations will be performed on all
channels. By clicking on a channel list entry you can
deactivate this channel. Operations like
colorizing a layer
will then be applied to the selected ( “ grouped ” )
channels only. Clicking again on the list entry will activate
the channel.
Thumbnail
A small preview-icon represents the effect of the channel. On
a selection mask, this preview can be enlarged by holding
click down on it.
Channel name
The name of the channel, which must be unique within the image.
Double-clicking on the name of a selection mask channel will
allow you to edit it. The names of the primary channels (Red,
Green, Blue, Alpha) can not be changed.
Caution
Activated channels appear highlighted (generally) in blue in the
dialog. If you click on a channel in the list you toggle activation
of the corresponding channel. Disabling a color channel red, blue,
or green has severe consequences. For instance if you disable the
blue channel, all pixels from now on added to the image will not
have blue component, and so a white pixel will have the yellow
complementary color.
2.2.2.3. Managing channels
Under the channel list is a set of buttons allowing you to perform
some basic operations on channel list.
Edit Channel Attributes
Only available for selection masks. Here you can change the
Channel name . The other two parameters
affect channel visibility in the image window; they control
Opacity and color used for the mask in the
image window. A click on the color button displays the GIMP
color selector and then you can change the mask color.
New Channel
You can create here a new channel. The displayed dialog lets
you set Opacity and mask color used in
the image to represent the selection. (If you use the
New Channel button in Channel Menu,
you can create this new channel with the options previously
used by pressing the Shift key when clicking).
This new channel is a channel mask (a selection mask) applied
over the image. See
Selection Mask
Raise Channel
Only available for selection masks: you can here put the
channel up a level in the list. Press Shift
key to move channel to top of the list.
Lower Channel
You can here put the channel down a level in the list. Press the
Shift key to move the channel to bottom of the
list.
Duplicate Channel
You can create here a copy of the active channel. Name of new
channel is suffixed with a number.
Tip
You can also duplicate a color channel or the Alpha channel.
It's an easy way to keep a copy of them and to use them later
as a selection in an image.
Channel to Selection
Here you can transform the channel to become a selection. By
default the selection derived from a channel replaces any
previous active selection. It's possible to change this by
clicking on control keys.
Shift :
the selection derived from a channel is added to the
previous active selection. The final selection is merged
from both.
Ctrl :
the final selection is the subtraction of selection derived
from a channel from the previously active one.
Shift + Ctrl :
the final selection is the intersection of selection derived
from a channel with the previously active one. Only common
parts are kept.
Delete Channel
Only available for selection masks: you can here delete the
active channel.
2.2.2.4. Channels Context Menu Figure 15.9. Channel Context Menu Overview
You can get the channel context menu by right clicking on a channel
thumbnail. This menu gives the same operations on channels as those
available from dialog buttons. The only difference concerns
transformation to selection operations, each of them having its own
entry in the menu.
Edit Channel Attributes , New Channel , Raise Channel , Lower Channel , Duplicate Channel , Delete Channel
See
Managing channels .
Channel to Selection
Selection derived from channel replaces any previous active
selection.
Add to Selection
Selection derived from channel is added to previous active
selection. Final selection is merging of both.
Subtract from Selection
Final selection is subtraction of selection derived from a
channel from previous active selection.
Intersect with Selection
Final selection is intersection of selection derived from a
channel with the previous active selection. Only common parts
are kept.
2.2.3. Selection masks Figure 15.10. A selection composed out of channels.
Channels can be used to save and restore your selections.
In the channel dialog you can see a thumbnail representing the selection.
Selection Masks are a graphical way to build selections into a gray level
channel where white pixels are selected and black pixels are not selected.
Therefore gray pixels are partially selected. You can think of them as
feathering the selection, a smooth transition between selected and not
selected. This is important to avoid the ugly pixelization effect when you
fill the selection or when you erase its content after isolating a subject
from background.
Creating Selection Masks
There are several ways to initialize a selection mask.
From the image window menu
Select → Save to Channel if there is an active selection .
In the image window the bottom-left button creates a
Quick Mask ; the content
will be initialized with the active selection.
From the channel dialog, when you click on the
New channel button or from the context
menu . When created, this Selection mask appears in the
Channel dialog, named “ Selection maskcopy ” with
a queuing number. You can change this by using the context
menu that you get by right-clicking on the channel.
2.2.3.1. Using Selection Masks
Once the channel is initialized, selected (highlighted in blue), visible
(eye-icon in the dialog), and displayed as you want (color and opacity
attributes), you can start to work with all the paint tools. The colors
used are important. If you paint with some color other than white, grey,
or black, the color Value (luminosity) will be used to define a gray
(medium, light, or dark). When your mask is painted, you can transform
it to a selection by clicking on the
button ( Channel to
Selection ) or from the
context menu .
You can work in selection masks not only with the paint tool but also
with other tools. For instance, you can use the selection tools to fill
areas uniformly with gradients or patterns. By adding many selection
masks in your list you can easily compose very complex selections. One
can say that a selection mask is to a selection as a layer is to an
image.
Caution
As long as a selection mask is activated you are working in the mask
and not in the image. To work in the image you have to deactivate all
selection masks. Don't forget also to stop displaying masks in the
image by removing the eye icon. Check also that all RGB and Alpha
channels are activated and displayed in the image.
2.2.4. Quick Mask Figure 15.11. Dialog Quick Mask
A Quick Mask is a
Selection Mask
intended to be used temporarily to paint a selection. Temporarily means
that, unlike a normal selection mask, it will be deleted from the
channel list after its transformation to selection. The
selection tools
sometimes show their limits when they have to be used for doing complex
drawing selection, as progressive. In this case, using the QuickMask is a
good idea which can give very good results.
2.2. 4. 1. Activating the dialog
The QuickMask can be activated in different ways:
From the image menu:
Select → Toggle QuickMask .
By clicking the left-bottom button showed in red on the screenshot.
By using the
Shift + Q
shortcut.
2.2.4.2. Creating a Quick Mask
To initialize a Quick Mask ,
click the bottom-left button in the image window . If a selection was
active in your image, then its content appears unchanged while the
border is covered with a translucent red color. If no selection was
active then all the image is covered with a translucent red color.
Another click on the bottom-left button will deactivate the quick mask.
From the channel dialog you can double click on the name or the
thumbnail to edit the QMask attributes. Then you
can change the Opacity and its filling color. At
every moment you can hide the mask by clicking on the eye icon
in front of the QMask .
The mask is coded in gray tones, so you must use white or gray to
decrease the area limited by the mask and black to increase it. The area
painted in light or dark gray will be transition areas for the selection
like feathering. When your mask is ready, click again on the bottom-left
button in the image window and the quick mask will be removed from the
channel list and converted to a selection.
Quick mask's purpose is to paint a selection and its transitions with
the paint tools without worrying about managing selection masks. It's a
good way to isolate a subject in a picture because once the selection is
made you only have to remove its content (or inverse if the subject is
in the selection).
2.2.4. 3. Using Quick Mask with a gradient Description
Screenshot of the image window with activated QuickMask. As long as
the Quickmask is activated, all operations are done on it. A
gradient from black (left) to white (right) has been applied to the
mask.
The QuickMask is now disabled. The selection occupies the right half
part of the image (marching ants) because the limit of the selection
is at the middle of the gradient.
A stroke is now added during the enabled selection. Weird! The
gradient, although not visible, remains active all over the image,
in selected and non selected areas!
After the QuickMask Button is pressed, the command generates a
temporary 8-bit (0-255) channel, on which the progressive selection
work is stored. If a selection is already present the mask is
initialized with the content of the selection. Once QuickMask has been
activated, the image is covered by a red semi-transparent veil. This
one represents the non-selected pixels. Any
paint tool
can be used to create the selection on the QuickMask. They should use
only grayscale color, conforming the channel properties, white enabling
to define the future selected place. The selection will be displayed as
soon as the QuickMask will be toggled but its temporary channel will
not be available anymore.
Tip
To save in a channel the selection done with the Quickmask select in
the image menu
Select/Save to Channel
2.2.4.4. Usage Open an image or begin a
new document .
Activate the Quickmask using the left-bottom button in the image
window . If a selection is present the mask is initialized with the
content of the selection.
Choose a drawing tool
and use it with grayscale colors on the QuickMask.
Deactivate the Quickmask using the left-bottom button in the image
window . 2. Image Structure Related Dialogs 2. 3. Paths Dialog
 Report an error in Bugzilla  8. 6. The “Auto” Submenu 8.6. The “ Auto ” Submenu 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 6. The “ Auto ” Submenu Figure 16.124. The “ Colors/Auto ” submenu
The Auto submenu contains operations which
automatically adjust the distribution of colors in the active layer,
without requiring any input from the user. Several of these operations
are actually implemented as plugins.
8.6.1. Activate submenu
You can access this submenu from the image window through
Colors → Auto .
8.6.2. Automatic Color-Stretching GIMP has several automatic commands for stretching
the columns of the histogram for the color channels of the active layer.
By pushing bright pixels to the right and dark pixels to the left, they
make bright pixels brighter and dark pixels darker, which enhances the
contrast in the layer.
Some of the commands stretch the three color channels equally, so that
the hues are not changed. Other commands stretch each of the color
channels separately, which changes the hues.
The way the stretching is done varies with the different commands and
the results look different. It is not easy to predict exactly what each
command will do. If you know exactly what you are doing, you can get the
same results, and even more, with the
Levels tool.
Here are examples of the results of these commands, all together on one
page, so you can compare them more easily. The most appropriate command
depends upon your image, so you should try each of them to see which
command works best on it.
Figure 16.125. The original layer and its histograms
This layer doesn't have any very bright or very dark pixels, so
it works well with these commands.
Figure 16.126.
The Equalize command
“ Equalize ” example
Figure 16. 127.
The White Balance
command
“ White Balance ” example
Figure 16. 128.
The Color Enhance
command
“ Color Enhance ” example
Figure 16. 129.
The Normalize command
“ Normalize ” example
Figure 16. 130.
The Stretch Contrast
command
“ Stretch Contrast ” example
Figure 16. 131.
The Stretch HSV
command
“ Stretch HSV ” example 8.5. Use GEGL 8. 7. Equalize
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8. 13. The “Components” Submenu 8.13. The “ Components ” Submenu 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 13. The “ Components ” Submenu This command leads to the following submenu Figure 16. 144. The “ Components ” submenu
Section 8.14, “Channel Mixer” Section 8.15, “Compose” Section 8.16, “
Decompose
” Section 8.17, “Recompose”
8. 13.1. Activating the command
This command is found in the image window menu under
Colors → Components .
8.12. Stretch HSV 8.14. Channel Mixer
 Report an error in Bugzilla  8. 32. The Color Filters 8.32. The Color Filters 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Report an error in Bugzilla 
8. 28. Histogram 8.28. Histogram 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8.28. Histogram
The Histogram dialog is documented in
Section 2.5, “Histogram dialog” .
8.27. The “ Info ” Submenu 8.29. Border Average
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8. 27. The “Info” Submenu 8.27. The “ Info ” Submenu 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 27. The “ Info ” Submenu This command leads to the following submenu Figure 16. 176. The “ Info ” submenu
Section 8.28, “Histogram” Section 8.29, “Border Average” Section 8.30, “Colorcube Analysis” Section 8.31, “Smooth Palette”
8.26. Sample Colorize 8.28. Histogram
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8. 18. The “Map” Submenu 8.18. The “ Map ” Submenu 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 18. The “ Map ” Submenu This command leads to the following submenu Figure 16. 158. The “ Map ” submenu
Section 8.19, “Rearrange Colormap” Section 8.20, “Set Colormap” Section 8.21, “Alien Map” Section 8.22, “Color Exchange” Section 8.23, “Gradient Map” Section 8.24, “Palette Map” Section 8.25, “Rotate Colors” Section 8.26, “Sample Colorize”
8.17. Recompose 8.19. Rearrange Colormap
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8. The “Colors” Menu 8. The “ Colors ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. The “ Colors ” Menu 8. 1. Introduction to the “ Colors ” Menu Figure 16.120. Contents of the “ Colors ” Menu
This section describes the
Colors menu,
which contains commands that affect the color of the image .
Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
7.54. Autocrop Layer 8.2. Colors Tools
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8. 2. Colors Tools 8. 2. Colors Tools 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8.2. Colors Tools
All of the Colors tools are extensively described in
the toolbox chapter, Section 5, “Color Tools” :
Section 5.2, “Color Balance” Section 5.3, “Hue-Saturation” Section 5.4, “Colorize” Section 5.5, “Brightness-Contrast” Section 5.6, “Threshold” Section 5.7, “Levels” Section 5.8, “Curves” Section 5.9, “Posterize” Section 5.10, “Desaturate” 8. The “ Colors ” Menu 8.3. Invert
 Report an error in Bugzilla  6. Brushes 6. Brushes Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. Brushes Figure 7.15. Brush strokes example
A number of examples of brushstrokes painted using different brushes
from the set supplied with GIMP . All were
painted using the Paintbrush tool.
A brush
is a pixmap or set of pixmaps used for painting. GIMP
includes a set of
10 “ paint tools ” , which not only perform operations that you
would normally think of as painting, but also operations such as erasing,
copying, smudging, lightening or darkening, etc. All of the paint tools,
except the ink tool, use the same set of brushes. The brush pixmaps
represent the marks that are made by single “ touches ” of the
brush to the image. A brush stroke, usually made by moving the pointer
across the image with the mouse button held down, produces a series of
marks spaced along the trajectory, in a way specified by the
characteristics of the brush and the paint tool being used.
Brushes can be selected by clicking on an icon in the
Brushes dialog .
GIMP 's
current brush is shown in the
Brush/Pattern/Gradient area of the Toolbox. Clicking on the brush
symbol there is one way of activating the Brushes dialog.
When you install GIMP , it comes with a number of basic
brushes, plus a few bizarre ones that serve mainly to give you examples of
what is possible (i. e., the "green pepper" brush in the illustration).
You can also create new brushes, or download them and install them so that
GIMP will recognize them.
GIMP can use several different types of brushes . All of
them, however, are
used in the same way, and for most purposes you don't need to worry about
the differences when you paint with them . Here are the available types of
brushes:
Ordinary brushes
Most of the brushes supplied with GIMP fall into
this category. They
are represented in the Brushes dialog by grayscale pixmaps. When you
paint using them, the current foreground color (as shown in the
Color Area of the Toolbox ) is substituted for black, and the pixmap
shown in the brushes dialog represents the mark that the brush makes
on the image.
To create such a brush: Create a small image in gray levels using
zoom. Save it with the .gbr extension. Click on Refresh button in
the Brush Dialog to get it in preview without it being necessary to
restart GIMP .
Color brushes
Brushes in this category are represented by colored images in the
Brushes dialog. They can be pictures or text. When you paint with
them , the colors are used as shown; the current foreground color
does not come into play. Otherwise they work the same way as
ordinary brushes.
To create such a brush: Create a small RGBA image. For this, open
New Image, select RGB for image type and Transparent for fill type.
Draw your image and and firs save it as a .xcf file to keep its
properties. Then save it in .gbr format. Click
on the Refresh button in Brush Dialog to get
your brush without it being necessary to restart GIMP .
Tip
When you do a Copy or a Cut on a selection, you see the contents
of the clipboard (that is the selection) at the first position in
the brushes dialog. And you can use it for painting.
Figure 7.16. Selection to Brush after Copy or Cut Image hoses / Image pipes
Brushes in this category can make more than one kind of mark on an
image. They are indicated by small red triangles at the lower right
corner of the brush symbol in the Brushes dialog. They are sometimes
called "animated brushes" because the marks change as you trace out
a brushstroke. In principle, image hose brushes can be very
sophisticated, especially if you use a tablet, changing shape as a
function of pressure, angle, etc. These possibilities have never
really been exploited, however; and the ones supplied with
GIMP are relatively simple (but still
quite useful).
You will find an example on how to create such brushes in
Animated brushes
Parametric brushes
These are brushes created using the
Brush Editor , which
allows you to generate a wide variety of brush shapes by using a
simple graphical interface. A nice feature of parametric brushes
is that they are resizable . It is possible,
using the Preferences dialog, to make key
presses or mouse wheel rotations cause the current brush to
become larger or smaller, if it is a parametric brush.
Now, all brushes have a variable size. In fact, in the option box of all
painting tools there is a slider to enlarge or reduce the size of the
active brush. You can do this directly in the image window if you have
set correctly your mouse wheel; see
Varying brush size .
In addition to the brush pixmap, each GIMP brush has
one other important
property: the brush Spacing .
This represents the distance between consecutive brush-marks when a
continuous brushstroke is painted. Each brush has an assigned default
value for this, which can be modified using the Brushes dialog.
5.7. Paths and SVG files 7. Adding New Brushes
 Report an error in Bugzilla  2. 3. Dialogs and Docking 2.3. Dialogs and Docking 2. Main Windows  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 3. Dialogs and Docking 2.3. 1. Organizing Dialogs GIMP has great flexibility for arranging dialog on
your screen. A “ dialog ” is a moving window which
contains options for a tool or is dedicated to a special task. A
“ dock ” is a container which can hold a collection of
persistent dialogs, such as the Tool Options dialog, Brushes dialog,
Palette dialog, etc. Docks cannot, however, hold non- persistent dialogs
such as the Preferences dialog or an Image window.
GIMP has three default docks:
the Tool Options dock under the Toolbox in the left panel,
the Layers, Channels, Paths and Undo dock in the upper part of the
right panel ,
the Brushes, Patterns and Gradients dock in the lower part of the
right panel .
In these docks, each dialog is in its own tab.
In multi-window mode, the Toolbox is a utility
window and not a dock. In single-window mode, it belongs to
the single window.
Use
Windows → Dockable Dialogs
to view a list of dockable dialogs. Select a dockable dialog from
the list to view the dialog. If the dialog is available in a dock,
then it is made visible. If the dialog is not in a dock, the behavior
is different in multi and single window modes:
In multi-window mode, a new window, containing the dialog, appears
on the screen.
In single-window mode, the dialog is automatically docked to the
Layers-Undo dock as a tab.
You can click-and-drag a tab and drop it in the wanted place:
either in the tab bar of a dock, to integrate it in the dialog
group,
or on a docking bar that appears as a blue line when the mouse
pointer goes over a dock border, to anchor the dialog to the dock.
In multi-window mode, you can also click on the dialog title and drag it
to the wanted place.
Figure 3.7. Integrating a new dialog in a dialog group
Here, in multi-window mode, the Histogram dialog was dragged to the
tab bar of the Layers-Undo dock.
More simple: the Add tab command in the Tab menu Section 2.3.2, “Tab Menu” .
Figure 3.8. Anchoring a dialog to a dock border
The Histogram dialog dragged to the left vertical docking bar of
the right panel and the result: the dialog anchored to
the left border of the right panel. This dialog now belongs to the
right panel.
So, you can arrange dialogs in a multi-column
display, interesting if you work with two screens, one for dialogs,
the other for images .
Tip
Press TAB in an Image window to toggle the
visibility of the docks. This is useful if the docks hide a portion
of the image Window. You can quickly hide all the docks,
do your work, then display all the docs again.
Pressing TAB inside a dock to navigate
through the dock.
2.3.2. Tab Menu Figure 3.9. A dialog in a dock, with the Tab menu button highlighted.
In each dialog, you can access a special menu of tab-related operations by
pressing the Tab Menu button, as highlighted in the figure above. Exactly
which commands are shown in the menu depends on the active dialog, but
they always include operations for creating new tabs, closing or
detaching tabs.
Figure 3.10. The Tab menu of the Layers dialog.
The Tab menu gives you access to the following commands:
Context Menu
At the top of each Tab menu, an entry opens the
dialog's context menu , which contains operations specific to that
particular type of dialog. For example, the context menu for the
Layers tab is Layers Menu , which contains
a set of operations for manipulating layers.
Add Tab Add Tab opens into a submenu allowing you to
add a large variety of dockable dialogs as new tabs.
Figure 3.11. “ Add tab ” sub-menu Close Tab
Close the dialog. Closing the last dialog in a dock
causes the dock itself to close.
Detach Tab
Detach the dialog from the dock, creating a new dock
with the detached dialog as its only member. It has the same
effect as dragging the tab out of the dock and releasing it at a
location where it cannot be docked.
It's a way to create a paradoxical new window in single-window mode!
If the tab is locked ,
this menu item is insensitive and grayed out.
Lock Tab to Dock
Prevent the dialog from being moved or detached. When activated,
Detach Tab is insensitive and grayed
out.
Preview Size Figure 3.12. Preview Size submenu of a Tab menu.
Many, but not all, dialogs have Tab menus containing a
Preview Size
option, which opens into a submenu giving a list of sizes for the
items in the dialog (see the figure above).
For example, the Brushes dialog shows pictures of all available
brushes: the Preview Size determines how large the pictures are.
The default is Medium .
Tab Style Figure 3.13. Tab Style submenu of a Tab menu.
Available only when multiple dialogs are in the same dock,
Tab Style opens a submenu allowing you
to choose the appearance of the tabs at the top (see the figure
above). There are five choices, not all are available for every
dialog:
Icon
Use an icon to represent the dialog type.
Current Status
Is only available for dialogs that allows you
to select something, such as a brush, pattern,
gradient, etc. Current Status
shows a representation of the currently selected
item in the tab top.
Text
Use text to display the dialog type.
Icon and Text
Using both an icon and text results in wider tabs.
Status and Text
Show the currently selected item and text with the dialog
type.
View as List; View as Grid
These entries are shown in dialogs that allow you to select an
item from a set: brushes, patterns, fonts, etc. You can choose
to view the items as a vertical list, with the name of
each beside it, or as a grid, with representations of the items
but no names. Each has its advantages: viewing as a list gives you
more information, but viewing as a grid allows you to see
more possibilities at once. The default for this varies across
dialogs: for brushes and patterns, the default is a grid; for most
other things, the default is a list.
When the tree-view is View as List , you can
use tags. Please see Section 3.6, “Tagging” .
You can also use a list search field:
Figure 3.14. The list search field.
Use
Ctrl + F
to open the list search field. An item must be selected for
this command to be effective.
The list search field automatically closes after five seconds
if you do nothing.
Note
The search field shortcut is also available for the tree-view you
get in the “ Brush ” , “ Font ” or
“ Pattern ” option of several tools.
Show Button Bar
Some dialogs display a button bar on the bottom of the dialog; for
example, the Patterns, Brushes, Gradients, and Images dialogs.
This is a toggle. If it is checked, then the Button Bar is
displayed.
Figure 3.15. Button Bar on the Brushes dialog. Show Image Selection
This option is available in multi-window mode only.
This is a toggle. If it is checked, then an Image Menu is shown at
the top of the dock :
Figure 3.16. A dock with an Image Menu highlighted.
It is not available for dialogs docked below the Toolbox. This
option is interesting only if you have several open images on your
screen .
Auto Follow Active Image
This option is available in multi-window mode only.
This option is also interesting only if you have several images
open on your screen. Then, the information displayed in a dock
is always that of the selected image in the Image Selection
drop-down list. If the Auto Follow Active Image
is disabled, the image can be selected only in the
Image Selection. If enabled, you can also select it by
activating the image directly (clicking on its title bar).
2.2. Image Window 3. Undoing
 Report an error in Bugzilla 
10. Gradients 10. Gradients Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. Gradients Figure 7.23. Some examples of GIMP gradients.
Gradients from top to bottom: FG to BG (RGB); Full saturation
spectrum; Nauseating headache; Browns; Four bars
A gradient
is a set of colors arranged in a linear order. The most basic use of
gradients is by the Blend tool ,
sometimes known as the “ gradient tool ” or “ gradient
fill tool ” : it works
by filling the selection with colors from a gradient. You have many
options to choose from for controlling the way the gradient colors are
arranged within the selection. There are also other important ways to use
gradients, including:
Painting with a gradient
Each of GIMP 's basic painting tools allows you
the option of using
colors from a gradient . This enables you to create brushstrokes that
change color from one end to the other.
The Gradient Map filter
This filter is now in the Colors menu, and allows you to
“ colorize ”
an image, using the color intensity of each point with the
corresponding color from the active gradient (the intensity 0, very
dark, is replaced by the color at most left end of the gradient,
progressively until the intensity is 255, very light, replaced by
the most right color of the gradient. See
Section 8.23, “Gradient Map” for more information.
When you install GIMP , it comes presupplied with a
large number of
interesting gradients, and you can add new ones that you create or
download from other sources. You can access the full set of available
gradients using the
Gradients dialog ,
a dockable dialog that you can either activate when you need it, or keep
around as a tab in a dock. The “ current gradient ” , used in
most gradient- related operations, is shown in the Brush/Pattern/Gradient
area of the Toolbox. Clicking on the gradient symbol in the Toolbox is an
alternative way of bringing up the Gradients dialog.
Many quickly examples of working with gradient (for more information
see Blend Tool ):
Put a gradient in a selection : Choose a gradient.
With the Blend Tool click and drag with the mouse between
two points of a selection.
Colors will distributed perpendicularly to the direction
of the drag of the mouse and according to the length
of it.
Figure 7.24. How to use rapidly a gradient in a selection Painting with a gradient:
You can also use a gradient with the Pencil, Paintbrush or Airbrush
tools if you choose the dynamics Color From Gradient .
In the next step choose a suitable gradient from
Color options and in the
Fade options set the gradients length
and the style of the repeating. The chapter
Section 3.2.6, “Dynamics Options” describes these
parameters in more detail.
The following example shows the impact on the Pencil tool.
You see in the upper side of the figure the necessary settings
and the lower side of the figure shows the resulting succession
of the gradients colors.
Figure 7.25. How to use rapidly a gradient with a drawing tool
To use the Paint tools with the same settings as they were known
as option Use color from gradient in GIMP
up to version 2.6 open the
Tool Presets Dialog .
Then choose one of the items Airbrush (Color From
Gradient) ,
Paintbrush (Color From Gradient) or
Pencil (Color From Gradient) from it.
Different productions with the same gradient: Figure 7.26. Gradient usage
Four ways of using the Tropical Colors gradient: a linear gradient
fill, a shaped gradient fill, a stroke painted using colors from a
gradient , and a stroke painted with a fuzzy brush then colored
using the Gradient Map
filter .
A few useful things to know about GIMP 's
gradients:
The first four gradients in the list are special: they use the
Foreground and Background colors from the Toolbox Color Area,
instead of being fixed. FG to BG (RGB) is the
RGB representation of the gradient from the Foreground color to the
Background color in Toolbox. FG to BG (HSV
counter- clockwise) represents the hue succession in
Color Circle from the selected hue to 360°. FG to BG
(HSV clockwise represents the hue succession in Color
Circle from the selected hue to 0°. With FG to transparent
, the selected hue becomes more and more transparent. You
can modify these colors by using the Color Selector. Thus, by
altering the foreground and background colors, you can make these
gradients transition smoothly between any two colors you want.
Gradients can involve not just color changes, but also changes in
opacity. Some of the gradients are completely opaque; others include
transparent or translucent parts. When you fill or paint with a
non-opaque gradient, the existing contents of the layer will show
through behind it.
You can create new custom gradients,
using the Gradient
Editor . You cannot modify the gradients that are
supplied with GIMP , but you can duplicate them or
create new ones, and then edit those.
The gradients that are supplied with GIMP are stored in
a system gradients folder. By default, gradients
that you create are stored in a folder called
gradients in your personal GIMP
directory . Any gradient files (ending with the extension
.ggr ) found in one of these folders, will
automatically be loaded when you start GIMP . You can
add more
directories to the gradient search path, if you want to, in the
Gradients tab of the Data
Folders pages of the Preferences dialog.
New in GIMP 2.2 is the ability to load gradient files
in SVG format, used
by many vector graphics programs. To make GIMP load an
SVG gradient file,
all you need to do is place it in the gradients
folder of your personal GIMP directory , or any other
folder in your gradient search path.
Tip
You can find a large number of interesting SVG gradients on the web, in
particular at OpenClipArt Gradients
[ OPENCLIPART-GRADIENT ] .
You won't be able to see what these gradients look like unless your
browser supports SVG, but that won't prevent you from downloading them.
9.2. Creating a brush quickly 11. Patterns
 Report an error in Bugzilla  2. Grids and Guides 2. Grids and Guides Chapter 12. Enrich my GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Grids and Guides
You will probably have it happen many times that you need to place
something in an image very precisely, and find that it is not easy to do
using a mouse. Often you can get better results by using the arrow keys on
the keyboard (which move the affected object one pixel at a time, or 25
pixels if you hold down the Shift
key ), but GIMP also provides you with two other aids to
make positioning easier: grids and guides.
Figure 12.27. Image used for examples below 2.1. The Image Grid Figure 12.28. Image with default grid
Each image has a grid. It is always present, but by default it is not
visible until you activate it by toggling
View → Show Grid
in the image menu . If you want grids to be present more often than not,
you can change the default behavior by checking " Show grid" in the
Image Window Appearance page of the Preferences dialog. (Note that there are separate settings
for Normal Mode and Fullscreen Mode.)
The default grid appearance, set up when you install
GIMP , consists of
plus-shaped black crosshairs at the grid line intersections, with grid
lines spaced every 10 pixels both vertically and horizontally. You can
customize the default grid using the
Default Image Grid
page of the Preferences dialog. If you only want to change the grid
appearance for the current image, you can do so by choosing
Image → Configure Grid
from the image menu : this brings up the
Configure Grid dialog.
Figure 12.29. A different grid style
Not only can a grid be helpful for judging distances and spatial
relationships, it can also permit you to align things exactly with
the grid, if you toggle
View → Snap to Grid in the image menu : this causes the pointer to "warp" perfectly to
any grid line located within a certain distance. You can
customize the snap distance threshold by setting "Snap distance"
in the Tool Options
page of the Preferences dialog, but most people seem to be happy
with the default value of 8 pixels. (Note that it is perfectly
possible to snap to the grid even if the grid is not visible. It
isn't easy to imagine why you might want to do this , though.)
Chapter 12. Enrich my GIMP 2.2. Guides
 Report an error in Bugzilla  2. 2. Guides 2.2. Guides 2. Grids and Guides  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Guides Figure 12.30. Image with four guides
In addition to the image grid, GIMP also gives you a
more flexible type of positioning aid: guides .
These are horizontal or vertical lines you can temporarily display on an
image while you are working on it .
To create a guide, simply click on one of the rulers in the image window
and pull out a guide, while holding the
mouse button pressed. The guide is then
displayed as a blue, dashed line, which follows the pointer. As soon as
you create a guide, the “ Move ” tool is activated and the
mouse pointer changes to the Move icon.
You can also create a guide with the
New Guide command, which
allows you to precisely place the guide on the image, the
New Guide (by
Percent) command , or the
New Guides from
Selection command .
You can create as many guides as you like, positioned wherever you like.
To move a guide after you have created it, activate the Move tool in the
Toolbox (or press the M key), you can then click and
drag a guide. To delete a guide, simply drag it outside the image.
Holding down the Shift key , you can move everything but
a guide, using the guides as an effective alignment aid.
The behavior of the guides depends upon the Move
(Affect) mode of the “ Move ” tool . When
Layer mode is selected, the mouse pointer turns
into a small hand as soon as it gets close to a guide. Then the guide is
activated and it turns red, and you can move the guide or delete it by
moving it back into the ruler. If Selection mode is
selected, you can position a guide, but you cannot move it after that.
As with the grid, you can cause the pointer to snap to nearby
guides, by toggling
View → Snap to Guides in the image menu . If you have a number of guides and they are
making it difficult for you to judge the image properly, you can
hide them by toggling
View → Show Guides .
It is suggested that you only do this momentarily, otherwise you
may get confused the next time you try to create a guide and
don't see anything happening.
If it makes things easier for you, you can change the default behavior
for guides in the
Image Windows
Appearance page of the Preferences dialog. Disabling
Show guides is probably a bad idea, though,
for the reason just given.
You can remove the guides with the
Image → Guides → Remove all Guides
command.
Note
Another use for guides: the
Guillotine plugin can use
guides to slice an image into a set of sub-images.
2. Grids and Guides 3. Rendering a Grid
 Report an error in Bugzilla  2. Layer Modes 2. Layer Modes Chapter 8. Combining Images  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Layer Modes GIMP has twenty-one layer modes. Layer modes are also
sometimes called “ blending modes ” .
Selecting a layer mode changes the appearance of the layer or image,
based on the layer or layers beneath it. If there is only one layer , the
layer mode has no effect. There must therefore be at least two layers in
the image to be able to use layer modes.
You can set the layer mode in the Mode
menu in the Layers dialog. GIMP
uses the layer mode to determine how to combine each pixel in the top
layer with the pixel in the same location in the layer below it.
Note
There is a drop-down list in the Toolbox options box which contains
modes that affect the painting tools in a similar way to the layer
modes. You can use all of the same modes for painting that are available
for layers, and there are two additional modes just for the painting
tools. See Section 3.3, “Brush Tools (Pencil, Paintbrush, Airbrush)” .
Layer modes permit complex color changes in the image. They are often used
with a new layer which acts as a kind of mask. For example, if you put a
solid white layer over an image and set the layer mode of the new layer to
“ Saturation ” , the underlying visible layers will appear in
shades of gray.
Figure 8.8. Images (masks) for layer mode examples Mask 1 Mask 2 Figure 8.9. Images (backgrounds) for layer mode examples Key fob Ducks
In the descriptions of the layer modes below, the equations are also
shown. This is for those who are curious about the mathematics of the
layer modes. You do not need to understand the equations in order to use
the layer modes effectively, however.
The equations are in a shorthand notation. For example, the equation
Equation 8.1. Example
means,
“
For each pixel in the upper ( M ask)and lower
( I mage) layer, add each of the
corresponding color components together to form the
E resulting pixel's color.
”
Pixel color components must always be between 0 and 255.
Note
Unless the description below says otherwise, a negative color component
is set to 0 and a color component larger than 255 is set to 255.
The examples below show the effects of each of the modes.
Since the results of each mode vary greatly depending upon the colors on
the layers, these images can only give you a general idea of how the modes
work. You are encouraged to try them out yourself. You might start with
two similar layers, where one is a copy of the other, but slightly
modified (by being blurred, moved, rotated, scaled, color-inverted, etc.)
and seeing what happens with the layer modes.
Normal Figure 8.10. Example for layer mode “ Normal ”
Both images are blended into each other with the same
intensity.
With 100% opacity only the upper layer is shown when blending
with “ Normal ” .
Normal
mode is the default layer mode. The layer on top covers the layers
below it. If you want to see anything below the top layer when you
use this mode, the layer must have some transparent areas.
The equation is: Equation 8.2. Equation for layer mode “ Normal ” Dissolve Figure 8.11. Example for layer mode “ Dissolve ”
Both images are blended into each other with the same
intensity.
With 100% opacity only the upper layer is shown when blending
with “ dissolve ” .
Dissolve
mode dissolves the upper layer into the layer beneath it by drawing
a random pattern of pixels in areas of partial transparency. It is
useful as a layer mode, but it is also often useful as a painting
mode.
This is especially visible along the edges within an image. It is
easiest to see in an enlarged screenshot. The image on the left
illustrates “ Normal ” layer mode (enlarged) and the
image on the right shows the same two layers in
“ Dissolve ”
mode, where it can be clearly seen how the pixels are dispersed.
Figure 8.12. Enlarged screenshots Normal mode. Dissolve mode. Multiply Figure 8.13.  Example for layer mode “ Multiply ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Multiply
mode multiplies the pixel values of the upper layer with those of
the layer below it and then divides the result by 255. The result is
usually a darker image. If either layer is white, the resulting
image is the same as the other layer (1 * I = I). If either layer
is black, the resulting image is completely black (0 * I = 0).
The equation is: Equation 8. 3. Equation for layer mode “ Multiply ”
The mode is commutative; the order of the two layers doesn't matter.
Divide Figure 8.14.  Example for layer mode “ Divide ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Divide
mode multiplies each pixel value in the lower layer by 256 and then
divides that by the corresponding pixel value of the upper layer
plus one. (Adding one to the denominator avoids dividing by zero.)
The resulting image is often lighter, and sometimes looks
“ burned out ” .
The equation is: Equation 8.4. Equation for layer mode “ Divide ” Screen Figure 8.15.  Example for layer mode “ Screen ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Screen
mode inverts the values of each of the visible pixels in the two
layers of the image. (That is , it subtracts each of them from 255.)
Then it multiplies them together, divides by 255 and inverts
this value again. The resulting image is usually brighter, and
sometimes “ washed out ”
in appearance. The exceptions to this are a black layer, which does
not change the other layer, and a white layer, which results in a
white image. Darker colors in the image appear to be more
transparent.
The equation is: Equation 8.5. Equation for layer mode “ Screen ”
The mode is commutative; the order of the two layers doesn't matter.
Overlay Figure 8.16.  Example for layer mode “ Overlay ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Overlay
mode inverts the pixel value of the lower layer, multiplies it by
two times the pixel value of the upper layer , adds that to the
original pixel value of the lower layer, divides by 255, and then
multiplies by the pixel value of the original lower layer and
divides by 255 again. It darkens the image, but not as much as with
“ Multiply ” mode.
The equation is:
[5]
Equation 8.6. Equation for layer mode “ Overlay ” Dodge Figure 8.17.  Example for layer mode “ Dodge ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Dodge
mode multiplies the pixel value of the lower layer by 256 , then
divides that by the inverse of the pixel value of the top layer. The
resulting image is usually lighter , but some colors may be inverted.
In photography, dodging is a technique used in a darkroom to
decrease the exposure in particular areas of the image. This brings
out details in the shadows. When used for this purpose, dodge may
work best on Grayscale images and with a painting tool, rather than
as a layer mode.
The equation is: Equation 8. 7. Equation for layer mode “ Dodge ” Burn Figure 8.18.  Example for layer mode “ Burn ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Burn
mode inverts the pixel value of the lower layer, multiplies it by
256, divides that by one plus the pixel value of the upper layer ,
then inverts the result. It tends to make the image darker, somewhat
similar to “ Multiply ” mode.
In photography, burning is a technique used in a darkroom to
increase the exposure in particular areas of the image. This brings
out details in the highlights. When used for this purpose, burn may
work best on Grayscale images and with a painting tool, rather than
as a layer mode.
The equation is: Equation 8. 8. Equation for layer mode “ Burn ” Hard light Figure 8.19.  Example for layer mode “ Hard light ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity.  Hard light
mode is rather complicated because the equation consists of two
parts, one for darker colors and one for brighter colors. If the
pixel color of the upper layer is greater than 128, the layers are
combined according to the first formula shown below. Otherwise, the
pixel values of the upper and lower layers are multiplied together
and multiplied by two, then divided by 256. You might use this mode
to combine two photographs and obtain bright colors and sharp edges.
The equation is complex and different according to
the value & gt;128 or ≤ 128: Equation 8.9.
Equation for layer mode “ Hard light ” , M & gt; 128
Equation 8.10.
Equation for layer mode “ Hard light ” , M ≤ 128
Soft light Figure 8.20.  Example for layer mode “ Soft light ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity.  Soft light is not related to
“ Hard light ” in anything but the name, but it
does tend to make the edges softer and the colors not so
bright. It is similar to “ Overlay ” mode. In some
versions of GIMP , “ Overlay ”
mode and “ Soft light ” mode are identical.
The equation is complicated. It needs Rs, the
result of Screen mode :
Equation 8.11. Equation for layer mode “ Screen ” Equation 8.12. Equation for layer mode “ Soft light ” Grain extract Figure 8.21.  Example for layer mode “ Grain extract ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Grain extract
mode is supposed to extract the “ film grain ”
from a layer to produce a new layer that is pure grain, but it can
also be useful for giving images an embossed appearance. It
subtracts the pixel value of the upper layer from that of the lower
layer and adds 128.
The equation is: Equation 8. 13. Equation for layer mode “ Grain extract ” Grain merge
There are two more layer modes, but these are available only for
painting tools. See
Painting Modes
for detailed information.
Figure 8.22.  Example for layer mode “ Grain merge ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Grain merge mode merges a grain layer
(possibly one created from the “ Grain extract ”
mode) into the current layer, leaving a grainy version of the
original layer. It does just the opposite of
“ Grain extract ” . It adds the pixel values of the
upper and lower layers together and subtracts 128.
The equation is: Equation 8. 14. Equation for layer mode “ Grain merge ” Difference Figure 8.23.  Example for layer mode “ Difference ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Difference
mode subtracts the pixel value of the upper layer from that of the
lower layer and then takes the absolute value of the result. No
matter what the original two layers look like, the result looks
rather odd. You can use it to invert elements of an image.
The equation is: Equation 8. 15. Equation for layer mode “ Difference ”
The mode is commutative; the order of the two layers doesn't matter.
Addition Figure 8.24.  Example for layer mode “ Addition ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Addition
mode is very simple. The pixel values of the upper and lower layers
are added to each other. The resulting image is usually lighter . The
equation can result in color values greater than 255, so some of the
light colors may be set to the maximum value of 255.
The equation is: Equation 8.16. Equation for layer mode “ Addition ”
The mode is commutative; the order of the two layers doesn't matter.
Subtract Figure 8.25.  Example for layer mode “ Subtract ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Subtract
mode subtracts the pixel values of the upper layer from the pixel
values of the lower layer. The resulting image is normally darker.
You might get a lot of black or near-black in the resulting image.
The equation can result in negative color values, so some of the
dark colors may be set to the minimum value of 0.
The equation is: Equation 8. 17. Equation for layer mode “ Subtraction ” Darken only Figure 8.26.  Example for layer mode “ Darken only ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity.  Darken only
mode compares each component of each pixel in the upper layer with
the corresponding one in the lower layer and uses the smaller value
in the resulting image. Completely white layers have no effect on
the final image and completely black layers result in a black image.
The equation is: Equation 8. 18. Equation for layer mode “ Darken only ” The mode is commutative; the order of the two layers doesn't matter.
Lighten only Figure 8.27.  Example for layer mode “ Lighten only ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity.  Lighten only
mode compares each component of each pixel in the upper layer with
the corresponding one in the lower layer and uses the larger value
in the resulting image. Completely black layers have no effect on
the final image and completely white layers result in a white image.
The equation is: Equation 8. 19. Equation for layer mode “ Lighten only ”
The mode is commutative; the order of the two layers doesn't matter.
Hue Figure 8.28.  Example for layer mode “ Hue ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Hue
mode uses the hue of the upper layer and the saturation and value of
the lower layer to form the resulting image. However, if the
saturation of the upper layer is zero, the hue is taken from the
lower layer, too.
Saturation Figure 8.29.  Example for layer mode “ Saturation ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Saturation
mode uses the saturation of the upper layer and the hue and value of
the lower layer to form the resulting image.
Color Figure 8.30.  Example for layer mode “ Color ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Color
mode uses the hue and saturation of the upper layer and the value of
the lower layer to form the resulting image.
Value Figure 8.31.  Example for layer mode “ Value ”
Mask 1 is used as upper layer with 100% opacity.
Mask 2 is used as upper layer with 100% opacity. 
Value
mode uses the value of the upper layer and the saturation and hue of
the lower layer to form the resulting image. You can use this mode
to reveal details in dark and light areas of an image without
changing the saturation.
Each layer in an image can have a different layer mode. (Of course, the
layer mode of the bottom layer of an image has no effect.) The effects of
these layer modes are cumulative. The image shown below has three layers.
The top layer consists of Wilber surrounded by transparency and has a
layer mode of “ Difference ” .
The second layer is solid light blue and has a layer mode of
“ Addition ” . The bottom layer is filled with the
“ Red Cubes ” pattern.
Figure 8.32. Multi layer example GIMP also has similar modes which are used for the
painting tools. These are the same twenty-one modes as the layer modes,
plus additionally two modes which are specific to the painting tools. You
can set these modes from the Mode menu in the Tools
option dialog. In the equations shown above, the layer you are painting on
is the “ lower layer ” and the pixels painted by the tool are
the “ upper layer ” . Naturally, you do not need more than one
layer in the image to use these modes, since they only operate on the
current layer and the selected painting tool.
See Section 3.1.3, “Paint Mode Examples” for a description of the
two additional painting modes.
[5]
The equation is the *theoretical* equation. Due to
Bug
#162395 , the actual equation is equivalent to Soft
light. It is difficult to fix this bug without changing the
appearance of existing images.
Chapter 8. Combining Images 3. Creating New Layers
 Report an error in Bugzilla  2. Main Windows 2. Main Windows Chapter 3. First Steps with Wilber  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Main Windows
The GIMP user interface is now available in two modes:
multi-window mode ,
single window mode.
When you open GIMP for the first time, it opens in multi-window mode by
default. You can enable single-window mode through
Windows → & gt;Single-Window Mode ) in the image menu bar.
After quitting GIMP with this option enabled, GIMP will start in
single-window mode next time.
Multi-Window Mode Figure 3. 2.
A screenshot illustrating the multi-window mode.
The screenshot above shows the most basic arrangement of
GIMP windows that can be used effectively.
You can notice two panels, left and right, and an image window in
middle. A second image is partially masked. The left panel collects
Toolbox and Tool Options dialog together. The right panel collects
layers, channels, paths, undo history dialogs together in a
multi-tab dock, brushes, patterns and gradients dialogs
together in another dock below. You can move these panels on
screen. You can also mask them using the Tab key.
The Main Toolbox:
Contains a set of icon buttons used to select tools.
By default, it also contains the foreground and background colors.
You can add brush, pattern, gradient and active image icons.
Use
Edit → Preferences → Toolbox
to enable, or disable the extra items.
Tool options:
Docked below the main Toolbox is a Tool Options dialog, showing
options for the currently selected tool (in this case, the
Move tool).
Image windows:
Each image open in GIMP is displayed in a
separate window. Many images can be open at the same time , limited
by only the system resources. Before you can do anything useful in
GIMP , you need to have at least one image
window open. The image window holds the Menu of the main commands
of GIMP (File, Edit, Select...), which you can
also get by right-clicking on the window.
An image can be bigger than the image window. In that case, GIMP
displays the image in a reduced zoom level which allows to see the
full image in the image window . If you turn to the 100% zoom
level, scroll bars appear, allowing you to pan across the image .
The Layers, Channels, Paths, Undo History
dock — note that the dialogs in the dock are tabs.
The Layers tab is open : it shows the layer structure of
the currently
active image , and allows it to be manipulated in a variety of
ways . It is possible to do a few very basic things without using
the Layers dialog, but even moderately sophisticated
GIMP users find it indispensable to have the
Layers dialog available at all times.
Brushes/Patterns/Gradients:
The docked dialog below the layer dialog shows the dialogs (tabs)
for managing brushes, patterns and gradients.
Dialog and dock managing is described in
Section 2. 3, “Dialogs and Docking” .
Single Window Mode Figure 3.3.
A screenshot illustrating the single-window mode.
You find the same elements, with differences in their management:
Left and right panels are fixed; you can't move them. But you
can decrease or increase their width. If you reduce the width of
a multi-tab dock, there may be not enough place for all tabs;
then arrow-heads appear allowing you to scroll through tabs.
As in multi-window mode, you can mask these panels using the
Tab key.
The image window occupies all space between both panels.
When several images are open, a new bar appears above the image
window, with a tab for every image. You can navigate between
images by clicking on tabs or either using
Ctrl + PageUp or
PageDown or
Alt + Number .
“ Number ” is tab number; you must use the number
keys of the upper line of your keyboard, not that of keypad
(Alt-shift necessary for some national keyboards).
This is a minimal setup. There are over a dozen other types of dialogs
used by GIMP for various purposes, but users typically
open them when they need them and close them when they are done.
Knowledgeable users generally keep the Toolbox (with Tool Options) and
Layers dialog open at all times. The Toolbox is essential to many
GIMP operations. The Tool Options section is actually
a separate dialog, shown docked to the Main Toolbox in the screenshot.
Knowledgeable users almost always have it set up this way: it is very
difficult to use tools effectively without being able to see how their
options are set. The Layers dialog comes into play when you work with an
image with multiple layers: after you advance beyond the most basic stages
of GIMP expertise, this means
almost always .
And of course it helps to display the images you're editing on the screen;
if you close the image window before saving your work,
GIMP will ask you whether you want to close the file.
Note
If your GIMP layout is lost, your arrangement
is easy to recover using
Windows → Recently Closed Docks
; the Windows menu command is only available while an image is open.
To add, close, or detach a tab from a dock, click
in the upper right corner of a dialog. This opens the Tab menu. Select
Add Tab , Close Tab
, or Detach Tab .
The following sections walk you through the components of each of the
windows shown in the screenshot, explaining what they are and how they
work. Once you have read them, plus the section describing the basic
structure of GIMP images, you should have learned
enough to use GIMP for a
wide variety of basic image manipulations. You can then look through the
rest of the manual at your leisure (or just experiment) to learn the
almost limitless number of more subtle and specialized things that are
possible. Have fun!
2.1. The Toolbox Figure 3.4. Screenshot of the Toolbox
The Toolbox is the heart of GIMP .
Here is a quick tour of what you will find there.
Tip
In the Toolbox, as in most parts of GIMP , moving the
mouse over something and letting it rest for a moment, usually displays
a “ tooltip ” that describes the thing. Short cut keys are
also frequently shown in the tooltip. In many cases, you can hover the
mouse over an item and press the F1 key to get help
about the thing that is underneath the mouse.
By default, only the Foreground-background icon is visible. You can add
Brush-Pattern- Gradient icons and Active Image icon through
Edit → Preferences → Toolbox :
Tools configuration .
Tool icons: These icons are buttons which
activate tools for a wide variety of purposes: selecting parts of
images, painting an image, transforming an image, etc.
Section 1, “The Toolbox” gives an overview of how to work with
tools, and each tool is described systematically in the
Tools chapter.
Foreground/Background colors:
The color areas here show you GIMP 's current
foreground and background
colors, which come into play in many operations. Clicking on either
one of them brings up a color selector dialog that allows you to
change to a different color. Clicking on the double-headed arrow swaps
the two colors, and clicking on the small symbol in the lower left
corner resets them to black and white.
Brush/Pattern/Gradient:
The symbols here show you GIMP's
current selections for: the Paintbrush, used by all tools that allow
you to paint on the image ( “ painting ” includes
operations like erasing and smudging, by the way); for the Pattern,
which is used in filling selected areas of an image; and for the
Gradient, which comes into play whenever an operation requires a
smoothly varying range of colors. Clicking on any of these symbols
brings up a dialog window that allows you to change it.
Active Image: In GIMP , you
can work with many images at once, but at any given moment, only one
image is the “ active image ” . Here you find a small
iconic representation of the active image. Click the icon to display
a dialog with a list of the currently open images , click an
image in the dialog to make it active. Usually, you click an
image window in multi-window mode, or an image tab in single-window
mode, to make it the active image.
You can “ Drop to an XDS file manager to save
the image ” . XDS is an acronym for “ X
Direct Save Protocol ” : an additional feature for the X Window
System graphical user interface for Unix-like operating systems.
Note
At every start, GIMP selects a tool (the brush), a
color, a brush and a pattern by default, always the same. If you
want GIMP to select the
last tool, color, brush and pattern you used when quitting your
previous session, check the
Save input device settings on exit in
Preferences/Input
Devices .
Tip
The Toolbox window displays “ Wilber's eyes ” along the top
of the dialog. You can get rid of the “ Wilber's eyes ”
by adding the following line to your gimprc
file:
(toolbox-wilber no) .
It only affects the toolbox. The eyes in the Image window are only
visible when you do not have an open image.
Tip
Drag and drop an image from a file browser into the Toolbox window to open
the image in its own Image window or tab.
Chapter 3. First Steps with Wilber 2.2. Image Window
 Report an error in Bugzilla  12. Palettes 12. Palettes Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. Palettes
A palette is a set of discrete colors. In
GIMP , palettes are used mainly for two purposes:
They allow you to paint with a selected set of colors, in the same way
an oil painter works with colors from a limited number of tubes.
They form the colormaps of indexed images. An indexed image can use a
maximum of 256 different colors, but these can be any colors. The
colormap of an indexed image is called an "indexed palette" in
GIMP .
Actually neither of these functions fall very much into the mainstream of
GIMP usage: it is possible to do rather sophisticated
things in GIMP
without ever dealing with palettes. Still, they are something that an
advanced user should understand, and even a less advanced user may need to
think about them in some situations, as for example when working with GIF
files.
Figure 7.31. The Palettes dialog
When you install GIMP , it comes supplied with several
dozen predefined
palettes, and you can also create new ones. Some of the predefined
palettes are commonly useful, such as the “ Web ” palette,
which contains the set of colors considered “ web safe ” ;
many of the palettes seem to have been chosen more or less whimsically.
You can access all of the available palettes using the
Palettes dialog .
This is also the starting point if you want to create a new palette .
Figure 7.32. The Palette Editor
Double-clicking on a palette in the Palettes dialog brings up the
Palette Editor ,
showing the colors from the palette you clicked on. You can use this to
paint with the palette: clicking on a color sets GIMP 's
foreground to that
color, as shown in the Color Area of the Toolbox . Holding down the
Ctrl key while clicking, on the other hand, sets
GIMP 's
background color to the color you click on .
You can also, as the name implies, use the Palette Editor to change the
colors in a palette, so long as it is a palette that you have created
yourself . You cannot edit the palettes that are supplied with
GIMP ;
however you can duplicate them and then edit the copies.
When you create palettes using the Palette Editor, they are automatically
saved as soon as you exit GIMP , in the
palettes
folder of your personal GIMP directory . Any palette
files in this
directory, or in the system palettes
directory created when GIMP is installed, are
automatically loaded and
shown in the Palettes dialog the next time you start
GIMP . You can also
add other folders to the palette search path using the
Palette Folders
page of the Preferences dialog.
GIMP palettes are stored using a special file format,
in files with the
extension .gpl .
It is a very simple format, and they are ASCII files, so if you happen
to obtain palettes from another source, and would like to use them in
GIMP , it probably won't be very hard to convert them:
just take a look at
any .gpl and you will see what to do.
12.1. Colormap
Confusingly, GIMP makes use of two types of palettes.
The more
noticeable are the type shown in the Palettes dialog : palettes that
exist independently of any image. The second type,
indexed palettes ,
form the colormaps of indexed images. Each indexed image has its own
private indexed palette, defining the set of colors available in the
image: the maximum number of colors allowed in an indexed palette is
256. These palettes are called “ indexed ” because each
color is associated with an index number. (Actually, the colors in
ordinary palettes are numbered as well, but the numbers have no
functional significance.)
Figure 7.33. The Colormap dialog
The colormap of an indexed image is shown in the
Indexed Palette
dialog ,
which should not be confused with the Palettes dialog. The Palettes
dialog shows a list of all of the palettes available; the Colormap
dialog shows the colormap of the currently active image , if it is an
indexed image – otherwise it shows nothing.
You can, however, create an ordinary palette from the colors in an
indexed image—actually from the colors in any image. To do this,
choose Import Palette
from the right-click popup menu in the Palettes dialog: this pops up a
dialog that gives you several options, including the option to import
the palette from an image. (You can also import any of
GIMP 's gradients
as a palette.) This possibility becomes important if you want to create
a set of indexed images that all use the same set of colors.
When you convert an image into indexed mode , a major part of the process
is the creation of an indexed palette for the image. How this happens is
described in detail in Section 6.6, “Indexed mode” .
Briefly, you have several methods to choose from, one of which is to
use a specified palette from the Palettes dialog.
Thus, to sum up the foregoing, ordinary palettes can be turned into
indexed palettes when you convert an image into indexed mode ; indexed
palettes can be turned into ordinary palettes by importing them into the
Palettes dialog.
Figure 7.34. Colormap dialog (1) and Palette dialog (2) 11. Patterns 13. Presets
 Report an error in Bugzilla 
11. Patterns 11. Patterns Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. Patterns
A pattern is an image, usually small, used
for filling regions by tiling , that is, by
placing copies of the pattern side by side like ceramic tiles. A
pattern is said to be tileable if copies of
it can be adjoined left-edge-to-right-edge and
top-edge-to-bottom-edge without creating obvious seams. Not all
useful patterns are tileable, but tileable patterns are nicest for
many purposes. (A texture , by the way, is
the same thing as a pattern.)
Figure 7.27. Pattern usage
Three ways of using the “ Leopard ” pattern:
bucket-filling a selection, painting with the Clone tool , and
stroking an elliptical selection with the pattern.
In GIMP there are three main uses for patterns:
With the Bucket
Fill tool , you can choose to fill a region with a
pattern instead of a solid color.
Figure 7.28. The checked box for use a pattern
The box for pattern fill is checked and a click on the pattern
shows you all patterns in grid mode.
With the Clone tool,
you can paint using a pattern, with a wide variety of
paintbrush shapes.
When you stroke a path or selection, you
can do it with a pattern instead of a solid color. You can
also use the Clone tool as your choice if you stroke the
selection using a painting tool.
Tip
Note: Patterns do not need to be opaque. If you fill or paint using a
pattern with translucent or transparent areas, then the previous
contents of the area will show through from behind it. This is one of
many ways of doing “ overlays ” in GIMP.
When you install GIMP, it comes presupplied with a few dozen
patterns, which seem to have been chosen more or less randomly.
You can also add new patterns, either ones you create yourself, or
ones you download from the vast number available online.
GIMP's current pattern ,
used in most pattern- related operations, is shown in the
Brush/Pattern/Gradient area of the Toolbox. Clicking on the pattern symbol
brings up the Patterns dialog ,
which allows you to select a different pattern. You can also access the
Patterns dialog by menu, or dock it so that it is present continuously.
To add a new pattern to the collection, so that it shows up in the
Patterns dialog , you need to save it in a format GIMP can use , in a folder
included in GIMP's pattern search path. There are several file formats you
can use for patterns:
PAT
The .pat format is used for
patterns which were created specifically for GIMP. You can convert
any image into a .pat file by
opening it in GIMP and then saving it using a file name ending in
.pat .
Caution
Do not confuse GIMP -generated
.pat files with files
created by other programs (e.g.
Photoshop ) – after all,
.pat is just a part of an
(arbitrary) file name.
(However, GIMP does
support Photoshop
.pat files until a certain
version.)
PNG, JPEG, BMP, GIF, TIFF
Since GIMP 2.2 you can use
.png ,
.jpg ,
.bmp ,
.gif , or
.tiff files as patterns.
To make a pattern available, you place it in one of the folders in GIMP's
pattern search path. By default, the pattern search path includes two
folders , the system patterns folder, which you should
not use or alter, and the patterns
folder inside your personal GIMP directory . You can add new folders to the
pattern search path using the
Pattern Folders
page of the Preferences dialog. Any PAT file (or, in GIMP 2.2, any of the
other acceptable formats) included in a folder in the pattern search path
will show up in the Patterns dialog the next time you start GIMP .
There are countless ways of creating interesting patterns in GIMP, using
the wide variety of available tools and filters -- particularly the
rendering filters. You can find tutorials for this in many locations,
including the GIMP home page [ GIMP ] .
Some of the filters have options that allows you to make their results
tileable. Also, see Section 2.7, “Tileable Blur” , this
filter allows you to blend the edges of an image in order to make it more
smoothly tileable.
Figure 7.29. Pattern script examples
Examples of patterns created using six of the Pattern Script-Fu's
that come with GIMP. Default settings were used for everything
except size. (From left to right: 3D Truchet; Camouflage; Flatland;
Land; Render Map; Swirly)
Also of interest are a set of pattern-generating scripts that come with
GIMP : you can find them in the menu bar, through
File → Create → Patterns .
Each of the scripts creates a new image filled with a particular type of
pattern: a dialog pops up that allows you to set parameters controlling
the details of the appearance. Some of these patterns are most useful for
cutting and pasting; others serve best as
bumpmaps .
Figure 7.30. How to create new patterns 10. Gradients 12. Palettes
 Report an error in Bugzilla  2. Using Script-Fu Scripts 2. Using Script-Fu Scripts Chapter 13. Scripting  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Using Script-Fu Scripts 2. 1. Script-Fu?
Script-Fu is what the Windows world would call "macros" But Script-Fu is
more powerful than that. Script-Fu is based on an interpreting language
called Scheme, and works by using querying functions to the
GIMP
database. You can do all kinds of things with Script-Fu, but an ordinary
GIMP user will probably use it for automating things
that:
You want to do frequently. Are really complicated to do, and hard to remember.
Remember that you can do a whole lot with Script-Fu. The scripts that
come with GIMP can be quite useful, but they can also
serve as models
for learning Script-Fu, or at least as a framework and source of
modification when you make your own script. Read the Script-Fu Tutorial
in the next section if you want to learn more about how to make scripts.
We will describe some of the most useful scripts in this chapter, but we
won't cover them all. There are simply too many scripts. Some of the
scripts are also very simple and you will probably not need any
documentation to be able to use them.
Script-Fu (a dialect of Scheme) isn't the only scripting language
available for GIMP . But Script-Fu is the only
scripting language that is
installed by default. Other available scripting extensions are Perl and
Tcl. You can download and install both extensions at the
GIMP Plugin
Registry [ GIMP-REGISTRY ] .
Chapter 13. Scripting 2.2. Installing Script-Fus  Report an error in Bugzilla  2. Starting GIMP the first time 2. Starting GIMP the first time Chapter 2. Fire up the GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Starting GIMP the first time
When first run, GIMP performs a series of steps to
configure options and directories. The configuration process creates a
subdirectory in your home directory called
.gimp-2.8 . All of the
configuration information is stored in this directory. If you remove
or rename the directory, GIMP will repeat the initial
configuration process, creating a new
.gimp-2.8
directory. Use this capability to explore different configuration
options without destroying your existing installation, or to recover if
your configuration files are damaged.
2.1. Finally . . .
Just a couple of suggestions before you start, though:
First, GIMP provides tips you can read at any time
using the menu command
Help → Tip of the Day .
The tips provide information that is considered useful, but not easy to
learn by experimenting; so they are worth reading. Please read the tips
when you have the time .
Second, if at some point you are trying to do something, and
GIMP
seems to have suddenly stopped functioning, the section
Getting Unstuck
may help you out. Happy Gimping!
Chapter 2. Fire up the GIMP Chapter 3. First Steps with Wilber  Report an error in Bugzilla  5. Creating Shortcuts to Menu Functions 5. Creating Shortcuts to Menu Functions Chapter 12. Enrich my GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. Creating Shortcuts to Menu Functions
Many functions which are accessible via the image menu have a default
keyboard shortcut. You may want to create a new shortcut for a command
that you use a lot and doesn't have one or, more rarely, edit an existing
shortcut. There are two methods for doing this.
Procedure 12.1. Using dynamic keyboard shortcuts
First, you have to activate this capability by checking the
Use dynamic keyboard shortcuts option in
the Interface item of the
Preferences menu. This
option is usually not checked, to prevent accidental key presses
from creating an unwanted shortcut.
While you're doing that, also check the Save keyboard
shortcuts on exit option so that your shortcut will
be saved.
To create a keyboard shortcut, simply place the mouse pointer on a
command in the menu: it will then be highlighted. Be careful that the
mouse pointer doesn't move and type a sequence of three keys, keeping
the keys pressed. You will see this sequence appear on the right of
the command.
It is best to use the
Ctrl + Alt + Key
sequence for your custom shortcuts.
Figure 12.31. Configure Keyboard Shortcuts Procedure 12.2. Using the Keyboard Shortcut Editor
You get to this Editor by clicking on Configure
keyboard shortcuts in the “ Interface ”
item of the Preferences menu.
As shown in this dialog, you can select the command you want to
create a shortcut for, in the “ Action ” area. Then you
type your key sequence as above. In principle, the Space bar should
clear a shortcut. (In practice, it clears it, but doesn't delete it.)
This shortcut editor also allows you to control the
tool parameter settings with the keyboard. At the top
of this dialog, you can find a Context menu
that takes you to the tool parameters. To make your work easier,
tool types are marked with small icons.
Note
Custom Keyboard shortcuts are stored in one of Gimp's hidden
directory ( /home/[username]/.gimp-2.8/menurc )
under Linux, and
C:\Documents and Settings\[Username]\.gimp-2.8\menurc
under Windows XP. It is a simple text file that you can transport from
one computer to another.
4. How to Set Your Tile Cache 6. Customize Splash- Screen
 Report an error in Bugzilla  3. Undoing 3. Undoing Chapter 3. First Steps with Wilber  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Undoing
Almost anything you do to an image in GIMP can be
undone. You can undo the most recent action by choosing
Edit → Undo
from the image menu, but this is done so frequently that you
really should memorize the keyboard shortcut,
Ctrl + Z .
Undoing can itself be undone. After having undone an action, you
can redo it by choosing
Edit → Redo
from the image menu, or use the keyboard shortcut,
Ctrl + Y .
It is often helpful to judge the effect of an action by repeatedly
undoing and redoing it. This is usually very quick, and does not
consume any extra resources or alter the undo history, so there is
never any harm in it.
Caution
If you undo one or more actions and then operate on the image in any way
except by using Undo or Redo, it will no longer be possible to redo
those actions: they are lost forever. The solution to this, if it
creates a problem for you, is to duplicate the image and then test on
the copy. ( Do Not test the original, because the
undo/redo
history is not copied when you duplicate an image.)
If you often find yourself undoing and redoing many steps at a time, it
may be more convenient to work with the
Undo History dialog ,
a dockable dialog that shows you a small sketch of each point in the
Undo History , allowing you to go back or forward to that point by
clicking.
Undo is performed on an image-specific basis : the "Undo History" is one of
the components of an image. GIMP allocates a certain
amount of memory to
each image for this purpose. You can customize your Preferences to
increase or decrease the amount, using the
Environment
page of the Preferences dialog. There are two important variables: the
minimal number of undo levels ,
which GIMP will maintain regardless of how much memory
they consume, and
the maximum undo memory , beyond which
GIMP will
begin to delete the oldest items from the Undo History.
Note
Even though the Undo History is a component of an image, it is not saved
when you save the image using GIMP 's native XCF
format , which preserves
every other image property. When the image is reopened, it will have an
empty Undo History.
GIMP 's implementation of Undo is rather sophisticated.
Many
operations require very little Undo memory (e.g., changing visibility of a
layer), so you can perform long sequences of them before they drop out of
the Undo History. Some operations, such as changing layer visibility,
are compressed ,
so that doing them several times in a row produces only a single point
in the Undo History . However, there are other operations that may consume
a lot of undo memory. Most filters are implemented by plug-ins , so the
GIMP core has no efficient way of
knowing what changed. As such, there is no way to implement Undo except
by memorizing the entire contents of the affected layer before and after
the operation. You might only be able to perform a few such operations
before they drop out of the Undo History.
3.1. Things That Cannot be Undone
Most actions that alter an image can be undone . Actions that do not
alter the image generally cannot be undone. Examples include
saving the image to a file, duplicating the image, copying part of the
image to the clipboard, etc. It also includes most actions that affect
the image display without altering the underlying image data. The most
important example is zooming. There are, however, exceptions: toggling
QuickMask on or off can be undone, even though it does not alter the
image data .
There are a few important actions that do alter an image but
cannot be undone:
Closing the image
The Undo History is a component of the image, so when the image is
closed and all of its resources are freed, the Undo History is
gone. Because of this, unless the image has not been modified
since the last time it was saved , GIMP always
asks you to confirm that you really want to close the image .
(You can disable this in the
Environment
page of the Preferences dialog; if you do, you are assuming
responsibility for thinking about what you are doing .)
Reverting the image “ Reverting ”
means reloading the image from the file.
GIMP actually implements this
by closing the image and creating a new image, so the Undo History
is lost as a consequence. Because of this, if the image is
unclean, GIMP asks you to confirm that
you really want to revert the image.
“ Pieces ” of actions
Some tools require you to perform a complex series of
manipulations before they take effect, but only allow you to undo
the whole thing rather than the individual elements. For example,
the Intelligent Scissors require you to create a closed path by
clicking at multiple points in the image, and then clicking inside
the path to create a selection. You cannot undo the individual
clicks: undoing after you are finished takes you all the way back
to the starting point. For another example, when you are working
with the Text tool, you cannot undo individual letters, font
changes, etc.: undoing after you are finished removes the newly
created text layer.
Filters, and other actions performed by plugins or scripts, can be
undone just like actions implemented by the GIMP
core, but this requires
them to make correct use of GIMP 's Undo functions. If
the code is not
correct, a plugin can potentially corrupt the Undo History, so that not
only the plugin but also previous actions can no longer properly be
undone. The plugins and scripts distributed with GIMP
are all believed
to be set up correctly, but obviously no guarantees can be given for
plugins you obtain from other sources. Also, even if the code is
correct, canceling a plugin while it is running may corrupt the
Undo History, so it is best to avoid this unless you have
accidentally done something whose consequences are going to be very
harmful.
2.3. Dialogs and Docking 4. Common Tasks
 Report an error in Bugzilla  8. 5. Use GEGL 8. 5. Use GEGL 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Report an error in Bugzilla 
5. 3. Device Status Dialog 5.3. Device Status Dialog 5. Misc. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 3. Device Status Dialog Figure 15.74. The “ Device Status ” Dialog
This window gathers together the current options of Toolbox, for each
of your input devices: the mouse (named “ Core pointer ” ) or
either the tablet, if you have one. These options are represented by
icons: foreground and background colors, brush, pattern and
gradient. Excepted for colors, clicking on an icon opens the window
which lets you select another option; the tool-box will be updated when
changing. You can drag and drop items to this dialog.
The “ Save device status ” button
at the bottom of the
window , seems to have the same action as the “ Record device
status now ” option in the Input Devices section in preferences.
 5. 3. 1. Activating the Dialog
The device status dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking”
for help on manipulating it. It can be activated in two ways:
From an image menu :
Windows → Dockable Dialogs → Device Status .
From the Tab menu in any dialog :
Add a Dock → Device Status  5. 2. Tool Preset Editor 5. 4. Error Console
 Report an error in Bugzilla  3. Image-content Related Dialogs 3. Image-content Related Dialogs Chapter 15. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Image-content Related Dialogs 3. 1. FG/BG Color Dialog Figure 15.23. The FG/BG Color dialog
The Color dialog lets you manage and pick up new colors. You can use it
into five different modes: GIMP, CMYK, Triangle, Watercolor and Scales. It
has an interesting eyedropper to pick up a color anywhere on your screen.
The dialog called from the FG/BG area in the toolbox is a bit different
compared to the one called from the image menu:
the sliders are permanently visible instead of selected from the
scale menu,
twelve buttons show the last used colors. You may choose
a color by clicking on one of these buttons or add the current FG
or BG color to this history list.
This dialog works either on the foreground or the background color.
 3. 1. 1. Activating the Dialog
The “ Colors ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from an image menu:
Windows → Dockable Dialogs → Colors ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Colors ,
from the toolbox: click on the current Foreground or Background
color. 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Colors ” dialog from the image-menu:
Windows → Colors .
3.1.2. Using the “ FG/BG color ” dialog GIMP Selector
With the GIMP Color Selector, you select a color by clicking on a
one-dimensional strip located at the right edge, and then in a
two-dimensional area located on the left. The one-dimensional
strip can encode any of the color parameters H, S, V, R, G, or B,
as determined by which of the adjoining buttons is pressed. The
two-dimensional area then encodes the two complementary color
parameters.
CMYK Figure 15.24. CMYK
You get to this selector by clicking on the printer icon. The CMYK
view gives you the possibility to manage colors from the
CMYK
color model.
Triangle Figure 15.25. The triangle selector
This selector uses the HSV color
model. Click in the chromatic circle and drag
the mouse pointer to select the Hue. Click-and-drag in the
triangle to vary intuitively Saturation
(vertically) and Value (horizontally).
Watercolor Figure 15.26. Watercolor Color Selector
This color selector is symbolized by a brush. The function mode of
this selector is a little different from that of models
presented so far. The principle consists in changing the
current foreground color by clicking in the rectangular
palette. If the current foreground color is for example
white, then it turns to reddish by clicking in the red
color area. Repeated clicking strengthens the effect. With the
slider, which is right apart from the color palette, you
can set the color quantity per every mouse click. The higher the
sliding control is, the more color is taken up per click.
Palette Figure 15.27. Palette Color Selector
This color selector brings up a list of the colors of the current
palette in the
Palettes dialog .
You can set GIMP 's foreground or background
colors by clicking on colors in the colors display. You can also
use the arrow keys to move within the list of colors.
Scales Figure 15.28. The Scales selector
This selector displays a global view of R, G, B channels and H, S,
V values, placed in sliders.
Color picker
The color picker has a completely different behavior, than the
color picker tool .
Instead of picking the colors from the active image, you're able
to pick colors from the entire screen.
HTML Notation
See HTML notation .
You can also use the CSS keywords; enter the first letter of a
color to get a list of colors with their keyword :
Figure 15.29. CSS keywords example
Right-clicking in the HTML Notation text box opens a context
menu that allows you to edit your notation, particularly to
paste a complex notation you have copied elsewhere. This menu
leads to various Input Methods that allow
you to use foreign characters, and to the possibility to
Insert Unicode Control Characters . This is
a vast field, beyond this help. Please see
[ UNICODE ] .
Figure 15.30. The HTML Notation context menu
Right up you find a symbol, consisting of two arrows, with which you can
exchange the foreground and background color. At the bottom left of the
dialog, just below the foreground color block, you find a switching
surface with two small, one black and the other white, partially
overlapping squares. If you click on these, the front and background
color are put back to black and white respectively. 2.7. Undo History Dialog 3.2. Brushes Dialog
 Report an error in Bugzilla  4. Image Management Related Dialogs 4. Image Management Related Dialogs Chapter 15. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. Image Management Related Dialogs 4. 1. Buffers Dialog Figure 15.63. The Buffers dialog (as a list)
Buffers are temporary repositories for image data, created when
you cut or copy part of a drawable (a layer, layer mask, etc.).
You can save a document in this buffer in two ways:
Edit → Buffer → Copy Named
or
Edit → Buffer → Cut Named
A dialog pops up asking you to name a buffer to store the data
in. There is no hard limit on the number of named buffers you
can create, although, of course, each one consumes a share of memory.
The “ Buffers ” dialog shows you the contents of all existing
named buffers, and allows you to operate on them in several ways. It
also shows you, at the top, the contents of the Global Buffer, but this
is merely a display: you can't do anything with it.
Caution
Named buffers are not saved across sessions. The only way to save their
contents is to paste them into images.
 4.1.1. Activating the Dialog
This dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from an image menu:
Windows → Dockable Dialogs → Buffers ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Buffers . 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Buffers ” dialog from the image-menu:
Windows → Buffers .
4.1.2. Using the Buffers dialog Figure 15.64. The Buffers Menu
Clicking on a buffer in the display area makes it the active buffer, i.
e., the one that will be used for paste commands executed with the
Buffers Menu or the buttons at the bottom of the dialog . Double-clicking
on a buffer causes its contents to be pasted to the active image as a
floating selection ; this is a quick way of executing the “ Paste
Buffer ” command.
At the bottom of the dialog are four buttons. The operations they
perform can also be accessed from the Buffers Menu that you get by right
clicking on the active buffer.
Figure 15.65. The Buffers dialog (Grid View)
In the Tab menu for the “ Buffers ” dialog , you can choose
between View as Grid and
View as List .
In Grid mode, the buffers are laid out in a rectangular array .
In List mode, they are lined up vertically, with each row showing
a thumbnail of the contents of the buffer, its name, and its pixel
dimensions.
Tip Ctrl + F
opens a search field.
See View as List; View as Grid You can change the size of the buffer previews in the dialog using
the “ Preview Size ” submenu of the dialog's Tab menu.
4.1.2.1. Buttons at the bottom
At the bottom of the dialog you find a couple of buttons:
Paste Buffer
This command pastes the contents of the selected buffer into the
active image , as a floating selection . The only difference
between this and the ordinary
Paste command is that it uses the selected buffer rather than the
global clipboard buffer.
Paste Buffer Into
This command pastes the contents of the selected buffer into
the active image 's selection, as a floating selection. The
only difference between this and the ordinary
Paste Into command is
that it uses the selected buffer rather than the global
clipboard buffer.
Paste Buffer as New
This command creates a new single-layer image out of the
contents of the selected buffer. The only difference between
this and the ordinary
Paste as New command
is that it uses the selected buffer rather than the content
of the global clipboard buffer.
Delete Buffer
This command deletes the selected named buffer, no questions
asked. You cannot delete the Global Buffer.
4.1.2.2. Context menu Figure 15.66. The “ Buffers ” context menu
These commands are explained above with Buttons.
3.7. Fonts Dialog 4.2. Images Dialog
 Report an error in Bugzilla  5. Misc. Dialogs 5. Misc. Dialogs Chapter 15. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. Misc. Dialogs 5. 1. Tool Presets Dialog
In GIMP -2.6, tool presets were not easy to use. You had
to click on a tool first, and then click on the Restore
Presets... button in the button bar at the bottom of the Tool
options dialog ... if you had not disabled this button bar in the Tab menu
to make place on your desk! Now, with GIMP -2.8, a
dockable Tool Presets Dialog is available where you just have to click on a
preset to open the corresponding tool with its saved options.
Figure 15.72. The Tool Presets Dialog  5. 1. 1. Activating the Dialog
The “ Tool Presets Dialog ” is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from an image menu:
Windows → Dockable Dialogs → Tool Presets ;
or, as a tab in Toolbox window, through
Tab Menu → Add Tab → Tool Presets . 
5. 1.2. Using the Tool Presets Dialog
This dialog comes with a list of predefined presets. Each of them has an
icon representing the tool presets will be applied to and a name.
Presets can be tagged so that you can arrange presets display as
you want. Please see Section 3.6, “Tagging” for more information
about tagging.
Double-clicking on a preset icon opens the Tool Preset Editor .
Double-clicking on preset name allows you to edit this name.
At the bottom of the dialog appear four buttons:
Edit this tool preset : clicking on this button
opens the Tool Preset Editor for the selected preset. You can
actually edit presets you have created ; predefined presets options
are all grayed out and inactive. But you can create a new preset
from a predefined preset and edit its options.
The Tool Preset Editor is described in
Section 5 .2, “Tool Preset Editor” .
Create a new tool preset : before clicking on
this button, you can either select an existing preset, or select a
tool in Toolbox, for example the Healing Tool which is not in the
presets list. A new preset is created at the top of the dialog and
the Tool Preset Editor is opened. Please see
Section 5.2, “Tool Preset Editor” .
Delete this tool preset : this button is active
only for presets you have created.
Refresh tool presets : If you have added a
preset manually in gimp/2.0/tool-presets folder, you have to click
on this button to include it in the presets list.
Note
With GIMP -2.8, tool presets are saved in a new
format (.gtp). To use your 2.6 presets, you have to convert them
using
http://wiki.gimp.org/index.php/Mindstorm:Preset_converter ,
until it is included in GIMP.
5.1.3. The Tool Presets Dialog Context Menu
Right-clicking on the Presets Dialog opens a context menu where you find
some commands already described with buttons: Edit tool preset, New tool
preset, Refresh tool presets. You also find two new commands:
Duplicate Tool Preset : this command is always
disabled. It is not necessary since, as we saw above, a duplicate
is automatically created when you create a new preset from an
existing preset.
Copy Tool Preset Location : this command copies
the path to the tool preset file into clipboard.
4.4. Templates Dialog 5.2. Tool Preset Editor  Report an error in Bugzilla  2. Image Structure Related Dialogs 2. Image Structure Related Dialogs Chapter 15. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Image Structure Related Dialogs
The following dialogs let you control and manipulate image structures,
such as layers ,
channels , or
paths .
2.1. Layers Dialog Figure 15.1. Layers Dialog
The “ Layers ” dialog is the main interface to edit, modify
and manage your layers. You can think of layers as a stack of slides or
clothes on your body. Using layers, you can construct an image of several
conceptual parts, each of which can be manipulated without affecting any
other part of the image. Layers are stacked on top of each other. The
bottom layer is the background of the image, and the components in the
foreground of the image come above it.
Figure 15.2. An image with layers Layers of the image Resulting image  2. 1. 1. Activating the dialog
The “ Layers ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking”
for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Layers ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Layers ,
from the (default) shortcut:
Ctrl + L . 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Layers ” dialog from the image-menu:
Windows → Layers .
2.1.2. Using the Layer dialog Overview
Every layer appears in the dialog in the form of a thumbnail. When
an image has multiple layers as components, they appear as a list.
The upper layer in the list is the first one visible, and the
lowest layer the last visible, the background. Above the list one
can find characteristics related individually to each layer. Under
the list one can find management buttons for the layer list. A
right-click in a layer thumbnail opens the Layer
context menu .
Layer attributes
Every layer is shown in the list along with its attributes:
Layer visibility
In front of the thumbnail is an icon showing an eye. By
clicking on the eye , you toggle whether the layer is visible
or not. ( Shift -clicking on the eye causes
all other to be hidden.)
Chain layers
Another icon, showing a chain, allows you to group layers
for operations on more than one layer at a time ( for example
with the Move tool ).
Layer thumbnail
The layer content is represented in a thumbnail. Maintaining
left-click for a second on this thumbnail makes it larger.
When the layer is active, the thumbnail has a white border.
The border is black if the layer is inactive.
When the layer has a mask, the inactive element takes a black
border.
Layer name
The main attribute is the name of the layer . You can edit
this by a double-click on the name of the layer . You can
also use the “ Edit Layer Attributes ” dialog you
get by double-clicking on the thumbnail (or the mask), or
through right-click on the layer and select “ Edit Layer
Attributes... ” .
Note
In the case of an animation layer (GIF or MNG), the name of the
layer can be used to specify certain parameters : Layer_name
(delay in ms) (combination mode), for example Frame-1 (100 ms)
(replace). The delay
sets the time during which the layer is visible in the
animation. The combination mode sets whether you combine the
layer with the previous layer or replace it: the two modes are
(combine) or (replace).
Layers characteristics
Above the layer list, it is possible to specify some properties
for the active layer. The active layer is the one highlighted in
blue. The properties are: “ Layer mode ” ,
“ Opacity ” , “ Lock pixels ” and
“ Lock Alpha channel ” .
Mode
The layer mode determines how the layer interacts with the
other layers. From the combo box you can access all the
modes provided by GIMP. The layer modes are fully detailed
in Section 2, “Layer Modes” .
Opacity
By moving the slider you give more or less opacity to the
layer. With a 0 opacity value, the layer is transparent and
completely invisible. Don't confuse this with a Layer Mask,
which sets the transparency pixel by pixel.
Lock
You have two possibilities:
Lock pixels : when this
option is checked , you can't modify layer pixels. This
may be necessary to protect them from unwanted changes.
Lock alpha channel : if
you check this option the transparent areas of the layer
will be kept, even if you have checked the
Fill transparent areas
option for the Bucket fill tool.
Figure 15.3. Example for Locking Alpha Channel
The active layer has three horizontal, opaque, green
stripes on a transparent background. We paint a
vertical red stripe. “ Lock ” unchecked:
Opaque and transparent areas of the active layer are
painted with red.
“ Lock ” checked: Only opaque
areas of the active layer are painted with red.
Transparent areas are preserved.
Tip
If a layer name in the Layer Dialog is in bold, then this
layer has no Alpha channel .
Layer management
Under the layer list a set of buttons allows you to perform some
basic operations on the layer list.
New layer
Here you can create a new layer. A dialog is opened where
you can enter the Layer name ,
perhaps change the default Height
and Width , and choose the
Layer fill type
that will be the new layer's background.
Raise layer
Here you can move the layer up a level in the list. Press
the Shift
key to move the layer to the top of the list .
Lower layer
Here you can move the layer down a level in the list. Press
the Shift
key to move the layer to the bottom of the list .
Tip
To move a layer at the bottom of the list , it may first be
necessary to add a transparency channel (also called Alpha
channel) to the Background layer. To do this, right click
on the Background layer and select
Add Alpha channel from the menu.
Duplicate layer
Here you can create a copy of the active layer . Name of new
layer is suffixed with a number.
Anchor layer
When the active layer is a temporary layer (also called
floating selection) shown by this icon
,
this button anchors it to the previous active layer.
Delete layer Here you can delete the active layer. More layer functions
Other functions about layer size are
available in the Layer
Drop down menu you get by right clicking on the
Layer Dialog. You can find them also in the Layer sub-menu
of the image menu.
You will find merging layers functions
in the Image menu .
Clicking-and-dragging layers
Click and hold on layer thumbnail: it enlarges and you can
move it by dragging the mouse.
So you can put this layer down
somewhere else in the layer list .
You can also
put the layer down into Toolbox :
a new image is created that contains this layer only.
Finally, you can
put the layer down into another image :
this layer will be added to the layer list, above existing
layers.
2.1.3. Layer masks Figure 15.4. “ Add mask ” dialog Overview
A transparency mask can be added to each layer, it's called Layer
mask. A layer mask has the same size and same number of pixels as
the layer to which it is attached. Every pixel of the mask can then
be coupled with a pixel at the same location in the layer . The mask
is a set of pixels in gray-tone on a value scale from 0 to 255. The
pixels with a value 0 are black and give a full transparency to the
coupled pixel in the layer. The pixels with a value 255 are white
and give a full opacity to the coupled pixel in the layer.
To create a layer mask start with a right click on the layer to call
the context menu and select Add layer mask
in the menu. A dialog appears where you can initialize the content of
the mask:
White (full opacity) :
the mask is white
in the Layer Dialog. So, all pixels of the layer are visible
in the image window since painting the mask with white makes
layer pixels fully visible. You will paint with black to make
layer pixels transparent.
Black (full transparency) : the mask is
black in the Layer Dialog. So, the layer is fully transparent
since painting the mask with black makes layer pixels
transparent. Painting with white will remove the mask and make
layer pixels visible.
Layer's alpha channel : the mask is
initialized according to the content of layer Alpha
channel. If the layer still contains transparency it's
copied in the mask.
Transfer layer's alpha channel :
Does the same thing as the previous option, except that it
also resets the layer's alpha channel to full opacity .
Selection : the mask is initialized
according to pixel values found in the selection.
Grayscale copy of layer : the mask
is initialized according to pixel values of the layer.
Channel : The layer mask is initialized
with a selection mask you have created before, stored in the
Channel dialog.
Invert mask : This checkbox allows you to
invert : black turns to white and white turns to black.
When the mask is created it appears as a thumbnail right to the
layer thumbnail. By clicking alternatively on the layer and mask
thumbnail you can enable one or other. The active item has a white
border (which is not well visible around a white mask). That's an
important point. Always keep the Layers Dialog prominently when
working with masks, because you can't see, looking at the canvas,
which of the layer or the mask is active.
Pressing Alt (or
Ctrl + Alt and
click on the layer mask thumbnail) is equivalent to the
Show Layer Mask
command : the layer mask border turns to green. If you press
Ctrl the border is red and the result is
equivalent to the
Disable Layer Mask
command . To return to normal view redo last operation. These
options are for greater convenience in your work.
Layer Mask example Figure 15.5. A layer with layer mask
This image has a background layer with a flower and another
blue one, fully opaque. A white layer mask has been added to
the blue layer. In the image window, the blue layer remains
visible because a white mask makes layer pixels visible.
Figure 15.6. Painting the layer mask
The layer mask is active. You paint with black color, which
makes the layer transparent: the underlying layer becomes
visible.
Chapter 15. Dialogs 2.2. Channels Dialog
 Report an error in Bugzilla  5. 8. Display Filters 5. 8. Display Filters 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 8. Display Filters
This command shows a dialog window when executed. This window can be used
to manage the display filters and their options. Display filters are not
to be confused with the filters in the filters -menu .
Display filters do not alter the image data , but only one display of it.
You can imagine display filters like big panes before your screen. They
change your perception of the image. This can be useful for things like
soft proofing prints, controlling the color management but also simulation
of color deficient vision.
 5.8. 1. Activating the Command
You can access this command from the image menubar through
View → Display Filters… .  5. 8. 2. Description of the “ Display Filters ” Dialog Figure 16.43.
The “ Configure Color Display Filters ” dialog
This dialog has two small selectboxes. The left selectbox displays the
Available Filters . You can move a filter to the
right selectbox by selecting it and clicking on the
right arrow button. The
Active Filters window on the right displays
filters you have chosen and which will be applied if the adjacent box
is checked. You can move filters from the right selectbox to the left
selectbox by using the left arrow button. If you
select a filter by clicking on its name, its options are displayed
below the two selectboxes, in the
Configure Selected Filter area.
Simulation of deficient vision
( Section 5.8.3, “Color Deficient Vision” ;
Section 5.8.5, “Contrast” )
Color Management
( Section 5.8.6, “Color Management” ;
Section 5.8.7, “Color Proof” )
Others ( Section 5.8.4, “Gamma” )
5.8.3. Color Deficient Vision
The images you create, we hope, will be seen by many people on many
different systems. The image which looks so wonderful on your screen may
look somewhat different to people with sight deficiencies or on a screen
with different settings from yours. Some information might not even be
visible.
Figure 16.44.
Description of the “ Color Deficient Vision ” dialog
5.8.3.1. Options Color Deficiency Type
In this drop-down menu you can select from among:
Protanopia [11] (insensitivity to red)
Protanopia is a visual deficiency of the color red. It's
the well-known daltonism (red-green color blindness).
Daltonism occurs fairly frequently in the population.
Protanopia is actually more complex than this; a person
with this problem cannot see either red or green, although
he is still sensitive to yellow and blue. In addition, he
has a loss of luminance perception and the hues shift
toward the short wavelengths.
Deuteranopia (insensivity to green)
With deuteranopia, the person has a deficiency in green
vision. Deuteranopia is actually like protanopia, because
the person has a loss of red and green perception, but he
has no luminance loss or hue shift.
Tritanopia (insensitivity to blue)
With tritanopia, the person is deficient in blue and
yellow perception, although he is still sensitive to red
and green. He lacks some perception of luminance, and the
hues shift toward the long wavelengths.
5.8.3.2. Examples Figure 16.45. Example of protanopia Original image
A red-blind person cannot see the red (255,0,0) text on a black
(0,0,0) background.
Figure 16.46.
Examples of the three types of vision deficiencies in one image
Normal vision Protanopia
Deuteranopia; in deuteranopia, yellow is shifted toward red.
Tritanopia; in tritanopia, green is slightly represented in the
blue range.
5.8.4. Gamma
Figure 16.47. The “ Gamma ” dialog
The correspondence between electrical intensity and color brightness
is not exact and it depends upon the device (the camera, the scanner,
the monitor, etc.). “ Gamma ” is a coefficient used to
correct this correspondence. Your image must be visible in both dark
and bright areas, even if it is displayed on a monitor with too much
luminence or not enough. The “ Gamma ” Display Filter
allows you to get an idea of the appearance of your image under these
conditions.
Tip
In case you want not only to change the gamma of the current display,
but the change the gamma within the image itself, you can find a
description in Section 5.7, “Levels” .
5.8.5. Contrast
Figure 16.48. The “ Contrast ” dialog
Here, we are back in the medical domain.
“ Contrast Sensitivity ”
is the capacity of the visual system to distinguish slight differences
in contrast. Some people with cataracts (which means that the lens has
opaque crystals that scatter light over the retina) or retinal disease
(for instance, due to diabetes, which destroys the rods and cones) have
a deficiency in sensitivity to contrast: for example, they would have
difficulties distinguishing spots on a dress.
If you are interested in this subject, you can browse the Web for
“ contrast sensitivity ” .
5.8.5.1. Options Contrast Cycles
With the “ Contrast ”
Filter, you can see the image as if you were suffering from
cataracts. You may have to increase the contrast of the image so
that your grandmother can see it well. In most cases, only very
low values of the Contrast Cycles
parameter are of interest. Higher values create a side-effect
which doesn't interest us here: if you increase the luminosity
value above 255, the complementary color appears.
5.8.6. Color Management Figure 16.49. The “ Color Management ” dialog
This filter allows to enable the GIMP color management for each image
window. To learn more about the color management in GIMP , please read
Section 1, “Color Management in GIMP” .
5.8.6.1. Options
All the customizing for the color management in GIMP has to be done
in the GIMP preferences. You can find detailed information about
this in Section 1.14, “Color Management” .
5.8.7. Color Proof
The various systems for reproducing colors cannot represent the
infinity of colors available. Even if there are many colors in
common between the various systems and nature, some of the colors
will not be the same. The “ gamut ” is the color range of
a system. Color Profiles allow you to compensate
for these differences.
Before you print an image, it may be useful for you to see if you
will get the result you want by applying a profile. The “ Color
Proof ” filter shows you how your image will look after a color
profile has been applied.
Figure 16.50. The “ Color Proof ” dialog 5.8.7.1. The “ Color Proof ” options Profile
This option allows to select a color profile that is used to
simulate the color abilities of the printer. If the desired
profile is not shown in the list you might want to add it by
selecting a file. This can be done by selecting the last entry
of the list.
Intent
With this option you can select the rendering intent, which is
the method used to determine how colors that can't be reproduced
by a device ( “ are out of gamut ” ) should be handled.
The different rendering intents are described in detail in the
glossary Rendering Intent .
Black Point Compensation
Black point compensation allows a better representaion of
dark colors of your image when printing.
[11]
Greek:
proto : first (color in
the RGB Color
System ):
an : negation;
op : eye, vision.
5.7. Navigation Window 5. 9. Show Selection
 Report an error in Bugzilla  4. 3. Document History Dialog 4.3. Document History Dialog 4. Image Management Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 3. Document History Dialog Figure 15.68. Document History dialog
The History Dialog displays the list of the documents you have opened in
previous sessions. It is more complete than the list you get with the
“ Open Recent ” command.
 4.3. 1. Activating the Dialog
The “ History ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
From an image menu:
Windows → Dockable Dialogs → Document History .
From the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Document History .
From the image Menu bar through:
File → Open Recent → Document History .  4. 3.2. Using the Document History dialog
The scroll bar allows you to browse all images you have opened before.
In the Tab menu for the “ Document History ” dialog, you can
choose between View as Grid and
View as List .
In Grid mode, the documents are laid out in a rectangular array .
In List mode, they are lined up vertically, with each row showing
a thumbnail of the contents of the image, its name, and its pixel
dimensions.
Tip Ctrl + F
opens a search field.
See View as List; View as Grid Use the Open the selected entry
button or Open Image command of the dialog's
context menu , to open the image you have selected. With the
Shift key pressed, it raises an image hidden behind
others. With the Ctrl key pressed , it opens the Open
Image dialog.
Use the Remove the selected entry
button or Remove Entry command of the dialog's
context menu , to remove an image from the History dialog. The image
is removed from the recently open images list also. But the image itself
is not deleted.
Use the Clear the entire file history
button or Clear History command of the
dialog's context menu , to remove all the files from the history.
Use the Recreate Preview
button or Recreate Preview command of the
dialog's context menu , to update preview in case of change.
With Shift key pressed, it acts on all previews.
With Ctrl key pressed, previews that
correspond to files that can't be found out, are deleted.
4.2. Images Dialog 4.4. Templates Dialog
 Report an error in Bugzilla  3. 12. Buffer 3.12. Buffer 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 12. Buffer Figure 16.19.
The “ Buffer ” submenu of the “ Edit ” menu
The commands in this submenu operate on
named buffers . You can use the
Buffers dialog
to view and manage any named buffers you have created.
 3.12. 1. Activate the Submenu
You can access this submenu from the image menubar through
Edit → Buffer .  3.12.2. Sub-menu entries  Cut Named
The Cut Named command cuts the
content of the selection from the active layer in the usual way,
but instead of storing the contents in the global clipboard, it
stores it in a special buffer that you name using a pop-up
dialog.   Copy Named
The Copy Named command copies the
contents of the selection from the active layer in the usual way,
but instead of storing the content in the global clipboard, it
stores it in a special buffer that you name using a pop-up
dialog.  Copy Visible Named
 The Copy Visible Named command copies
the content of the selection from all the visible layers in the
usual way, but instead of storing the content in the global
clipboard, it stores it in a special buffer that you name using a
pop-up dialog.  Paste Named
The Paste Named
command simply brings up the
Buffers dialog .
By selecting one of the listed buffers, and pressing one of the
buttons at the bottom , you can either
Paste Buffer ,
Paste Buffer Into ,
or Paste Buffer as
New .
3.11. Paste as 3.13. Clear
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3. 13. Clear 3. 13. Clear 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 13. Clear
The Clear command deletes everything
in the current selection. If there is no current selection,
the contents of the active layer are removed. If the active
layer has an alpha channel , the deleted selection is made
transparent. You can restore the original color to the transparent
area using the Eraser tool, by setting it to Anti-Erase. If the
layer does not have an alpha channel , the deleted area is
filled using the current background color.
Clearing a selection does not delete the selection itself. Unlike
“ Cut ” , “ Clear ” does not place the deleted
contents in the Clipboard and the contents of the clipboard are
unaffected.
 3. 13. 1. Activate the Command
You can access this command from the image menubar through
Edit → Clear ,  or by using the keyboard shortcut Delete .
3.12. Buffer 3.14. Fill with FG Color
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3. 8. Copy Visible 3.8. Copy Visible 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 8. Copy Visible
The Copy Visible command is similar to the
Copy command. However, it does
not just copy the contents of the current layer; it copies the contents
of the visible layers (or the selection of the visible layers), that
is, the ones that are marked with an “ eye ” .
Note
Please note that the information about the layers is lost when the
image data is put in the clipboard. When you later paste the
clipboard contents, there is only one layer , which is the fusion of
all the marked layers.
 3. 8. 1. Activating the Command
You can access this command from the image menubar through
Edit → Copy Visible .  3. 7. Copy 3. 9. Paste
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3. 7. Copy 3. 7. Copy 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 7. Copy
The Copy command makes
a copy of the current selection and stores it in the Clipboard. The
information can be recalled using the
Paste ,
Paste Into , or
Paste As New commands. If
there is no selection , the entire current layer is
copied. “ Copy ” only works on the current active
layer. Any layers above or below it are ignored.
 3. 7. 1. Activate the Command
You can access this command from the image menubar through
Edit → Copy ,
or by using the keyboard shortcut
Ctrl + C .  3. 6. Cut 3. 8. Copy Visible
 Report an error in Bugzilla  3. 6. Cut 3. 6. Cut 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 6. Cut
The Cut command deletes the contents of the
image's selections, and saves them in a clipboard so that they can
later be pasted using the “ Paste ” , “ Paste
Into ” , or “ Paste As New ” commands. If there is no
selection , the entire current layer is cut. The areas whose contents
are cut are left transparent, if the layer has an alpha channel, or
filled with the layer's background color, otherwise.
Note
The Cut command only works on the current
active layer. Any layers above or below the active layer are ignored.
 3. 6. 1. Activate the Command
You can access this command from the image menubar through
Edit → Cut ,
or by using the keyboard shortcut
Ctrl + X .  3. 5. Undo History 3. 7. Copy
 Report an error in Bugzilla  3. 4. Fade 3. 4. Fade 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 4. Fade
This command is usually grayed out. It becomes active if you use the Fill
function or the Blend tool, or if you apply some filters.
It allows you to modify the paint mode and opacity of the
last drawable operation (Fill, Blend, Filter) by
creating a blend between the current state of the layer and the previous
state. It performs the following operations: copy the active drawable,
undo the last action, paste the copy as a new layer, set its
“ Opacity ” , and merge both new layer and previously active
drawable.
 3. 4. 1. Activate the command
You can get to this command from the image Menu bar through :
Edit → Fade...  3. 4. 2. Options
This command brings up a dialog window :
Figure 16.15. The “ Fade ” dialog Mode
This drop-down list allows you to choose a
Layer merge mode .
Opacity
This slider value is initially set to the opacity of the color
you used with the Fill or Blend tool, which corresponds to
the current state. Lowering the opacity to 0 changes the drawable
to its previous state. Intermediate values produce a mixture of
the two according to the mode you have chosen. The effect of
this setting is visible in real time in the image, but you have
to click on the Fade button to validate
it.
3.3. Redo 3.5. Undo History
 Report an error in Bugzilla  3. 15. Fill with BG Color 3. 15. Fill with BG Color 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 15. Fill with BG Color
The Fill with BG Color command fills the
active layer selection with the solid color shown in the Background
part of the Color Area of the Toolbox. (The color is also shown to the
left of the menu entry.) If some areas of the image are only partially
selected (for example, as a result of feathering the selection), they
are filled in proportion to how much they are selected.
Note
Please note that if the image has no selection, the whole active layer
is filled.
 3. 15. 1. Activate the Command
You can access this command from the image menubar through
Edit → Fill with BG Color ,
or by using the keyboard shortcut
Ctrl + . .
Note
You can also fill a selection by click-and-dragging from the
Toolbox background color.  3. 14. Fill with FG Color 3. 16. Fill with Pattern
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3. 14. Fill with FG Color 3. 14. Fill with FG Color 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 14. Fill with FG Color
The Fill with FG Color command fills the
image's selection with the solid color shown in the foreground part
of the Color Area of the Toolbox.
(The color is also shown to the left of the menu entry.) If
some areas of the image are only partially selected (for
example, as a result of feathering the selection), they are
filled in proportion to how much they are selected.
Note
Please note that if the image has no selection, the whole active layer
is filled.
 3. 14. 1. Activate the Command
You can access this command from the image menubar through
Edit → Fill with FG Color ,
or by using the keyboard shortcut
Ctrl + , .
Note
You can also fill a selection by click-and-dragging from the
Toolbox foreground color.  3. 13. Clear 3. 15. Fill with BG Color
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3. 16. Fill with Pattern 3.16. Fill with Pattern 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 16. Fill with Pattern The Fill with Pattern command fills the
image's selection with the pattern shown in the Brush/Pattern/Gradient
area of the Toolbox. (The pattern is also shown to the left of the
menu entry.) If some areas of the image are only partially selected
(for example, as a result of feathering the selection), they are filled
in proportion to how much they are selected.
You can select another pattern by using the
Pattern Dialog .
Note
Please note that if the image has no selection, the whole active layer
is filled.
 3. 16. 1. Activate the Command
You can access this command from the image menubar through
Edit → Fill with Pattern ,
or by using the keyboard shortcut
Ctrl + ; .  3. 15. Fill with BG Color 3. 17. Stroke Selection
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3. The “Edit” Menu 3. The “ Edit ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. The “ Edit ” Menu 3. 1. “ Edit ” Menu Entries Figure 16.14. Contents of the Edit Menu
In this section, you will find help for commands in the
Edit menu item.
Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
2.18. Quit 3.2. Undo
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3. 11. Paste as 3.11. Paste as 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 11. Paste as
This command pastes the clipboard contents. Of course, you must use
the “ Copy ” command before, so that you have something in the
clipboard. Else you will be prompted a warning:
or, if there is something you have forgotten, it will be pasted! There
is no way to empty the clipboard.
This command leads to the sub-menu:
Figure 16.16. The “ Paste as ” sub-menu
Section 3.11.1, “Paste as New Image” Section 3.11.2, “Paste as New Layer” Section 3.11.3, “Paste as New Brush” Section 3.11.4, “Paste as New Pattern”
3.11.1. Paste as New Image
The Paste As New Image command creates a new
image and pastes the image data from the Clipboard into it. If the data is
not rectangular or square in shape, any regions outside the selection are
left transparent ( an alpha channel is automatically created). Of course,
you have to copy your selection before you use this command , so that you
get an image with the same dimensions as the selection.
This command has the same action as the
File → Create → From Clipboard command.
 3. 11. 1. 1. Activate the Command
You can access this command from the image menubar through
Edit → Paste as → New Image .  3. 11. 2. Paste as New Layer
The Paste As New Layer command creates a new
layer in the active image and pastes the image data from the Clipboard
into it. If the data are not rectangular or square in shape, any regions
that do not extend to the edge of the canvas are left transparent ( an
Alpha channel is automatically created). Of course, you have to Copy your
selection before you use this command .
 3. 11.2. 1. Activate the Command
You can access this command from the image menubar through
Edit → Paste as → New Layer .  3. 11. 3. Paste as New Brush
This command opens a dialog window which lets you name the new brush.
The brush appears in the Brushes
dialog .
3.11.3.1. Options Figure 16.17. The “ New Brush ” dialog Brush name Brush name is the name as it will be in
the “ Brushes ” Dialog.
File name
The new brush is saved as File name (with
extension . gbr ) in your
personal brushes folder.
Spacing Spacing : When the brush draws a line, it
actually stamps the brush icon repeatedly. If brush stamps are
very close, you get the impression of a solid line .
 3. 11. 3. 2. Activate the Command
You can access this command from the image menubar through
Edit → Paste as → New Brush .  3. 11. 4. Paste as New Pattern
This command opens a dialog window which allows you to name your new
pattern. The pattern appears in the
Patterns dialog .
3. 11.4.1. Options Figure 16.18. The “ New Pattern ” dialog Pattern name Pattern name is the name as it will be in the
Pattern Dialog.
File name
The new pattern is saved as File name (with
extension . pat ) in your
personal patterns folder.
 3. 11. 4. 2. Activate the Command
You can access this command from the image menubar through
Edit → Paste as → New Pattern .  3. 10. Paste Into 3. 12. Buffer
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3. 10. Paste Into 3. 10. Paste Into 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 10. Paste Into
The Paste Into command acts in a similar way
to the Paste command. The primary difference
becomes apparent if there is a selection within the canvas. Unlike the
“ Paste ” command , which simply centers the pasted image
data over the selection and replaces the selection with its own,
“ Paste Into ” clips the pasted image data by the existing
selection. The new selection can be moved as usual, but it is always
clipped by the original selection area.
If no selection exists, the “ Paste Into ” command places
the data from the Clipboard into the center of the canvas, as the
“ Paste ” command does.
 3. 10. 1. Activate the Command
You can access this command from the image menubar through
Edit → Paste Into .  3. 9. Paste 3. 11. Paste as
 Report an error in Bugzilla  3. 9. Paste 3. 9. Paste 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 9. Paste
The Paste command puts whatever is in
the Clipboard from the last “ Copy ” or “ Cut ”
command into the current image. The pasted section becomes a
“ floating selection ” and is shown as a separate layer in the
Layers Dialog.
If there is an existing selection on the canvas, it is used to align
the pasted data. If there is already a selection, the data is pasted
using the selection as a center point. If you want the selection to be
used as a clipping region for the pasted data, you should use
the “ Paste Into ” command .
Note
You can have only one floating selection at any
one time. You cannot work on any other layer while there is a
floating selection ; you have to either anchor it or remove it.
 3. 9. 1. Activate the Command
You can access this command from the image menubar through
Edit → Paste .  or by using the keyboard shortcut
Ctrl + V .
3.8. Copy Visible 3.10. Paste Into
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3. 3. Redo 3.3. Redo 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 3. Redo
The Redo command reverses the effects of
the Undo command. Each
“ Undo ” action can be reversed by a single
“ Redo ” action. You can alternate “ Undo ” and
“ Redo ” as many times as you like. Note that you can
only “ Redo ” an operation if the last action you did was
an “ Undo ” . If you perform any operation on the image
after Undoing something, then the former Redo steps are lost, and
there is no way to recover them. See the
Undoing section for more
information.
To see the operations which you have done and undone, use the
Undo History dialog.
 3. 3. 1. Activating the Command
You can access this command from the image menubar through
Edit → Redo ,
by using the keyboard shortcut
Ctrl + Y ,
or by simply clicking on the status you want in the
Undo History dialog .  3. 2. Undo 3. 4. Fade
 Report an error in Bugzilla  3. 5. Undo History 3. 5. Undo History 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 5. Undo History
The Undo History command activates the
Undo History dialog , which
shows you thumbnails representing the operations you have done
so far on the current image. This overview makes it easier for
you to undo steps or to redo them.
Use the arrows for
Undo and
Redo , or simply click
on the thumbnail, to bring the image back to a previous state.
This is especially useful when you are working
on a difficult task, where you often need to undo several steps
at once. It is much easier to click on step 10 than to type
Ctrl + Z
ten times.
The “ Clear undo History ” command may be useful if you are
working on a complex image and you want to free some memory.
 3. 5. 1. Activating the Command
You can access this command from the image menubar through
Edit → Undo History .
There is no default keyboard shortcut.  3. 4. Fade 3. 6. Cut
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3. 2. Undo 3. 2. Undo 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Undo
If you have made drawing or editing changes to the image which you
don't want to keep, the Undo command allows you to
undo the last change and return the image to its previous state.
Almost anything you do to an image can be
undone in this way (with the exception of scripts, which deactivate
this function). Further Undo operations may be performed, depending
upon the number of Undo levels configured in the
Environment
page of the Preferences Dialog. See the section on
Undoing for more information about GIMP 's
very sophisticated “ Undo ” functions.
The operation that has been “ undone ” is not lost
immediately: you can get it back by using the
Redo command right away. But
if you perform another operation, the ability to “ Redo ” will
be irretrievably lost.
 3. 2. 1. Activate the Command
You can access this command from the image menubar through
Edit → Undo ,
by using the keyboard shortcut
Ctrl + Z ,
or by simply clicking on the status you want in the Undo
History dialog.  3. The “ Edit ” Menu 3. 3. Redo
 Report an error in Bugzilla  5. 4. Error Console 5. 4. Error Console 5. Misc. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 4. Error Console
The Error console offers more possibilities than
the single “ GIMP Message ” . This is a log of all errors
occurring while GIMP is running. You can save all this log or only a
selected part.
 5.4. 1. Activating the Dialog
The “ Error Console ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from an image menu:
Windows → Dockable Dialogs → Error Console ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Error Console . 
5. 4.2. The “ Error Console ” Dialog Figure 15.75. “ Error Console ” Dialog window Clear errors
This button lets you delete all errors in the log.
Warning
You can't “ undo ” this action.
Save all errors
This button lets you save
the whole log. You can also select a part of the log ( by
click-and-dragging the mouse pointer or by using the
Shift + Arrow
keys key combination) and save only this
selected part by pressing the Shift key .
A dialog window Save Error Log to File lets
you choose the name and the destination directory of this file:
Figure 15.76.
“ Save Error Log to file ” Dialog window
Tip
You will as well find these button actions in the dialog tab menu by
clicking on
,
or in the context menu you get by right-clicking on the dialog
window.
5.3. Device Status Dialog 5.5. Save File
 Report an error in Bugzilla  5. 6. Export File 5.6. Export File 5. Misc. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 6. Export File
With GIMP -2.8, the Save command saves images in XCF
format only. The Export command is now used to save images to various
file formats.
You can access to this command through
File → Export As... , or from the keyboard by using the shortcut
Ctrl + Shift + E .
Figure 15.78. Export Image Dialog 5.6.1. The Export Image Dialog
With this file browser, you can edit filename and extension directly in
name box (default is “ Untitled. png ” ) or by selecting a
file in name list. You must also fix the image destination in
Save in Folder . You can create a new folder if
necessary.
Select File Type.
If you develop this option, you can select an extension in the
drop-down list for your file:
File formats dialogs are described in
Section 1, “Files” .
5.6.2. Exporting
When file name and destination are set, click on
Export . This opens the export dialog for the
specified file format.
If you have loaded a non-XCF file, a new item appears in File menu,
allowing you to to export file in the same format, overwriting the
original file.
If you modify an image that you already have exported, the
Export command in File menu is changed, allowing you
to export file again in the same format.
5.5. Save File 5. 7. Sample Points Dialog  Report an error in Bugzilla  2. 17. Close all 2.17. Close all 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 17. Close all
This command closes all images you have opened .
 2. 17. 1. Activate the Command
You can access this command from the image menubar through
File → Close All ,
or by using the keyboard shortcut
Shift + Ctrl + W .  2. 16. Close 2. 18. Quit
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2. 16. Close 2. 16. Close 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 16. Close
The Close command closes the active image.It is
disabled if no image is open .
Closing an image is not undoable : once it is
closed, everything is gone, including the undo history. If the image
is not “ clean ” — that is, if you have changed it since the
last time you saved it — you are asked to confirm that you really want
to close it. Note that an image is marked as clean when it is saved to
a file, even if the file format chosen does not preserve all the
information in the image , so it is a good idea to think for a moment
about what you are doing before closing an image. If there is the
slightest possibility that you will regret it, save the file (automatically
in the XCF file format since GIMP -2.8).
 2. 16. 1. Activating the Command
You can access this command from the image menu through
File → Close ,
or by using the keyboard shortcut
Ctrl + W .
For most systems on which the GIMP runs,
you can also execute it by clicking on a
“ Close ” button somewhere on the image window titlebar.
The location and appearance of this button are determined by the
windowing system and the window manager. If no image is open ,
clicking on this button closes GIMP .  2. 15. Print 2. 17. Close all
 Report an error in Bugzilla  2. 14. Create Template 2. 14. Create Template 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 14. Create Template
The Create Template command creates a
template with the same dimensions and color space as the current
image. A dialog pops up, which asks you to
name the new template. Then the template is saved and becomes
available in the New Image
dialog. If you give a name that already exists,
GIMP generates a unique name
by appending a number to it. You can use the
Templates dialog
to modify or delete templates.
 2. 14. 1. Activating the Command
You can access this command from the image menu through
File → Create Template .
There is no default keyboard shortcut.  2. 13. Export As... 2. 15. Print
 Report an error in Bugzilla  2. 3. Create 2.3. Create 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 3. Create Figure 16.7. The “ Create ” submenu
This menu item replaces the “ Acquire ” menu which
existed in GIMP previous versions in the Toolbox
Menu and contains a lot of logos, buttons, patterns...
These commands vary somewhat, depending upon your system, since
the GIMP makes calls to system functions.
 2. 3.1. Activate the Submenu
You can access this submenu from the Image menu bar through
File → Create  2. 3.2. From Clipboard
When you copy a selection, it goes into the clipboard. Then you can
create a new image with it.
This command has the same action as the
Paste as new command.
The Print Screen keyboard key captures the screen and
puts it in the clipboard. This command has the same action as
“ taking a screenshot of the entire screen ” in the
Screenshot dialog window. The
Alt + Print Screen key combination grabs the active window in the screen
with its decorations and puts it in the clipboard.
2.3.3. From Web page
This command opens a dialog where you can enter the URL of a Web page and
get the image in GIMP.
The command defaults to gimp.org. Please have a try to it.
2.3.4. Screenshot Figure 16.8. The “ Screenshot ” window
The Screenshot command opens a
dialog with two parts:
Area Take a screenshot of a single window
The mouse pointer becomes a cross. Click in the image window
you want to capture. A new image is created . If the
Include window decoration option is
unchecked, the title bar and the blue frame around the image
will be removed.
Take a screenshot of the entire screen
This is useful if you want to capture a pop menu. A delay is
then necessary, so that you have time to pull the pop menu
down.
If the Include mouse pointer option is
checked, then the mouse pointer and its coming with icon are
also captured. The mouse pointer is captured in a separate
layer. So you can move it to another place in the image.
Select a region to grab
The mouse pointer becomes a cross. Click and drag to create
a rectangular selection in the image window. This selection
will be opened as a new image. Its size is adapted to the
selection size.
Delay
When taking a screenshot of the entire screen , the screen is
captured after this delay. In the other cases, the mouse pointer
turns to a cross after this delay.
2.3.5. Image capture devices
This item is present only if you have installed image capture
devices.
Figure 16.9. Scanner and Camera
The kinds of devices used to take pictures are too varied to be
described here. Fortunately, their use is fairly intuitive. In the
example shown, you can start a scanner or take an image with a
webcam.
2.3.6. Buttons, Logos, Patterns, Web Page Themes
An impressive list of script-fus. Have a look at it!
2.3.7. New brush from text...
TODO (this command fails on my system)
2.2. New 2.4. Open
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2. 12. Export 2. 12. Export 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 12. Export
This command is called “ Export ” for a native XCF file.
Then, it does the same thing as Export As .
At early GIMP 2.8 releases,
this menu label was “ Export to ” . Since the version 2.8.10,
“ Export to ” and “ Export ” have been renamed to
“ Export ” and “ Export As ” after the manner of
“ Save ” and “ Save As ” .
The name becomes “ Overwriting name.extension ” for an imported
image. So, you can export the imported image directly in its original
file format, without going through the export dialog.
2.11. Revert 2.13. Export As...
 Report an error in Bugzilla  2. 13. Export As... 2. 13. Export As... 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 13. Export As... Export As... allows you to save your image in a format
other than XCF .
Note
Please refer to Section 1, “Files” for information
about exporting in different file formats.
 2. 13. 1. Activating the Command
You can access this command from the image menubar through
File → Export As... ,
or by using the keyboard shortcut
Shift + Ctrl + E .  2. 12. Export 2. 14. Create Template
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2. The “File” Menu 2. The “ File ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. The “ File ” Menu 2. 1. Overview Figure 16.3. The File menu Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
Chapter 16. Menus 2.2. New
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2. 2. New 2.2. New 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. New
Using the New Image dialog, you can
create a new empty image and set its
properties. The image is shown in a new image window.
You may have more than one image on your screen at the same time.
 2. 2. 1. Activate the command
You can access the command in the Image menu through:
File → New ,
or by using the keyboard shortcut
Ctrl + N .  2. 2.2. Basic Options Figure 16.4. The “ New Image ” dialog Template Figure 16.5. The “ Template ” dialog
Rather than entering all the values by hand, you can select some
predefined values for your image from a menu of templates, which
represent image types that are somewhat commonly useful. The
templates set values for the size, resolution, comments, etc. If
there is a particular image shape that you use often and it
does not appear on the list, you can create a new template, using
the Templates dialog.
Image Size
Here you set the Width and
Height of the new image. The
default units are pixels, but you can choose a different
unit if you prefer, using the adjoining menu. If you do,
note that the resulting pixel size is determined by
the X and Y resolution (which you can change in the
Advanced Options ), and by setting
“ Dot for Dot ” in the
View menu .
If no image is open , the “ New ” image is opened in
the empty image window, with the default size you have determined.
If you open the “ New ” image when another is open (or
has been), then it is opened in another window, with the same
size as the first image.
Note
Keep in mind that every pixel of an image is stored
in memory. If you create large files with a high pixel
density, GIMP will need a lot
of time and memory for every function you apply to the
image.
Portrait/Landscape buttons
There are two buttons which toggle between Portrait and Landscape
mode. What they actually do is to exchange the values for Width
and Height. (If the Width and Height are the same, these buttons
are not activated.) If the X and Y resolutions are not the same
(which you can set in Advanced Options), then these values are
also exchanged. On the right of the dialog, image size, screen
resolution and color space are displayed.
2.2.3. Advanced Options Figure 16.6. New Image dialog (Advanced Options)
The Advanced Options
are mostly of interest to more advanced GIMP
users. You can display these options by clicking on the small triangle
on the lower edge of the dialog window.
X and Y resolution
The values in the X resolution and
Y resolution
fields relate mainly to printing: they do not affect the size of
the image in pixels, but they may determine its physical size when
it is printed. The X and Y resolution values can determine how
pixels are translated into other measurement units, such as
millimeters or inches.
Tip
If you want to display the image on the screen at the
correct dimensions, select
View → Dot for Dot
Set the zoom factor to 100% to see the image at its true
screen size. The calibration of the screen size is normally
done when GIMP is installed,
but if the image does not display at the correct size,
you may have to adjust the screen parameters in the
GIMP . You can do this in the Preferences
dialog.
Colorspace
You can create the new image in different
color modes , as either an
RGB image or a grayscale image.
RGB color
The image is created in the Red, Green, Blue color system,
which is the one used by your monitor or your television
screen.
Grayscale
The image is created in black and white, with various shades
of gray. Aside from your artistic interests, this type of
image may be necessary for some plug-ins. Nevertheless, the
GIMP allows you to
change an RGB
image into grayscale , if you would like.
You cannot create an indexed image directly with this menu, but of
course you can always convert the image to indexed mode after it
has been created. To do that, use the Image → Mode → Indexed command.
Fill
Here, you specify the background color that is used for your new
image. It is certainly possible to change the background of an
image later, too. You can find more information about doing that
in the Layer dialog .
There are several choices:
Fill the image with the current Foreground
color , shown in the Toolbox.
Note that you can change the foreground color while the
“ New Image ” dialog window is open.
Fill the image with the current Background
color , shown in the Toolbox. (You can change the
background color too, while the dialog window is open.)
Fill the image with White .
Fill the image with Transparency . If you
choose this option, the image is created with an alpha channel and
the background is transparent. The transparent parts of the
image are then displayed with a checkered pattern, to indicate
the transparency.
Comment
You can write a descriptive comment here. The text is
attached to the image as a
parasite , and is saved
with the image by some file formats ( PNG, JPEG, GIF).
Note
You can view and edit this comment in the
Image Properties dialog.
2. The “ File ” Menu 2. 3. Create
 Report an error in Bugzilla  2.5. Open as Layers 2. 5. Open as Layers 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 5. Open as Layers
The Open Image as layers dialog is identical to the
Open Image dialog. The layers of the
selected file are added to the current image as the top layers in the
stack.
 2.5. 1. Activate Command
You can access this command from the image menubar through
File → Open as layers ,
or by using the keyboard shortcut
Ctrl + Alt + O .  2.4. Open 2. 6. Open Location
 Report an error in Bugzilla  2. 6. Open Location 2. 6. Open Location 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 6. Open Location
The Open Location dialog lets you load an
image from a network location, specified by a URI, in any of the formats
that GIMP supports.
 2. 6. 1. Activate Command
You can access this command from the Toolbox menubar or the
image menubar through
File → Open Location… .  2. 6. 2. Description of the dialog window Figure 16. 11. The “ Open Location ” dialog window The most typical schemes to open images with are: file: // to open an image from a local drive
You can omit the “ file:// ” prefix and open images
simply by putting an absolute or relative path and filename in
here.
The default base directory for relative paths depends on your
operating system. It is typically
/home/ & lt;username & gt;/ on Linux,
C:\Documents and
Settings\ & lt;username & gt;\My Documents\My Images\
on Windows and
/Users/ & lt;username & gt;/ on Mac OS X.
ftp: // to open an image from a ftp server http:// to load an image from a website Tip
When you are visiting an Internet site, you can right-click on
an image and choose “ Copy link address ”
in the drop-down menu. Then paste it in the
“ Open Location ” dialog to open it in GIMP .
Even if this command makes it very easy to grab images from
web sites:
Please respect the copyright! Images, even if published on the
Internet are not always free to be used for you.
2.5. Open as Layers 2. 7. Open Recent
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2. 7. Open Recent 2. 7. Open Recent 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 7. Open Recent
Selecting Open Recent displays a submenu with
the names of the files that you have opened recently in
GIMP . Simply click on a name to reopen it. See the
Document History dialog at the
bottom of the Open Recent submenu, if you cannot find your image.
 2. 7. 1. Activate Command
You can access this command from the
image menubar through
File → Open Recent ,  2. 6. Open Location 2. 8. Save
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2. 4. Open 2. 4. Open 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 4. Open
The Open command activates a dialog that lets
you load an existing image from your hard-drive or an external medium.
For alternative, and sometimes more convenient, ways of opening files, see
the following commands ( Section 2.5, “Open as Layers” etc.).
 2.4.1. Activate Dialog
You can access the Open dialog
from an image window through:
File → Open .
You can also open the Dialog by using the keyboard shortcut
Ctrl + O .  2.4. 2. File browsing Figure 16.10. Open Dialog
This browser looks like other browsers and it is mostly
self-explanatory. It has some particuliar features nevertheless.
The button Type a file name toggles between
add and remove the Location text box.
The Ctrl + L
key combination has the same action as this button.
In the Location text box you can type a path to
an image file. If you don't type any path, the name of the selected
file will be displayed. You can also type the first letters of the
name: it will be auto-completed and a list of file names beginning
with these letters will be displayed.
When you search for a file or directory using the
Search feature (see below, item 4), the label
changes to Search and you can enter the name in
this text box .
The path to the current folder is displayed. You can navigate along
this path by clicking on an element .
With Search you can look for a file (or
directory ), even if you don't know the exact name of that file.
Click on Search , type a file name or just a
part of a file name in the text box above, and press
Enter . Then the central frame (7) will list all
files and directories of your home directory with names containing
the text you typed in. Unfortunately you can't restrict the results
to files of a specified type (10).
Recently used is self-explanatory.
Here, you can access to your main folders and to your store devices.
Here, you can add bookmarks to folders, by using the
Add or the Add to
Bookmarks option you get by right-clicking a folder in
the central panel, and also remove them.
The contents of the selected folder is displayed here. Change your
current folder by double left clicking on a folder in this
panel. Select a file with a single left click. You can then open
the file you have selected by clicking on the
Open button.
A double left click opens the file directly. Please note that you
can open image files only.
Right-clicking a folder name opens a context menu:
The folder context menu
The selected image is displayed in the Preview
window. If it is an image created by GIMP , file
size, resolution and image composition are displayed below the
preview window.
Tip
If your image has been modified by another program, click on the
Preview window to update it.
By clicking the Add button, you add the
selected folder to bookmarks.
By clicking the Remove , you remove the
selected bookmark from the list.
You will generally prefer to display the names of
All images . You can also select
All files . You can also limit yourself to
a particular type of image (GIF, JPG, PNG ...).
Select File Type : In most cases you
don't need to pay any attention to this, because
GIMP can determine the file type
automatically. In a few rare situations, neither the file
extension nor internal information in the file are enough to tell
GIMP the file type. If this happens,
you can set it by selecting it from the list.
2.3. Create 2.5. Open as Layers  Report an error in Bugzilla  3. 19. The “Preferences” Command 3.19. The “ Preferences ” Command 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 19. The “ Preferences ” Command
This command displays the
Preferences dialog ,
which lets you alter a variety of settings that affect the look, feel,
and performance of the GIMP .
 3. 19. 1. Activate Command
You can access this command in the image menu bar through
Edit → Preferences  3. 18. Stroke Path 3. 20. Keyboard Shortcuts
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2. 18. Quit 2.18. Quit 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 18. Quit
The Quit command causes
GIMP to close all images and exit. If there
are any open images which contain unsaved changes (that is, they are
not marked as “ clean ” ),
GIMP notifies you and displays a list of
the unsaved images. You can then choose which images you would
like to save , or you can cancel the command. Note
that if you have a large number of images open, or are using a
large part of the RAM on your system, it may take a little
while for everything to shut down.
 2. 18. 1. Activate Command
You can access this command from the image menubar through
File → Quit ,
or by using the keyboard shortcut
Ctrl + Q .
For most systems on which the GIMP runs,
you can also execute it by clicking on a
“ Close ” button somewhere on the main image window's
titlebar. The location and appearance of this button are
determined by the windowing system and the window manager. Clicking on this button closes GIMP when no image is open.  2. 17. Close all 3. The “ Edit ” Menu
 Report an error in Bugzilla  2. 11. Revert 2.11. Revert 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 11. Revert
The Revert command reloads the image from
disk, so that it looks just like it did the last time it was saved
— unless, that is, you or some application other than
GIMP have modified the image file, in
which case, the new contents are loaded.
Warning
When GIMP reverts a
file, it actually closes the existing image and creates a new
image. Because of this, reverting an image is not undoable, and
causes the undo history of the image to be lost.
GIMP tries to protect you from losing your
work in this way by asking you to confirm that you really want to
revert the image.
 2. 11. 1. Activate Command
You can access this command from the image menubar through
File → Revert .
There is no default keyboard shortcut.  2. 10. Save a Copy 2. 12. Export
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2. 10. Save a Copy 2. 10. Save a Copy 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 10. Save a Copy
The Save a Copy command does the same thing
as the Save command, but with one important
difference. It always asks for a file name and saves the image into the
XCF file format, but it does not change the name of the active image
or mark it as “ clean ” . As a result, if you try to delete
the image, or exit from GIMP , you are
informed that the image is “ dirty ” and given an opportunity
to save it.
This command is useful when you want to save a copy of your image in
its current state, but continue to work with the original file without
interruption.
 2. 10. 1. Activate Command
You can access this command from the image menubar through
File → Save a Copy .
There is no default keyboard shortcut.  2. 9. Save as 2. 11. Revert
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2. 9. Save as 2. 9. Save as 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 9. Save as
The Save as command displays the “ Save
Image ” dialog . Since GIMP -2.8, the
file is automatically saved in the XCF format and you can't
save in another file format (for this, you have to
export the file). The Save as dialog allows you to
save with another name and/or to another folder.
 2. 9. 1. Activating the Command
You can access this command from the image menubar through
File → Save as ,
or by using the keyboard shortcut
Shift + Ctrl + S .  2. 9. 2. The “ Save Image ” dialog Figure 16. 12. The “ Save Image ” dialog
The left panel is divided into two parts . The upper part lists
your main directories and your storage devices; you cannot modify
this list. The lower part lists your bookmarks; you can add or
remove bookmarks . To add a bookmark, select a
directory or a file in the middle panel and click on the
Add button at the bottom of the left
panel. You can also use the Add to bookmarks
command in the context menu , which you get by clicking the
right mouse button. You can delete a bookmark by selecting
it and clicking on the Remove button.
The middle panel displays a list of the files in the current
directory. Change your current directory by double left-clicking on
a directory in this panel. Select a file with a single left click.
You can then save to the file you have selected by clicking on the
Save button. Note that a double left click
saves the file directly.
You can right click on the middle panel to access the
Show Hidden Files command.
The selected image is displayed in the Preview
window. File size, resolution and image
composition are displayed below the preview window.
If your image has been modified by another program,
click on the preview to update it.
Enter the filename of the new image file here. Note
If the image has already been saved,
GIMP suggests the same filename to
you. If you click on Save , the file
is overwritten.
Above the middle panel, the path of the current directory is
displayed. You can navigate along this path by clicking on one of
the buttons.
If you want to save the image into a folder that doesn't yet
exist, you can create it by clicking on
Create Folder and following the instructions.
This button shows All Images by default. This
means that all images will be displayed in the middle panel,
whatever their file type. By developing this list, you can choose
to show only one type of file.
At Select File Type , you can select a compressed
format for your XCF file .
2.8. Save 2.10. Save a Copy
 Report an error in Bugzilla  2.8. Save 2.8. Save 2. The “ File ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 8. Save
This command opens Section 5.5, “Save File” .
2.7. Open Recent 2. 9. Save as
 Report an error in Bugzilla 
10. 2. Repeat Last 10. 2. Repeat Last 10. The “ Filters ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 2. Repeat Last
The Repeat Last command performs the action
of the most recently executed plug-in again, using the same settings as
the last time it was run. It does not show a dialog or request
confirmation.
Note
Please note that this command repeats the most recently executed
plug-in , regardless of whether it is in the
Filters menu or not.
 10. 2. 1. Activating the Command
You can access this command from the image menubar through
Filters → Repeat
filter ,
or by using the keyboard shortcut
Ctrl + F .  10. The “ Filters ” Menu 10. 3. Re-show Last
 Report an error in Bugzilla  10. 4. Reset All Filters 10. 4. Reset All Filters 10. The “ Filters ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 4. Reset All Filters
Normally, each time you run an interactive plug-in, its dialog is
displayed with all of the settings initialized to the ones you used
the last time you ran it. This may be a problem if you made a mistake
setting the values and you can't remember what they were originally.
One way to recover is to exit GIMP and
start again, but the Reset all Filters
command is a slightly less drastic solution: it resets the values for
all plug-ins to their defaults. Because it is a
dramatic step, it asks you to confirm that you really want to do it .
Be careful: you cannot undo this command.
 10.4. 1. Activating the Command
You can access this command from the image menubar through
Filters → Reset all Filters .  10. 3. Re-show Last 10. 5. The “ Python- Fu ” Submenu  Report an error in Bugzilla 
10. 3. Re-show Last 10. 3. Re-show Last 10. The “ Filters ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 3. Re-show Last
The Re-show Last command shows the dialog of
the most recently executed plug-in . Unlike the
“ Repeat Last ” command, which does not display a dialog,
the “ Re-show Last ” command displays a dialog window , if the
plug-in has one. It is displayed with the settings you used the
last time you ran the plug-in (assuming that the plug-in follows
the GIMP programming conventions).
Note
Please note that this command repeats the most recently
executed plug-in ,
regardless of whether it is in the Filters
menu or not.
Tip
When you are using a plug-in, especially one that does not have
a preview window, you may very well have to adjust the parameters
several times before you are satisfied with the results. To do this
most efficiently, you should memorize the shortcuts for
Undo and
Re-show Last :
Ctrl + Z
followed by
Ctrl + Shift + F .
 10. 3. 1. Activating the Command
You can access this command from the image menubar through
Filters →
Re-show filter
,
or by using the keyboard shortcut
Ctrl + Shift + F .  10. 2. Repeat Last 10. 4. Reset All Filters  Report an error in Bugzilla  10. The “Filters” Menu 10. The “ Filters ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. The “ Filters ” Menu 10. 1. Introduction to the “ Filters ” Menu Figure 16.201. The “ Filters ” menu
In GIMP
terminology, a filter
is a plug-in that modifies the appearance of an image, in most cases just
the active layer of the image . Not all of the entries in this menu meet
that definition, however; the word “ filter ” is often
mis-used to mean any plug-in, regardless of what it does. Indeed, some
of the entries in this menu do not modify images at all.
With the exception of the top three items of the
Filters menu, all of the entries
are provided by plug-ins. Each plug-in decides for itself where it would
like its menu entry to be placed. Therefore, the appearance of this menu
can be completely different for each user. In practice, though, the
appearance does not vary very much, because most plug-ins come with
GIMP when it is installed , and of course
they are always in the same places in the menu.
Plug-ins are not restricted to just the Filters
menu: a plug-in can place entries in any menu. Indeed, a number of
GIMP 's basic
functions (for example, Semi-flatten
in the Layer menu) are implemented
by plug-ins . But the Filters menu is the default
place for a plug-in to place its menu entries.
For general information on plug-ins and how to use them , see the section
on Plug-ins . You can find
information on the filters that are provided with
GIMP in the
Filters chapter. For filters you install
yourself, please refer to the information which came with them.
9. The “ Tools ” Menu 10.2. Repeat Last
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10. 5. The “Python-Fu” Submenu 10.5. The “ Python- Fu ” Submenu 10. The “ Filters ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 5. The “ Python- Fu ” Submenu Figure 16. 202. The “ Python-Fu ” submenu
By default this submenu just contains the Python-Fu console.
Python-Fu
is a set of Python
modules that act as a wrapper to libgimp allowing
the writing of plug-ins for GIMP .
 10.5. 1. Activating the submenu
You can access this command from the image menu through
Filters → Python-Fu 
10.5.2. The Python-Fu Console
The Python- Fu console is a dialog window running a “ Python
shell ” (a Python interpreter in interactive mode). This console
is set up to make use of the internal GIMP library
routines of libgimp .
You can use the Python-Fu console to interactively test Python commands.
The console consists of a large scrollable main window for input and
output, where you can type Python commands. When you type in a Python
command and then press the Enter key, the command is
executed by the Python interpreter. The command's output as well as its
return value (and its error message, if any) will be displayed in the
main window.
Figure 16. 203. The Python-Fu Console The Python-Fu Console Buttons Save
This command lets you save the content of the main window, that is
the Python-Fu console input and output (including the
“ & gt; & gt; & gt; ” prompt).
Clear
Wenn you click on this button, the content of the main window will
be removed. Note that you can't get back the removed content using
the Save command.
Browse
When clicked, the
procedure browser pops
up, with an additional button Apply at the
bottom of the window .
When you press this Apply button in the
procedure browser, a call to the selected procedure will be pasted
into the console window as a Python command:
Applied PDB procedure
Now you just have to replace the parameter names (here:
“ width ” , “ height ” , and
“ type ” ) with actual values, e.g.
image = pdb.gimp_image_new(400, 300, RGB)
Then press Enter to execute the command.
You can (and should!) use the constants you find in the decription
of the procedure's parameters, for example
“ RGB-IMAGE ” or “ OVERLAY-MODE ” . But note
that you have to replace hyphens ( “ - ” ) with
underscores ( “ _ ” ): RGB_IMAGE ,
OVERLAY_MODE .
Tip
Python-Fu is not limited to just calling procedures from the
PDB
( GIMP procedural database). To create a new
image object like in the example above, you can also type
image = gimp.Image(width, height, type)
(with actual values for “ width ” ,
“ height ” , and “ type ” ) .
Close
Pressing this button closes the console.
10.4. Reset All Filters 10. 6. The “ Script- Fu ” Submenu  Report an error in Bugzilla 
10. 6. The “Script-Fu” Submenu 10.6. The “ Script- Fu ” Submenu 10. The “ Filters ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 6. The “ Script- Fu ” Submenu Figure 16. 204. The “ Script-Fu ” submenu
This submenu contains some Script-Fu commands, especially the Script-Fu
console. Script-Fu is a
language for writing scripts, which allow you to run a series of
GIMP commands automatically.
 10. 6. 1. Activating the submenu
You can access this command from the image menu through
Filters → Script-Fu  10. 6.2. Refresh Scripts
You will need this command every time you add, remove, or change a
Script-Fu script. The command causes the Script-Fus to be reloaded and
the menus containing Script-Fus to be rebuilt from scratch. If you
don't use this command, GIMP won't notice your
changes until you start it again.
Note that you won't get any feedback, unless saving, if one of your
scripts fails.
10.6.3. Script-Fu Console
The Script- Fu console is a dialog window where you can interactively
test Scheme commands.
The console consists of a large scrollable main window for output and a
textbox used to type Scheme commands. When you type a Scheme statement
and then press the Enter key, the command and its
return value will be displayed in the main window.
Figure 16. 205. The Script-Fu Console
You will find more information about
Scheme and
examples how to use the
Script-Fu
console in Section 3, “A Script-Fu Tutorial” .
The Script-Fu Console Buttons Browse
This button is next to the Scheme commands textbox. When
clicked, the
procedure browser pops
up, with an additional button at the bottom of the window :
The additional button of the Procedure Browser
When you press this Apply button in the
procedure browser, the selected procedure will be pasted into the
text box:
Applied
PDB
procedure
Now you just have to replace the parameter names (here:
“ layer ” and “ mode ” ) with actual values,
and then you can call the procedure by pressing
Enter .
Close
Pressing this button closes the Script-Fu console.
Clear
Wenn you click on this button, the content of the main window will
be removed. Note that you can't get back the removed content using
the Save command.
Save
This command lets you save the content of the main window, that is
the Script-Fu console output (including the
“ & gt; ” -characters).
10.6.4. Start Server
This command will start a server, which reads and executes Script-Fu
(Scheme) statements you send him via a specified port.
Figure 16.206. The Script-Fu Server Options Server Port
The port number where the Script-Fu server will listen. It is
possible to start more than one server, specifying different port
numbers, of course.
Server Logfile
Optionally you can specify the name of a file the server will use
to log informal and error messages. If no file is specified,
messages will be written to stdout.
The Script-Fu Server Protocol
The protocol used to communicate with the Script-Fu server is very
simple:
Every message (Script-Fu statement) of length L sent to
the server has to be preceded with the following 3 bytes:
Table 16.1. Header format for commands Byte # Content Description 0 0x47 Magic byte ('G') 1 L div 256 High byte of L 2 L mod 256 Low byte of L
Every response from the server (return value or error message) of
length L will be preceded with the following 4 bytes:
Table 16.2. Header format for responses Byte # Content Description 0 0x47 Magic byte ('G') 1 error code 0 on success, 1 on error 2 L div 256 High byte of L 3 L mod 256 Low byte of L Tip
If you don't want to get your hands dirty: there is a Python script
named servertest.py shipped with the
GIMP source code , which you can use as a simple
command line shell for the Script-Fu server.
10.5. The “ Python-Fu ” Submenu 11. “ Windows ” Menu  Report an error in Bugzilla  Chapter 2. Fire up the GIMP Chapter 2. Fire up the GIMP Part I. Getting Started  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 2. Fire up the GIMP Table of Contents 1. Running GIMP 1.1. Known Platforms 1.2. Language 1.3. Command Line Arguments 2. Starting GIMP the first time 2.1. Finally . . . 1. Running GIMP
Most often, you start GIMP either by clicking on an
icon (if your system
is set up to provide you with one), or by typing gimp
on a command line. If you have multiple versions of
GIMP installed,
you may need to type gimp-2.8
to get the latest version. You can, if you want, give a list of image
files on the command line after the program name, and they will
automatically be opened by GIMP as it starts. It is
also possible, though, to open files from within
GIMP once it is running.
Most operating systems support file associations, which associates a
class of files (as determined by their filename extension, such as .jpg)
with a corresponding application (such as GIMP ).
When image files are properly “ associated ” to
GIMP , you can double click on an image to open it
in GIMP .
1.1. Known Platforms
The GIMP is the most widely supported image
manipulation available today. The platforms on which
GIMP is known to work include:
GNU /Linux ™,
Apple Mac OS X ™,
Microsoft Windows ™,
OpenBSD ™, NetBSD ™,
FreeBSD ™, Solaris ™,
SunOS ™, AIX ™,
HP-UX ™, Tru64 ™,
Digital UNIX ™,
OSF/1 ™, IRIX ™,
OS/2 ™, and
BeOS ™.
The GIMP is easily ported to other
operating systems because of its source code availability. For further
information visit the GIMP developers homepage.
[ GIMP-DEV ] .
1.2. Language GIMP automatically detects and uses the system
language. In the unlikely event that language detection fails, or if
you just want to use a different language, since
GIMP -2.8, you can do so through:
Edit → Preferences → Interface .
You can also use:
Under Linux In LINUX : in console mode,
type LANGUAGE=en gimp or
LANG=en gimp
replacing en by fr, de, ... according to the language you
want. Background: Using LANGUAGE=en
sets an environment variable for the executed
program gimp .
Under Windows XP Control Panel → System → Advanced → Environment
button in “ System Variables ” area:
Add button: Enter LANG for Name and fr or
de... for Value. Watch out! You have to click on three successive
OK to validate your choice.
If you change languages often, you can create a batch file to
change the language. Open NotePad. Type the following
commands (for french for instance):
set lang=fr
start gimp-2.8.exe
Save this file as GIMP-FR.BAT (or another
name, but always with a
.BAT extension). Create
a shortcut and drag it to your desktop.
Another possibility:
Start → Programs → GTK Runtime Environment
Then Select language and select the
language you want in the drop-down list .
Under Apple Mac OS X
From System Preferences, click on the International icon. In
the Language tab, the desired language should be the first in the
list.
Another GIMP instance
Use -n to run multiple instances of GIMP.
For example, use gimp-2.8 to start GIMP
in the default system language, and
LANGUAGE=en gimp-2.8 -n to start another
instance of GIMP in English; this is very
useful for translators.
1.3. Command Line Arguments
Although arguments are not required when starting
GIMP , the most
common arguments are shown below. On a Unix system, you can use
man gimp for a complete list.
Command line arguments must be in the command line that you use
to start GIMP as
gimp-2.8 [OPTION...] [FILE|URI...] .
-?, --help Display a list of all commandline options. --help-all Show all help options. --help-gtk Show GTK+ Options. -v, --version
Print the GIMP version and exit.
--license Show license information and exit. --verbose Show detailed start-up messages. -n, --new-instance Start a new GIMP instance. -a, --as-new Open images as new. -i, --no-interface Run without a user interface. -d, --no-data
Do not load patterns, gradients, palettes, or brushes. Often
useful in non-interactive situations where start-up time is to be
minimized.
-f, --no-fonts Do not load any fonts. This is useful to load
GIMP
faster for scripts that do not use fonts, or to find problems
related to malformed fonts that hang GIMP .
-s, --no-splash Do not show the splash screen while starting. --no-shm Do not use shared memory between GIMP and
plugins. --no-cpu-accel Do not use special CPU acceleration
functions. Useful for finding or disabling buggy accelerated
hardware or functions. --session= name
Use a different sessionrc for this
GIMP
session. The given session name is appended to the default
sessionrc filename.
--gimprc= filename
Use an alternative gimprc instead of the
default one. The gimprc file contains a
record of your preferences. Useful in cases where plugins paths
or machine specs may be different.
--system-gimprc= filename Use an alternate system gimprc file.
-b, --batch= commands
Execute the set of commands non-interactively. The set of commands
is typically in the form of a script that can be executed by one
of the GIMP scripting extensions.
When the command is - , commands
are read from standard input.
--batch-interpreter= proc Specify the procedure to use to process batch commands.
The default procedure is Script-Fu. --console-messages
Do not popup dialog boxes on errors or warnings. Print the
messages on the console instead.
--pdb-compat-mode= mode PDB compatibility mode (off|on|warn). --stack-trace-mode= mode Debug in case of a crash (never|query|always). --debug-handlers Enable non-fatal debugging signal
handlers. Useful for GIMP debugging. --g-fatal-warnings Make all warnings fatal. Useful for debug. --dump-gimprc Output a gimprc file with default
settings. Useful if you messed up the gimprc file. --display= display
Use the designated X display (does not apply to all platforms).
2. What's New in GIMP 2.8? 2. Starting GIMP the first time  Report an error in Bugzilla  Chapter 3. First Steps with Wilber Chapter 3. First Steps with Wilber Part I. Getting Started  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 3. First Steps with Wilber Table of Contents 1. Basic Concepts 2. Main Windows 2.1. The Toolbox 2.2. Image Window 2.3. Dialogs and Docking 3. Undoing 3.1. Things That Cannot be Undone 4. Common Tasks 4.1. Intention 4.2. Change the Size of an Image for the screen 4. 3. Change the Size of an Image for print 4.4. Compressing Images 4. 5. Crop An Image 4. 6. Find Info About Your Image 4.7. Change the Mode 4.8. Flip An Image 4. 9. Rotate An Image 4.10. Separating an Object From Its Background 5. How to Draw Straight Lines 5.1. Intention 5.2. Examples 1. Basic Concepts Figure 3.1. Wilber, the GIMP mascot
The Wilber_Construction_Kit (in src/images/) allows you to give the
mascot a different appearance. It is the work of Tuomas Kuosmanen
(tigertATgimp.org).
This section provides a brief introduction to the basic concepts and
terminology used in GIMP . The concepts presented here
are explained in
much greater depth elsewhere. With a few exceptions, we have avoided
cluttering this section with a lot of links and cross-references:
everything mentioned here is so high-level that you can easily
locate it in the index.
Images
Images are the basic entities used by GIMP .
Roughly speaking, an “ image ” corresponds to a single
file, such as a TIFF or JPEG file. You can also think of an image
as corresponding to a single display window (although in truth it
is possible to have multiple windows all displaying the same image).
It is not possible to have a single window display more than one
image, though, or for an image to have no window displaying it.
A GIMP image may be quite a complicated thing.
Instead of thinking of it as a sheet of paper with a
picture on it, think of it as more like a stack of sheets, called
“ layers ” . In addition to a stack of layers, a
GIMP image may contain a selection mask, a set of
channels, and a set of paths. In fact, GIMP
provides a mechanism for attaching arbitrary pieces of data, called
“ parasites ” , to an image.
In GIMP , it is possible to have many images open
at the same time . Although large images may use many megabytes of
memory, GIMP uses a sophisticated
tile-based memory management system that allows
GIMP to handle very large images gracefully.
There are limits, however, and having more memory available
may improve system performance.
Layers
If a simple image can be compared to a single sheet of paper, an
image with layers is likened to a sheaf of transparent papers
stacked one on top of the other. You can draw on each paper, but
still see the content of the other sheets through the transparent
areas. You can also move one sheet in relation to the others.
Sophisticated GIMP users often deal with images
containing many layers, even dozens of them. Layers need not be
opaque, and they need not cover the entire extent of an image, so
when you look at an image's display, you may see more than just the
top layer: you may see elements of many layers.
Resolution
Digital images comprise of a grid of square elements of varying
colors, called pixels. Each image has a pixel size, such as 900
pixels wide by 600 pixels high. But pixels don't have a set size in
physical space. To set up an image for printing, we use a value
called resolution, defined as the ratio between an image's size in
pixels and its physical size (usually in inches) when it is printed
on paper. Most file formats (but not all ) can save this value, which
is expressed as ppi — pixels per inch. When printing a file,
the resolution value determines the size the image will have on
paper, and as a result, the physical size of the pixels. The same
900x600 pixel image may be printed as a small 3x2" card with barely
noticeable pixels — or as a large poster with large, chunky
pixels. Images imported from cameras and mobile devices tend to
have a resolution value attached to the file. The value is usually
72 or 96ppi. It is important to realize that this value is arbitrary
and was chosen for historic reasons. You can always change the
resolution value inside GIMP — this has no
effect on the actual image pixels. Furthermore, for uses such as
displaying images on line, on mobile devices, television or video
games — in short, any use that is not print — the
resolution value is meaningless and is ignored, and instead the
image is usually displayed so that each image pixel conforms to one
screen pixel.
Channels
A Channel is a single component of a pixel's color. For a colored
pixel in GIMP , these components are usually Red,
Green, Blue and sometimes transparency ( Alpha). For a
Grayscale image, they are
Gray and Alpha and for an
Indexed color image,
they are Indexed and Alpha.
The entire rectangular array of any one of the color components for
all of the pixels in an image is also referred to as a Channel. You
can see these color channels with the
Channels dialog .
When the image is displayed , GIMP puts these
components together to form the pixel colors for the screen,
printer, or other output device. Some output devices may use
different channels from Red, Green and Blue. If they do,
GIMP 's channels are converted into the
appropriate ones for the device when the image is displayed .
Channels can be useful when you are working on an image which needs
adjustment in one particular color. For example, if you want to
remove “ red eye ” from a photograph, you might work on
the Red channel.
You can look at channels as masks which allow or restrict the output
of the color that the channel represents. By using Filters on the
channel information, you can create many varied and subtle effects
on an image. A simple example of using a Filter on the color
channels is the
Channel Mixer
filter.
In addition to these channels, GIMP also allows
you to create other channels (or more correctly, Channel Masks),
which are displayed in the lower part of the Channels dialog. You
can create a New Channel or
save a selection to a
channel (mask) .
See the glossary entry on
Masks for more information
about Channel Masks.
Selections
Often when modify an image, you only want a part of the image
to be affected. The “ selection ”
mechanism makes this possible. Each image has its own selection,
which you normally see as a moving dashed line separating the
selected parts from the unselected parts (the so- called
“ marching ants ” ). Actually this is a bit misleading:
selection in GIMP
is graded, not all-or-nothing, and really the selection is
represented by a full-fledged grayscale channel . The dashed line
that you normally see is simply a contour line at the 50%-selected
level. At any time, though, you can visualize the selection channel
in all its glorious detail by toggling the
QuickMask
button.
A large component of learning how to use GIMP
effectively is acquiring the art of making good
selections—selections that contain exactly what you need and nothing
more. Because selection-handling is so centrally important,
GIMP provides many tools for doing
it: an assortment of selection-making tools, a menu of selection
operations, and the ability to switch to Quick Mask mode, in which
you can treat the selection channel as though it were a color
channel, thereby “ painting the selection ” .
Undoing
When you make mistakes, you can undo them. Nearly everything you can
do to an image is undoable. In fact, you can usually undo a
substantial number of the most recent things you did, if you decide
that they were misguided. GIMP makes this
possible by keeping a history of your actions. This history consumes
memory, though, so undoability is not infinite. Some actions use
very little undo memory, so that you can do dozens of them before
the earliest ones are deleted from this history; other types of
actions require massive amounts of undo memory. You can configure
the amount of memory GIMP allows for the undo
history of each image, but in any situation, you should always be
able to undo at least your 2-3 most recent actions. (The most
important action that is not undoable is closing an image. For this
reason, GIMP asks you to confirm that you really
want to close the image if you have made any changes to it.)
Plug-ins
Many, probably most, of the things that you do to an image in
GIMP are done by the GIMP
application itself. However, GIMP also makes
extensive use of “ plug-ins ” , which are external programs
that interact very closely with GIMP , and are
capable of manipulating images and other GIMP
objects in very sophisticated ways. Many important plug-ins are
bundled with GIMP , but there are also
many available by other means. In fact, writing
plug-ins (and scripts) is the easiest way for people not on the
GIMP development team to add new capabilities to
GIMP .
All of the commands in the Filters menu, and a substantial number of
commands in other menus, are actually implemented as plug-ins.
Scripts
In addition to plug-ins, which are programs written in the C
language, GIMP can also make use of scripts. The
largest number of
existing scripts are written in a language called Script-Fu, which
is unique to GIMP (for those who care, it is a
dialect of the
Lisp-like language called Scheme). It is also possible to write
GIMP
scripts in Python or Perl. These languages are more flexible and
powerful than Script-Fu; their disadvantage is that they depend on
software that does not automatically come packaged with
GIMP , so
they are not guaranteed to work correctly in every
GIMP
installation.
2. Starting GIMP the first time 2. Main Windows
 Report an error in Bugzilla 
3. 7. Fonts Dialog 3.7. Fonts Dialog 3. Image-content Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 7. Fonts Dialog Figure 15.61. The Fonts dialog
The “ Fonts ” dialog is used for selecting fonts for the
Text tool .
It also allows you to refresh the list of available fonts, if you add
new ones to your system while GIMP is running.
 3. 7. 1. Activating the Dialog
The “ Fonts ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking” for help on manipulating it.
You can access it:
from an image menu:
Windows → Dockable Dialogs → Fonts ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Fonts ,
from the Tool Options for the Text tool.  If you click on the
“ Font ” button, a Font-selector pops up. In the lower
right corner is a button that, if pressed, brings up the
“ Fonts ” dialog.
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Fonts ” dialog from the image-menu:
Windows → Fonts .
3.7.2. Using the Fonts dialog
The most basic thing you can do is to select a font by clicking on it:
this font will then be used by the Text tool. If instead of clicking and
releasing, you hold down the left mouse button with the pointer
positioned over the font example ( “ Aa ” ), a window showing
a larger text example will pop up ( “ Pack my box with five dozen
liquor jugs ” ).
Grid/List modes Figure 15.62. The Fonts dialog Dialog in Grid View Dialog in List View Tip Ctrl + F
opens a search field.
See View as List; View as Grid
In the Tab menu for the Fonts dialog, you can choose between
View as Grid and
View as List .
In Grid mode, the fonts are laid out in a rectangular array . In
List mode, they are lined up vertically, with each row showing an
example of the appearance of the font ( “ Aa ” ),
followed by the name of the font .
Refresh font list
Pressing this button at the bottom of the dialog causes the system
font list to be rescanned . This may be useful if you add new fonts
while GIMP is running, and want to make them accessible for the
Text tool. You can also cause the font list to be rescanned by
right-clicking in the font display, and selecting “ Rescan
Font List ” from the menu that pops up (it is actually the
only option in the menu).
Tip
You can change the size of the font previews in the dialog using
the “ Preview Size ” submenu of the dialog's Tab menu.
3.6. Tagging 4. Image Management Related Dialogs  Report an error in Bugzilla  Part III. Function Reference Part III. Function Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Part III. Function Reference Table of Contents 14. Tools 1. The Toolbox 1.1. Introduction 1.2. Tool Icons 1.3. Color and Indicator Area 1.4. Tool Options 2. Selection Tools 2.1. Common Features 2.2. Rectangle Selection 2. 3. Ellipse Selection 2.4. Free Selection (Lasso) 2.5. Fuzzy selection (Magic wand) 2. 6. Select By Color 2.7. Intelligent Scissors 2. 8. Foreground Select 3. Paint Tools 3.1. Common Features 3.2. Dynamics 3.3. Brush Tools (Pencil, Paintbrush, Airbrush) 3.4. Bucket Fill 3. 5. Blend 3.6. Pencil 3.7. Paintbrush 3.8. Eraser 3.9. Airbrush 3.10. Ink 3.11. Clone 3.12. Heal 3.13. Perspective Clone 3. 14. Blur/Sharpen 3.15. Smudge 3.16. Dodge/Burn 4. Transform Tools 4.1. Common Features 4.2. Align 4.3. Move 4.4. Crop 4.5. Rotate 4.6. Scale 4.7. Shear 4.8. Perspective 4.9. Flip 4.10. The Cage Tool 5. Color Tools 5.1. Overview 5.2. Color Balance 5. 3. Hue-Saturation 5.4. Colorize 5.5. Brightness-Contrast 5. 6. Threshold 5.7. Levels 5.8. Curves 5.9. Posterize 5.10. Desaturate 6. Other 6.1. Overview 6.2. Paths 6.3. Color Picker 6.4. Zoom 6.5. Measure 6.6. Text 6.7. GEGL Operation 15. Dialogs 1. Dialog Introduction 2. Image Structure Related Dialogs 2.1. Layers Dialog 2.2. Channels Dialog 2.3. Paths Dialog 2.4. Colormap Dialog 2. 5. Histogram dialog 2.6. Navigation Dialog 2.7. Undo History Dialog 3. Image-content Related Dialogs 3.1. FG/BG Color Dialog 3.2. Brushes Dialog 3.3. Patterns Dialog 3.4. Gradients Dialog 3. 5. Palettes Dialog 3.6. Tagging 3.7. Fonts Dialog 4. Image Management Related Dialogs 4.1. Buffers Dialog 4.2. Images Dialog 4.3. Document History Dialog 4.4. Templates Dialog 5. Misc. Dialogs 5.1. Tool Presets Dialog 5.2. Tool Preset Editor 5. 3. Device Status Dialog 5.4. Error Console 5. 5. Save File 5. 6. Export File 5.7. Sample Points Dialog 5.8. Pointer Dialog 16. Menus 1. Introduction to Menus 1.1. The Image Menu Bar 1.2. Context Menus 1.3. Tear-off menus 1.4. Tab menus 2. The “ File ” Menu 2.1. Overview 2.2. New 2.3. Create 2.4. Open 2.5. Open as Layers 2. 6. Open Location 2.7. Open Recent 2. 8. Save 2.9. Save as 2.10. Save a Copy 2.11. Revert 2.12. Export 2.13. Export As... 2.14. Create Template 2.15. Print 2.16. Close 2.17. Close all 2.18. Quit 3. The “ Edit ” Menu 3.1. “ Edit ” Menu Entries 3.2. Undo 3.3. Redo 3.4. Fade 3.5. Undo History 3. 6. Cut 3.7. Copy 3.8. Copy Visible 3.9. Paste 3.10. Paste Into 3.11. Paste as 3.12. Buffer 3.13. Clear 3.14. Fill with FG Color 3.15. Fill with BG Color 3.16. Fill with Pattern 3.17. Stroke Selection 3.18. Stroke Path 3.19. The “ Preferences ” Command 3.20. Keyboard Shortcuts 3.21. Modules 3.22. Units 4. The “ Select ” Menu 4. 1. Introduction to the “ Select ” Menu 4.2. Select All 4. 3. None 4.4. Invert 4.5. Float 4.6. By Color 4.7. From Path 4. 8. Selection Editor 4.9. Feather 4.10. Sharpen 4.11. Shrink 4.12. Grow 4.13. Border 4.14. Distort 4.15. Rounded Rectangle 4.16. Toggle QuickMask 4.17. Save to Channel 4.18. To Path 5. The “ View ” Menu 5. 1. Introduction to the “ View ” Menu 5.2. New View 5. 3. Dot for Dot 5.4. Zoom 5.5. Shrink Wrap 5. 6. Full Screen 5.7. Navigation Window 5. 8. Display Filters 5.9. Show Selection 5.10. Show Layer Boundary 5.11. Show Guides 5.12. Show Grid 5.13. Show Sample Points 5.14. Snap to Guides 5.15. Snap to Grid 5.16. Snap to Canvas 5.17. Snap to Active Path 5.18. Padding Color 5.19. Show Menubar 5.20. Show Rulers 5.21. Show Scrollbars 5.22. Show Statusbar 6. The “ Image ” Menu 6.1. Overview 6.2. Duplicate 6.3. Mode 6.4. RGB mode 6. 5. Grayscale mode 6. 6. Indexed mode 6.7. Transform 6.8. Flip Horizontally; Flip Vertically 6.9. Rotation 6.10. Guillotine 6.11. Canvas Size 6.12. Fit Canvas to Layers 6.13. Fit Canvas to Selection 6.14. Print Size 6.15. Scale Image 6.16. Crop to Selection 6.17. Autocrop Image 6.18. Zealous Crop 6.19. Merge Visible Layers 6.20. Flatten Image 6.21. Align Visible Layers 6. 22. Guides 6.23. New Guide 6.24. New Guide (by Percent) 6.25. New Guides from Selection 6.26. Remove all guides 6.27. Configure Grid 6.28. Image Properties 7. The “ Layer ” Menu 7. 1. Introduction to the “ Layer ” Menu 7.2. New Layer 7. 3. New Layer Group 7.4. New From Visible 7.5. Duplicate layer 7.6. Anchor layer 7.7. Merge Down 7. 8. Delete Layer 7.9. The Text Commands of the Layer Menu 7.10. Discard Text Information 7.11. “ Stack ” Submenu 7.12. Select Previous Layer 7.13. Select Next Layer 7.14. Select Top Layer 7.15. Select Bottom Layer 7.16. Raise Layer 7.17. Lower Layer 7.18. Layer to Top 7.19. Layer to Bottom 7.20. The “ Reverse Layer Order ” command 7.21. The “ Mask ” Submenu 7.22. Add Layer Mask 7.23.
Apply Layer Mask
7.24. Delete Layer Mask 7.25. Show Layer Mask 7.26. Edit Layer Mask 7.27. Disable Layer Mask 7. 28. Mask to Selection 7.29. Add Layer Mask to Selection 7.30. Subtract Layer Mask from Selection 7. 31. Intersect Layer Mask with Selection 7.32.
The “ Transparency ” Submenu of the “ Layer ” menu
7.33. Add Alpha Channel 7.34. Remove Alpha Channel 7.35. Color to Alpha 7.36. Semi-flatten 7.37. Threshold Alpha 7.38. Alpha to Selection 7.39. Add Alpha channel to Selection 7.40. Subtract from Selection 7.41. Intersect Alpha channel with Selection 7.42. The “ Transform ” Submenu 7.43. Flip Horizontally 7.44. Flip Vertically 7.45. Rotate 90° clockwise 7.46. Rotate 90° counter- clockwise 7.47. Rotate 180° 7.48. Arbitrary Rotation 7.49. Offset 7.50. Layer Boundary Size 7.51. Layer to Image Size 7.52. Scale Layer 7.53. Crop to Selection 7.54. Autocrop Layer 8. The “ Colors ” Menu 8. 1. Introduction to the “ Colors ” Menu 8.2. Colors Tools 8. 3. Invert 8.4. Value Invert 8. 5. Use GEGL 8. 6. The “ Auto ” Submenu 8.7. Equalize 8.8. White Balance 8.9. Color Enhance 8.10. Normalize 8.11. Stretch Contrast 8.12. Stretch HSV 8.13. The “ Components ” Submenu 8.14. Channel Mixer 8.15. Compose 8.16.
Decompose
8.17. Recompose 8.18. The “ Map ” Submenu 8.19. Rearrange Colormap 8.20. Set Colormap 8.21. Alien Map 8.22. Color Exchange 8.23. Gradient Map 8.24. Palette Map 8.25. Rotate Colors 8.26. Sample Colorize 8.27. The “ Info ” Submenu 8.28. Histogram 8.29. Border Average 8.30. Colorcube Analysis 8.31. Smooth Palette 8.32. The Color Filters 8.33. Colorify 8.34. Color to Alpha 8.35. Filter Pack 8.36. Hot 8.37. Max RGB 8.38. Retinex 9. The “ Tools ” Menu 9. 1. Introduction to the “ Tools ” Menu 10. The “ Filters ” Menu 10. 1. Introduction to the “ Filters ” Menu 10.2. Repeat Last 10. 3. Re-show Last 10.4. Reset All Filters 10.5. The “ Python-Fu ” Submenu 10.6. The “ Script-Fu ” Submenu 11. “ Windows ” Menu 12. The “ Help ” Menu 12. 1. Introduction to the “ Help ” Menu 12.2. Help 12.3. Context Help 12.4. Tip of the Day 12.5. About 12.6. Plug-In Browser 12.7. The Procedure Browser 12.8. GIMP online 17. Filters 1. Introduction 1.1. Preview 2. Blur Filters 2.1. Introduction 2.2. Blur 2.3. Gaussian Blur 2.4. Selective Gaussian Blur 2.5. Motion Blur 2. 6. Pixelise 2.7. Tileable Blur 3. Enhance Filters 3.1. Introduction 3.2. Antialias 3.3. Deinterlace 3.4. Despeckle 3.5. Destripe 3.6. NL Filter 3.7. Red Eye Removal 3.8. Sharpen 3.9. Unsharp Mask 4. Distort Filters 4.1. Introduction 4.2. Blinds 4.3. Curve Bend 4.4. Emboss 4.5. Engrave 4.6. Erase Every Other Row 4.7. IWarp 4.8. Lens Distortion 4. 9. Mosaic 4.10. Newsprint 4.11. Page Curl 4. 12. Polar Coords 4. 13. Ripple 4.14. Shift 4.15. Value Propagate 4. 16. Video 4.17. Waves 4.18. Whirl and Pinch 4.19. Wind 5. Light and Shadow Filters 5.1. Introduction 5.2. Gradient Flare 5. 3. Lens Flare 5.4. Lighting Effects 5. 5. Sparkle 5.6. Supernova 5.7. Drop Shadow 5. 8. Perspective 5.9. Xach-Effect 5. 10. Apply Lens 5.11. Glass Tile 6. Noise Filters 6.1. Introduction 6.2. HSV Noise 6. 3. Hurl 6.4. Pick 6.5. RGB Noise 6. 6. Slur 6.7. Spread 7. Edge-Detect Filters 7. 1. Introduction 7.2. Difference of Gaussians 7.3. Edge 7.4. Laplace 7.5. Neon 7.6. Sobel 8. Generic Filters 8.1. Introduction 8.2. Convolution Matrix 8. 3. Dilate 8.4. Erode 9. Combine Filters 9.1. Introduction 9.2. Depth Merge 9.3. Film 10. Artistic Filters 10.1. Introduction 10.2. Apply Canvas 10. 3. Cartoon 10.4. Clothify 10.5. Cubism 10.6. GIMPressionist 10.7. Oilify 10.8. Photocopy 10.9. Predator 10.10. Softglow 10.11. Van Gogh (LIC) 10.12. Weave 11. Decor Filters 11.1. Introduction 11.2. Add Bevel 11. 3. Add Border 11.4. Coffee Stain 11. 5. Fuzzy Border 11. 6. Old Photo 11.7. Round Corners 11. 8. Slide 11.9. Stencil Carve 11.10. Stencil Chrome 12. Map Filters 12.1. Introduction 12.2. Bump Map 12. 3. Displace 12.4. Fractal Trace 12. 5. Illusion 12.6. Make Seamless 12.7. Map Object 12. 8. Paper Tile 12. 9. Small Tiles 12. 10. Tile 12.11. Warp 13. Rendering Filters 13.1. Introduction 13.2. Difference Clouds 13. 3. Fog 13.4. Plasma 13.5. Solid Noise 13. 6. Flame 13.7. IFS Fractal 13. 8. Checkerboard 13.9. CML Explorer 13. 10. Diffraction Patterns 13. 11. Grid 13.12. Jigsaw 13.13. Maze 13.14. Qbist 13.15. Sinus 13.16. Circuit 13.17. Fractal Explorer 13. 18. Gfig 13.19. Lava 13.20. Line Nova 13.21. Sphere Designer 13.22. Spyrogimp 14. Web Filters 14.1. Introduction 14.2. ImageMap 14.3. Semi-Flatten 14.4. Slice 15. Animation Filters 15.1. Introduction 15.2. Blend 15.3. Burn-In 15.4. Rippling 15.5. Spinning Globe 15. 6. Waves 15.7. Optimize 15.8. Playback 16. Alpha to Logo Filters 16.1. Introduction 16.2. 3D Outline 16. 3. Alien Glow 16.4. Alien Neon 16. 5. Basic I & II 16.6. Blended 16.7. Bovination 16.8. Chalk 16.9. Chip Away 16. 10. Chrome 16.11. Comic Book 16. 12. Cool Metal 16. 13. Frosty 16.14. Glossy 16.15. Glowing Hot 16. 16. Gradient Bevel 16. 17. Neon 16.18. Particle Trace 16.19. Textured I. Keys and Mouse Reference Help —
Key reference for Help menu
Tools —
Key reference for the Tools menu
File —
Key reference for the File menu
Dialogs —
Key reference for Dockable Dialogs submenu
View —
Key reference for View menu
Edit —
Key reference for Edit menu
Layer —
Key reference for Layer menu
Select —
Key reference for Select menu
Filters —
Key reference for Filters menu
Zoom tool —
Key reference for the Zoom tool submenu
3.7. Your script and its working Chapter 14. Tools
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Chapter 4. Getting Unstuck Chapter 4. Getting Unstuck Part I. Getting Started  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 4. Getting Unstuck Table of Contents 1. Getting Unstuck 1.1. Stuck! 1.2. Common Causes of GIMP Non-Responsiveness 1. Getting Unstuck 1.1. Stuck!
All right, okay: you're stuck. You're trying to use one of the tools on
an image, and nothing is happening, and nothing you try makes any
difference. Your fists are starting to clench, and your face is starting
to feel warm. Are you going to have to kill the program, and lose all
your work? This sucks!
Well, hold on a second. This happens pretty frequently, even to people
who've used GIMP for a long time, but generally the
cause is not so hard
to figure out (and fix) if you know where to look. Lets be calm, and
go through a checklist that will probably get you GIMPing happily again.
1.2. Common Causes of GIMP Non-Responsiveness 1. 2.1. There is a floating selection Figure 4.1.
Layers dialog showing a floating selection.
How to tell:
If there is a floating selection , many actions are impossible
until the floating section is anchored.
To check, look at the Layers dialog (making
sure it's set to the image you're working on) and see whether the
top layer is called “ Floating Selection ” .
How to solve:
Either anchor the floating selection, or convert it into an
ordinary (non-floating) layer. If you need help on how to do this,
see
Floating Selections
.
1.2.2. The selection is hidden Figure 4.2. Unstuck show selection menu
In the View menu, make sure that "Show Selection" is checked.
How to tell:
If this is the problem, merely reading this will already have made
you realize it, probably, but to explain in any case: sometimes
the flickering line that outlines the selection is annoying
because it makes it hard to see important details of the image, so
GIMP gives you the option of hiding the selection,
by unchecking
Show Selection
in the View
menu. It is easy to forget that you have done this, though.
How to fix: If this
hasn't rung any bells, it isn't the problem, and if it has,
you probably know how to fix it, because it doesn't happen
unless you explicitly tell it to; but anyway: just go to
the View menu for the image and, if
Show Selection is
unchecked, click on it..
1.2.3. You are acting outside of the selection Figure 4.3. Unstuck select all
Click “ All ”
in the Select menu to make sure that everything is selected.
How to fix:
If doing this has destroyed a selection that you wanted to keep, hit
Ctrl + Z
(undo) a couple of times to restore it, and then we'll figure
out what the problem is. There are a couple of possibilities. If you
couldn't see any selection, there may have been a very tiny one, or
even one that contained no pixels. If this was the case, it surely is
not a selection that you wanted to keep, so why have you gotten this
far in the first place? If you can see a selection but thought you
were inside it, it might be inverted from what you think. The easiest
way to tell is to hit the Quick Mask button: the selected area will be
clear and the unselected area will be masked. If this was the problem,
then you can solve it by toggling Quick Mask off and choosing Invert
in the Select menu.
1.2.4. The active drawable is not visible Figure 4.4. Unstuck layer invisibility
Layers dialog with visibility off for the active layer.
How to tell:
The Layers dialog gives you ability to toggle the visibility of
each layer on or off. Look at the Layers dialog , and see if
the layer you are trying to act on is active (i.e., darkened) and
has an eye symbol to the left of it. If not, this is your problem.
How to fix:
If your intended target layer is not active, click on it in the Layers
dialog to activate it. (If none of the layers are active, the
active drawable might be a channel -- you can look at the Channels tab
in the Layers dialog to see. This does not change the solution,
though.) If the eye symbol does not appear, click in the Layers dialog
at the left edge to toggle it: this should make the layer visible. See
the Help section for the
Layers Dialog
if you need more help.
1.2.5. The active drawable is transparent Figure 4.5. Unstuck layer transparency
Layers dialog with opacity set to zero for the active layer.
How to tell:
When the opacity is set 0 on the layer, you cannot see anything which
you draw on it. Look the Opacity slider,
and see which side the slider placed at. If it is at the leftmost side,
that is your problem.
How to fix: Move the slider.
1.2.6. You are trying to act outside the layer How to tell:
In GIMP , layers don't need to have the same
dimensions as the
image: they can be larger or smaller. If you try to paint outside
the borders of a layer, nothing happens. To see if this is
happening, look for a black-and-yellow dashed rectangle that does
not enclose the area you're trying to draw at.
How to fix:
You need to enlarge the layer. There are two commands at the bottom of
the Layer menu that will let you do this: Layer to Image Size, which
sets the layer bounds to match the image borders; and Layer Boundary
Size, which brings up a dialog that allows you to set the layer
dimensions to whatever you please.
1.2.7. The image is in indexed color mode. How to tell: GIMP can handle
three different color modes:
RGB(A), Indexed and Grayscale .
The indexed colormode uses a colormap,
where all used colors on the image are indexed. The
color picker in
GIMP however, let you choose RGB colors.
That means, if you try to paint with a different color than
it is indexed in the colormap, you end up in very
undetermined results (e.g. it paints with the wrong color or
you can't paint).
How to fix: Always use the
RGB Color mode to paint on images. You can verify and select
another color mode from the
Mode menuitem in the
Image menu.
5.2. Examples Part II.
How do I Become a GIMP Wizard?
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3. 4. Gradients Dialog 3.4. Gradients Dialog 3. Image-content Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 4. Gradients Dialog Figure 15.39. The screenshot illustrates the Gradients dialog
The “ Gradients ” dialog offers a gradient palette which is
used to select a gradient — a set of colors arranged in a linear
scale — for use with the
Blend tool and numerous
other operations. It also gives you access to several functions for
manipulating gradients. You can select a gradient by clicking on it in
the list : it will then be shown in the Brush/Pattern/Gradient area of
the Toolbox. A few dozen nice gradients come pre-installed with GIMP.
You can create more using the
Gradient Editor .
General information about gradients and how they are used in GIMP can be
found in the Gradients
section.
The first five gradients are particular: they reproduce the gradient
between Foreground and background colors of toolbox in different ways.
FG to BG (Hardedge) : only black and white with a
sharp limit.
FG to BG (HSV clock-wise/counter-clockwise Hue) :
all hues in the color circle between the Foreground and the
background color, clockwise or counter-clockwise.
FG to BG (RGB) : default gradient, between the
Foreground and the background colors of the Toolbox, in the RGB mode.
FG to Transparent : only uses one color (the
Foreground color) from complete opacity to complete transparency.
This gradient is very useful when you work with softly blended
collages or fog effects.
 3. 4. 1. Activating the Dialog
The “ Gradients ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking”
for help on manipulating it.
You can access it:
from an image menu:
Windows → Dockable Dialogs → Gradients ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Gradients ,
from the Toolbox, by clicking on the current gradient in the
Brush/Pattern/Gradient area,
From the image by using the Ctrl + G shortcut. 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Gradients ” dialog from the image-menu:
Windows → Gradients .
3.4.2. Using the “ Gradients ” dialog
The most basic, and most commonly used, operation with the dialog is
simply to click on one of the gradients in the scrollable list, in order
to make it GIMP's current gradient, which will then be used by any
operation that involves a gradient.
If you double-click
on a gradient, you open the Gradient Editor where you will be able to
edit its name. Note, however, that you are only allowed to change the
names of gradients that you have created yourself , not the ones that
come pre-installed with GIMP. If you try to rename a pre-installed
gradient, you will be able to edit the name, but as soon as you hit
return or click somewhere else, the name will revert to its original
value. It is a general rule that you cannot alter the resources that
GIMP pre-installs for you: brushes, patterns, gradients, etc; only ones
that you create yourself.
Grid/List modes
In the Tab menu , you can choose between View as
Grid and View as List .
In Grid mode, the gradients are laid out in a rectangular
array . They look quite dazzling when viewed this way, but it is
not very easy to pick the one you want, because of visual
interference from the neighboring ones. In List mode, the
more usable default, the gradients are lined up vertically, with
each row showing its name.
In the Tab menu, the option Preview Size
allows you to adapt the size of gradient previews to your
liking.
The buttons at the bottom of the dialog allow you to operate on
gradients in several ways:
Edit Gradient
This button activates the
Gradient Editor .
New Gradient
This creates a new gradient, initialized as a simple grayscale,
and activates the Gradient Editor so that you can alter it.
Gradients that you create are automatically saved in the
gradients
folder of your personal GIMP directory , from which they are
automatically loaded when GIMP starts. (You can change this
folder, or add new ones, using the Preferences dialog.)
Duplicate Gradient
This creates a copy of the currently selected gradient. You will
be able to edit the copy even if you cannot edit the original.
Delete Gradient
This removes all traces of the gradient, if you have permission to
do so. It asks for confirmation before doing anything.
Refresh Gradients
If you add gradients to your personal
gradients
folder by some means other than this dialog, this button causes
the list to be reloaded, so that the new entries will be
available .
The functions performed by these buttons can also be accessed from the
dialog pop-up menu, activated by right-clicking anywhere in the
gradient list, or via Gradient Menu in the
Tab menu:
Figure 15. 40. The Gradients Menu
The gradient menu also gives you some additional functions:
Save as POV-Ray...
This allows you to save the gradient in the format used by
the POV-Ray 3D ray-tracing
program.
Copy Gradient Location
This command allows you to copy the gradient file location to
the clipboard. You can then use it in a text editor.
Custom Gradient...
This command creates a sample image filled with the selected
gradient. You can select width and height of the image as well as
the gradient direction in the dialog window.
Save as CSS
The CSS (Cascading Style Sheets) language is used to format the
display of HTML and XML files, for instance background color, font
size... and background gradient. The "CSS Save" plugin is a CSS3
linear gradient generator that allows you to save a CSS3
code snippet, containing the gradient data for a given GIMP
gradient. This code snippet is a text file: you can copy-paste it to
the stylesheet related to your HTML file, to get a gradient
background on opening the HTML file in Firefox, Chrome or Safari web
navigators. This CSS3 code snippet can also be used as a gradient in
SVG files.
Here is an example of code snippet, got using the Blue Green
gradient:
A CSS snippet created with Save as CSS.
background-image: linear-gradient( top, rgb(0,123,255) 0%, rgb(72,226,255) 56%,
rgb(0,255,161) 100%);
background-image: - moz-linear-gradient(center top, rgb(0,123,255) 0%,rgb(72,
226,255) 56%,rgb(0,255,
161) 100%);
background-image: - webkit-gradient(linear, left top, left bottom,
color-stop(0.000, rgb(0,123,255)),color-stop(0.566, rgb(72,226,255)),
color-stop(1.000, rgb(0,255,161)));
3.4.2.1. Tagging
You can use tags to reorganize the gradients display.
See Section 3.6, “Tagging” .
3. 4.3. The Gradient Editor Figure 15.41. The gradient editor
The Gradient Editor allows you to edit the colors in a gradient . It can
only be used on gradients you have created yourself (or on a copy of a
system gradient ), not on system gradients that come pre-installed with
GIMP. This is a sophisticated tool that may take a bit of effort to
understand. The concept behind it is that a gradient can be decomposed
into a series of adjoining segments ,
with each segment consisting of a smooth transition from the color on
the left edge to the color on the right edge. The Gradient Editor allows
you to pack together any number of segments, with any colors you want for
the left and right edges of each segment, and with several options for the
shape of the transition from left to right.
3.4.3. 1. How to Activate the Gradient Editor
You can activate the Gradient Editor in several ways:
by double-clicking on the gradient stripe in the Gradient dialog,
from the context menu you get by right clicking on the selected
gradient name,
by clicking on the Edit gradient
button in the Gradient Dialog,
from the Gradient Menu you get by clicking on
in the Gradient Dialog.
3.4.3.2. Display Name
In the name area, you have the tab menu button (the small
triangle).
The Gradient Preview Window
Below the name, you see the current result of your work if the
Instant update option is checked; else,
changes will appear only when you release the mouse button .
If you simply move the mouse pointer on this display, it works
somewhat as a color-picker. Values of the pointed pixel are
displayed in a rather odd way. Position
is a number given to 3 decimal places, from 0.000 on the left to
1.000 on the right of the whole gradient.
RGB, HSV, Intensity and Opacity
are also a ratio...
If you click-n-drag on display, then only position and RGB data
are displayed. But they are passed on to the Foreground color in
the Toolbox and to the four first gradients of the list ( by
pressing the Ctrl key , the Color is sent to the
Background color of the Toolbox).
Range Selection/Control Sliders
Below the gradient display, you see a set of black and white
triangles lined up in row which allow you to adjust endpoints
and midpoints in the gradient preview. A
segment is the space between two consecutive
black triangles. Inside each segment is a
white triangle, which is used to “ warp ” the colors
in the segment, in the same way that the middle slider
in the Levels tool warps the colors there. You can select a
segment by clicking between the two black triangles that define
it. It turns from white to blue. You can select a range of
segments by shift-clicking on them.
The selected range always consists of a set of
consecutive
segments, so if you skip over any when shift-clicking, they will
be included automatically. If “ Instant update ”
is checked, the display is updated immediately after any slider
movement; if it is unchecked, updates only occur when you release
the mouse button .
You can move sliders, segments and selections. If you simply
click-n-drag a slider ,
you only move the corresponding transition. By
click-n-drag on a segment
you can move this segment up to the next triangle. By
Shift+ click-n-drag on a segment /selection ,
you can move this segment/selection and compress/ dilate next
segments.
Scrollbar
Below the sliders is a scrollbar. This only comes into play if you
zoom in using the buttons at the bottom .
Feedback Area
Below, a color swatch shows the color pointed by the mouse
cursor. Informations about this color and helpful hints or
feedback messages may appear here.
Buttons
At the bottom of the dialog appear five buttons:
Save
Clicking this button causes the gradient, in its current
state, to be saved in your personal gradients
folder, so that it will automatically be loaded the next
time you start GIMP .
Revert
Clicking this button undoes all of your editing. (However,
at the time this is being written, this function is not yet
implemented.)
Zoom Out
Clicking this button shrinks the gradient display
horizontally.
Zoom In
Clicking this button expands the gradient display
horizontally. You can then use the scrollbar to pan the
display left or right.
Zoom All
Clicking this button resizes the display horizontally so
that it fits precisely into the window.
3.4.3.3. The Gradient Editor pop-up Menu Figure 15.42. The Gradient Editor pop-up menu
You can access the Gradient Editor menu either by right-clicking on the
gradient display, or by choosing the top item in the dialog's tab menu.
The menu allows you to edit endpoint's color (set the left and right
edge colors for each segment), blend colors, select a color model and
edit segments. This editor works only with custom gradients or a copy
of a system gradient .
The following commands can be found in the menu: Editing endpoint's color Left/Right color type This command opens a submenu: Figure 15.43. The Left/Right color type sub-menu
This submenu allows you to select the endpoint color from the
toolbox foreground and background colors.
Whenever you change the foreground or background color , this
endpoint color may be changed as well. The alternative is to
select a Fixed endpoint color.
Left [Right] Endpoint's Color
These options allow you to choose a color for the respective
endpoint using a Color Editor.
Note
This command is related to the previous one and becomes
inactive if you have selected any other value than
Fixed for the corresponding Left
[Right] Color Type.
Load Left [Right] Color From Figure 15.44. The “ Load Color From ” submenu
These options give you a number of alternative ways of assigning
colors to the endpoints. From the submenu you can choose (assuming
we're dealing with the left endpoint):
Left Neighbor's Right Endpoint
This choice will cause the color of the right endpoint of
the segment neighboring on the left to be assigned to the
left endpoint of the selected range .
Right Endpoint
This choice will cause the color of the right endpoint of
the selected range to be assigned to the left endpoint .
FG/BG color
This choice causes GIMP's current foreground or background
color , as shown in the Toolbox , to be assigned to the
endpoint. Note that changing foreground or background color
later will not change the endpoint's color.
RGBA slots
At the bottom of the menu are
10 “ memory slots ” . You can assign colors to
them using the “ Save ” menu option described
below. If you choose one of the slots, the color in it will
be assigned to the endpoint.
Save Left [Right] Color To
These options cause the color of the endpoint in question to be
assigned to the “ memory slot ” selected from the
submenu.
Click and drag colors
You can also click and drag a color from the toolbox FG-BG colors
or from a palette
to an endpoint (a black triangle), to set left [right] colors,
to the gradient display area, to add a new endpoint with this
color on both sides.
Blending and coloring functions for segment Blending Function for Segment Figure 15.45. The Blending Function submenu
This option determines the course of the transition from one
endpoint of the range (segment or selection) to the other, by
fitting the specified type of function to the endpoints and
midpoint of the range:
Linear
Default option. Color varies linearly from one endpoint of
the range to the other.
Curved
Gradient varies more quickly on ends of the range than on
its middle.
Sinusoidal
The opposite of the curved type. Gradients varies more
quickly on center of the range than on its ends.
Spherical (increasing)
Gradient varies more quickly on the left of the range than
on its right.
Spherical (decreasing)
Gradient varies more quickly on the right than on the left.
Coloring Type for Segment Figure 15.46. The Coloring Type submenu
This option gives you additional control of the type of transition
from one endpoint to the other: as a line either in RGB space or
in HSV space.
Modifying segments Flip Segment
This option does a right-to-left flip of the selected range
(segment or selection) , flipping all colors and endpoint
locations.
Replicate Segment
This option splits the selected range (segment or selection) into
two parts, each of which is a perfect compressed copy of the
original range.
Split Segment at Midpoint
This option splits each segment in the selected range in into two
segments, splitting at the location of the white triangle.
Split Segment Uniformly
This option is similar to the previous one, but it splits each
segment halfway between the endpoints, instead of at the white
triangle.
Delete Segment
This option deletes all segments in the selected range, (segment
or selection) replacing them with a single black triangle at the
center, and enlarging the segments on both sides to fill the void.
Re-center Segment's midpoint
This option moves the white triangle for each segment in the
selected range to a point halfway between the neighboring black
triangles.
Re-distribute Handles in Segment
This option causes the black and white triangles in the selected
range to be shifted so that the distances from one to the next are
all equal.
Blending colors
These options are available only if more than one segment are
selected.
Blend Endpoints' Colors
This option causes the colors at interior endpoints in the range
to be averaged, so that the transition from each segment to the
next is smooth.
Blend Endpoints' Opacity
This option does the same thing as the previous option, but with
opacity instead of color.
Caution
There is no “ undo ” available within the Gradient Editor,
so be careful!
3.4.3.4. Using example for the Gradient Editor
All these options can seem somewhat boring. Here is an example to clear
ideas:
Open the Gradient Dialog. Click the
New Gradient
.
The Gradient Editor is opened
and shows a gradient from black to white.
Figure 15.47. New gradient
Right click in this new gradient and click the
Split Segment Uniformly . Fix the number of
segments you want.
Figure 15.48. Gradient with three segments
Every segment is limited with two black triangular sliders.
Click a segment to activate it. By pressing the
Shift key , you can select several contiguous
segments.
In the context menu you get by right-clicking in the gradient, set
Left Endpoint Color and
Right Endpoint Color for the selected segment
or segment group.
Figure 15.49. First segment colored
Red has been chosen for left endpoint and yellow for the right
enpoint.
Go on the same way for other segments. Then use the
Blending functions for segment to achieve
various effects.
3.3. Patterns Dialog 3.5. Palettes Dialog
 Report an error in Bugzilla  12.3. Context Help 12.3. Context Help 12. The “ Help ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 3. Context Help
The Context Help command makes the
mouse pointer context-sensitive and changes its shape to a
“ ? ” . You can then click on a window, dialog or menu
entry and GIMP displays help about
it, if it is available. You can also access context help at any time by
pressing the F1 key while the mouse pointer is over
the object you would like help about.
 12.3. 1. Activating the Command
You can access this command from the image menu through
Help → Context Help
or by using the keyboard shortcut
Shift + F1 .  12. 2. Help 12. 4. Tip of the Day  Report an error in Bugzilla 
3. 20. Keyboard Shortcuts 3.20. Keyboard Shortcuts 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 20. Keyboard Shortcuts How to use this command is described in
Section 5 , “Creating Shortcuts to Menu Functions” .
 3. 20. 1. Activate the Command
You can access this command from the image menubar through
Edit → Keyboard Shortcuts… .  3. 19. The “ Preferences ” Command 3.21. Modules
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12. The “Help” Menu 12. The “ Help ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. The “ Help ” Menu 12. 1. Introduction to the “ Help ” Menu Figure 16.208. Contents of the “ Help ” menu
The Help menu contains commands that assist you
while you are working with GIMP .
Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
11. “ Windows ” Menu 12.2. Help
 Report an error in Bugzilla  12. 8. GIMP online 12.8. GIMP online 12. The “ Help ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12.8. GIMP online Figure 16.214. The “ GIMP Online ” submenu of the Help menu
The GIMP online command displays a submenu
which lists several helpful web sites that have to do with various
aspects of GIMP . You can click on one
of the menu items and your web browser will try to connect to the URL.
12.7. The Procedure Browser Chapter 17. Filters
 Report an error in Bugzilla  12.2. Help 12. 2. Help 12. The “ Help ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 2. Help
The Help command displays the
GIMP Users Manual in a browser. You
can set the browser you would like to use in the Help
System section of the Preferences dialog,
as described in Section 1.5, “Help System” .
The browser may be the built-in GIMP help
browser, or it may be a web browser.
Tip
If the help does not seem to work, please verify that the
“ GIMP Users Manual ”
is installed on your system. You can find the most recent help online
[ GIMP-DOCS ] .
 12. 2. 1. Activating the Command
You can access this command from the image menubar through
Help → Help ( F1 ).  12. The “ Help ” Menu 12. 3. Context Help
 Report an error in Bugzilla  2. 5. Histogram dialog 2.5. Histogram dialog 2. Image Structure Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 5. Histogram dialog Figure 15.16. The Histogram dialog
The Histogram dialog shows you information about the statistical
distribution of color values in the active layer or selection . This
information is often useful when you are trying to
color balance
an image. However, the Histogram dialog is purely informational: nothing
you do with it will cause any change to the image. If you want to perform
a histogram-based color correction, use the
Levels tool.
 2. 5. 1. Activating the dialog
The “ Histogram ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking”
for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Histogram .
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Histogram ,
from the image menu:
Colors → Info → Histogram . 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Histogram ” dialog from the image-menu:
Windows → Histogram .
2.5.2. About Histograms
In GIMP, each layer of an image can be decomposed into one or more color
channels: for an RGB image, into R, G, and B channels ; for a grayscale
image, into a single Value channel. Layers that support transparency
have an additional channel, the alpha channel. Each channel supports a
range of intensity levels from 0 to 255 (integer valued). Thus, a black
pixel is encoded by 0 on all color channels; a white pixel by 255 on all
color channels. A transparent pixel is encoded by 0 on the alpha
channel; an opaque pixel by 255.
For RGB images, it is convenient to define a Value “ pseudochannel
” . This is not a real color channel: it does not reflect any
information stored directly in the image. Instead, the Value at a pixel
is given by the equation V = max(R,G,B) .
Essentially, the Value is what you would get at that pixel if you
converted the image to Grayscale mode.
For more information on channels, please consult the
Section 1, “Image Types” .
2.5.3. Using the Histogram dialog
The active layer name is shown at the top of the dialog .
Channel Figure 15.17.
Channel options for an RGB layer with alpha channel
This allows you to select which channel to use. The possibilities
depend on the layer type of the active layer. Here are the entries
you might see, and what they mean:
Value
For RGB and Grayscale images, this shows the distribution of
brightness values across the layer. For a grayscale image,
these are read directly from the image data. For an RGB
image, they are taken from the Value pseudochannel.
For an indexed image, the “ Value ” channel
actually shows the distribution of frequencies for each
colormap index: thus, it is a “ pseudocolor ”
histogram rather than a true color histogram.
Red, Green, Blue
These only appear for layers from RGB images. They show the
distribution of intensity levels for the Red, Green, or Blue
channels respectively.
Alpha
This shows the distribution of opacity levels. If the layer
is completely transparent (alpha = 0) or
completely opaque (alpha = 255), the histogram
will consist of a single bar on the left or right edge.
RGB Figure 15.18.
Combined histograms of R, G, and B channels .
This entry, only available for RGB layers, shows the R, G,
and B histograms superimposed, so that you can see all of
the color distribution information in a single view.
Linear
/ Logarithmic
buttons
Figure 15.19.
The histogram shown at the top, changed to logarithmic mode.
These buttons determine whether the histogram will be displayed
using a linear or logarithmic Y axis. For images taken from
photographs, the linear mode is most commonly useful. For images
that contain substantial areas of constant color, though, a linear
histogram will often be dominated by a single bar, and a
logarithmic histogram will often be more useful.
Range Setting Figure 15.20. Dialog aspect after range fixing.
You can restrict the analysis, for the statistics shown at the
bottom of the dialog , to a limited range of values if you wish.
You can set the range in one of three ways:
Click and drag the pointer across the histogram display area,
from the lowest level to the highest level of the range you
want.
Click and drag the black or white triangles on the slider
below the histogram.
Use the spinbutton entries below the slider (left entry:
bottom of range; right entry: top of range).
Statistics
At the bottom of the dialog some basic statistics are shown
describing the distribution of channel values, restricted to the
selected range:
Mean : the mean value of the interval
in the selected channel.
Std Dev : Standard deviation. Gives an
idea about how homogeneous the distribution of values in the
interval is.
Median : For example, the value of the
fiftieth peak in a 100 peaks interval.
Pixels : The number of pixels in the
active layer or selection .
Count : The number of pixels in a peak
( when you click on the histogram) or in the interval.
Percentile : The ratio between the
number of pixels in the interval and the total number of
pixels in the active layer or selection .
2.4. Colormap Dialog 2. 6. Navigation Dialog
 Report an error in Bugzilla  Chapter 8. Combining Images Chapter 8. Combining Images Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 8. Combining Images Table of Contents 1. Introduction to Layers 1.1. Layer Properties 2. Layer Modes 3. Creating New Layers 4. Layer Groups 1. Introduction to Layers
A good way to visualize a GIMP image is as a stack of
transparencies: in GIMP terminology, each
individual transparency is called a
layer . There is no limit, in principle, to the number
of layers an image can have: only the amount of memory available on the
system. It is not uncommon for advanced users to work with images
containing dozens of layers.
The organization of layers in an image is shown by the Layers dialog,
which is the second most important type of dialog window in
GIMP , after
the Main Toolbox. The appearance of the Layers dialog is shown in the
adjoining illustration. How it works is described in detail in the
Layers Dialog
section, but we will touch on some aspects of it here, in relation to the
layer properties that they display.
Each open image has at any time a single
active drawable . A “ drawable ”
is a GIMP concept that includes layers, but also
several other types of
things, such as channels, layer masks, and the selection mask. (Basically,
a “ drawable ”
is anything that can be drawn on with painting tools). If a layer is
currently active, it is shown highlighted in the Layers dialog , and its
name is shown in the status area of the image window. If not, you can
activate it by clicking on it. If none of the layers are highlighted, it
means the active drawable is something other than a layer.
In the menubar above an image window, you can find a menu called
Layer , containing a number of commands that
affect the active layer of the image . The same menu can be
accessed by right-clicking in the Layers dialog.
1.1. Layer Properties
Each layer in an image has a number of important attributes:
Name
Every layer has a name. This is assigned automatically when the
layer is created, but you can change it . You can change the name
of a layer either by double- clicking on it in the Layers dialog,
or by right-clicking there and then selecting the top entry in the
menu that appears,
Edit Layer Attributes .
Presence or absence of an alpha channel
An alpha channel encodes information about how transparent a layer
is at each pixel. It is visible in the Channel Dialog: white is
complete opacity, black is complete transparency and grey levels
are partial transparencies.
The background layer is particular. If you have just created a
new image, it has still only one layer which is a background
layer. If the image has been created with an opaque Fill type,
this one layer has no Alpha channel . If you add a new layer,
even with an opaque Fill type, an Alpha channel is automatically
created, which applies to all layers apart from the background
layer. To get a background layer with transparency, either you
create your new image with a transparent Fill type, or you use
the
Add an Alpha Channel .
Every layer other than the bottom layer of an image has
automatically an Alpha channel, but you can't see a grayscale
representation of the alpha values. See
Alpha in Glossary for
more information.
Example for Alpha channel. Figure 8.1. Alpha channel example: Basic image
This image has three layers painted with pure 100% opaque
Red, Green, and Blue. In the Channel Dialog, you can see
that an alpha Channel has been added. It is white because
the image is not transparent since there is at least one
100% opaque layer. The current layer is the red one : since
it is painted with pure red, there is no green and no blue
and the corresponding channels are black.
Figure 8.2. Alpha channel example: One transparent layer
The left part of the first layer has been made transparent
(Rectangular selection, Edit/Clear). The second layer,
green, is visible. The Alpha channel is still white , since
there is an opaque layer in this part of the image.
Figure 8. 3. Alpha channel example: Two transparent layers
The left part of the second layer has been made
transparent . The third layer, blue, is visible through the
first and second layers. The Alpha channel is still white ,
since there is an opaque layer in this part of the image.
Figure 8. 4. Alpha channel example: Three transparent layers
The left part of the third layer has been made transparent .
The Alpha channel is still white and the left part of the
layer is white, opaque! The background layer has
no Alpha channel . In this case, the Clear command works
like the Eraser and uses the Background color of Toolbox.
Figure 8.5.
Alpha channel example: Alpha channel added to the Background
We used the
Layer → Transparency → Add Alpha Channel
command, on the Background layer.
Now, the left part of the image is fully transparent and
has the color of the page the image is lying on. The left
part of the Alpha Channel thumbnail is black (transparent)
in the Channel Dialog.
Layer type
The layer type is determined by the image type (see previous
section) and the presence or absence of an alpha channel. These
are the possible layer types:
RGB RGBA Gray GrayA Indexed IndexedA
The main reason this matters is that most filters (in the
Filters
menu ) only accept a subset of layer types, and appear grayed out
in the menu if the active layer does not have an acceptable type.
Often you can rectify this either by changing the mode of the
image or by adding or removing an alpha channel.
Visibility
It is possible to remove a layer from an image,
without destroying it, by clicking on the symbol in the Layers
dialog. This is called “ toggling the visibility ”
of the layer. Most operations on an image treat toggled-off layers
as if they did not exist. When you work with images containing
many layers, with varying opacity, you often can get a better
picture of the contents of the layer you want to work on by hiding
some of the other layers.
Tip
If you Shift -click on the eye symbol, this
will cause all layers except
the one you click on to be hidden.
Linkage to other layers
If you click between the eye icon and the layer thumbnail, you get
a chain icon, which enables you to group layers for operations on
multiple layers ( for example with the Move tool or a transform
tool).
Figure 8.6. Layer Dialog
Red: Linkage to others layers. Green: Visibility.
Size and boundaries
In GIMP , the boundaries of a layer do not
necessarily match the
boundaries of the image that contains it. When you create text,
for example, each text item goes into its own separate layer, and
the layer is precisely sized to contain the text and nothing more.
Also, when you create a new layer using cut-and-paste, the new
layer is sized just large enough to contain the pasted item. In
the image window, the boundaries of the currently active layer are
shown outlined with a black-and-yellow dashed line.
The main reason why this matters is that you cannot do anything to
a layer outside of its boundaries: you can't act on what doesn't
exist. If this causes you problems, you can alter the dimensions
of the layer using any of several commands that you can find near
the bottom of the Layer menu .
Note
The amount of memory that a layer consumes is determined by its
dimensions, not its contents. So, if you are working with large
images or images that contain many layers, it might pay off to
trim layers to the minimum possible size.
Opacity
The opacity of a layer determines the extent to which it lets
colors from layers beneath it in the stack show through. Opacity
ranges from 0 to 100 , with 0 meaning complete transparency, and
100 meaning complete opacity.
Mode
The Mode of a layer determines how colors from the layer are
combined with colors from the underlying layers to produce a
visible result. This is a sufficiently complex, and sufficiently
important, concept to deserve a section of its own, which follows.
See Section 2, “Layer Modes” .
Layer mask
In addition to the alpha channel, there is another way to control
the transparency of a layer: by adding a
layer mask ,
which is an extra grayscale drawable associated with the layer.
A layer does not have a layer mask by default: it must be added
specifically. Layer masks, and how to work with them, are
described much more extensively in the
Layer Mask section.
“ Lock alpha channel ” setting
In the upper left corner of the Layers dialog appears a small
checkbox that controls the “ Lock ”
setting for the transparency of the layer (see the figure below).
If this is checked, then the alpha channel for the layer is
locked, and no manipulation has any effect on it. In particular,
nothing that you do to a transparent part of the layer will have
any effect.
Figure 8.7. Lock Alpha channel 14.2. Creating a Basic Shape 2. Layer Modes
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6. 27. Configure Grid 6.27. Configure Grid 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 27. Configure Grid
The Configure Grid command lets you set
the properties of the grid which you can display over your image
while you are working on it .
The GIMP provides only Cartesian grids.
You can choose the color of the grid lines, and the spacing and offsets
from the origin of the image, independently for the horizontal and
vertical grid lines. You can choose one of five different grid styles.
 6. 27. 1. Activating the Command
You can access this command from the image menubar through
Image → Configure Grid .  6. 27. 2.
Description of the “ Configure Grid ” dialog
Figure 16.84. The “ Configure grid ” dialog Appearance
In the Configure Image Grid dialog, you can set
the properties of the grid which is shown when you turn on the image
grid.
Line style Intersections (dots)
This style, the least conspicuous, shows a simple dot at
each intersection of the grid lines.
Intersections (crosshairs)
This style, the default, shows a plus-shaped crosshair at
each intersection of the grid lines.
Dashed
This style shows dashed lines in the foreground color
of the grid. If the lines are too close together,
the grid won't look good.
Double dashed
This style shows dashed lines , where the foreground
and background colors of the grid alternate.
Solid
This style shows solid grid lines in the
foreground color of the grid.
Foreground and Background colors
Click on the color dwell to select a new color for the grid.
Spacing Width and Height
You can select the cell size of the grid and the unit of
measurement.
Offset Width and Height
You can set the offset of the first cell. The coordinate origin
is the upper left corner of the image . By default , the grid
begins at the coordinate origin, (0,0).
6.26. Remove all guides 6.28. Image Properties
 Report an error in Bugzilla 
6. 5. Grayscale mode 6. 5. Grayscale mode 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 5. Grayscale mode
You can use the Grayscale
command to convert your image to grayscale with 256 levels of gray, from 0
(black) to 255 (white).
 6. 5. 1. Activating the Command
You can access this command from the image menubar through
Image → Mode → Grayscale .  6. 4. RGB mode 6. 6. Indexed mode  Report an error in Bugzilla  6. 6. Indexed mode 6.6. Indexed mode 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 6. Indexed mode
The Indexed command converts your image to
indexed mode. See
indexed colors in the
Glossary for more information about Indexed Color Mode.
 6. 6. 1. Activating the Command
You can access this command from the image menubar through
Image → Mode → Indexed .  6. 6.2. The “ Convert Image to Indexed Colors ” dialog
The Indexed command opens the
Convert Image to Indexed Colors dialog.
Figure 16.54. The “ Convert Image to Indexed Colors ” dialog Colormap Options Generate optimum palette :
This option generates the best possible palette with a
default maximum number of 256 colors (classic GIF format).
You can reduce this
Maximum Number of Colors , although
this may create unwanted effects (color banding) on smooth
transitions. You may be able to lessen the unwanted effects
by using dithering, however.
Use web-optimized palette : use a
palette that is optimized for the web.
Use black and white (1-bit) palette :
This option generates an image which uses only two colors,
black and white.
Use custom palette :
This button lets you select a custom palette from a list.
The number of colors is indicated for each palette. The
“ Web ” palette, with 216 colors, is the
“ web-safe ” palette. It was originally created
by Netscape to
provide colors that would look the same on both Macs and
PCs, and Internet Explorer 3 could manage it. Since
version 4, MSIE handles a 212 color palette. The problem
of color similarity between all platforms has not been
solved yet and it probably never will be. When designing a
web page, you should keep two principles in mind: use light
text on a dark background or dark text on a light
background, and never rely on color to convey information.
Some colors in the palette may not be used if your image
does not have many colors. They will be removed from the
palette if the Remove unused colors from final
palette option is checked.
Dithering Options
Since an indexed image contains 256 colors or less, some colors
in the original image may not be available in the palette. This
may result in some blotchy or solid patches in areas which
should have subtle color changes. The dithering options let you
correct the unwanted effects created by the Palette Options.
A dithering filter tries to approximate a color which is
missing from the palette by instead using clusters of pixels
of similar colors which are in the palette. When seen from a
distance, these pixels give the impression of a new color. See
the Glossary for more information on
dithering .
Three filters (plus “ None ” ) are available. It is
not possible to predict what the result of a particular filter
will be on your image, so you will have to try all of them and
see which works best. The
“ Positioned Color Dithering ” filter is well
adapted to animations.
Figure 16.55. Example: full color, with no dithering
This is an example image with a smooth transition in
RGB Mode.
Figure 16.56. Example: four colors, with no dithering
The same image, after being transformed to four indexed
colors, without dithering.
Figure 16.57. Example: Floyd-Steinberg (normal)
The same image, with four indexed colors and
“ Floyd-Steinberg ( normal) ” dithering.
Figure 16.58. Example: Floyd-Steinberg (reduced color bleeding) The same image, with four indexed colors and
“ Floyd-Steinberg ( reduced color bleeding) ”
dithering.
In a GIF image, transparency is encoded in 1 bit: transparent
or not transparent. To give the illusion of partial
transparency, you can use the Enable dithering of
transparency option. However, the
Semi-flatten
plug-in may give you better results.
Note
You can edit the color palette of an indexed image by using the
Colormap Dialog .
6.5. Grayscale mode 6. 7. Transform
 Report an error in Bugzilla  6. 4. RGB mode 6. 4. RGB mode 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 4. RGB mode
The RGB command converts your image to
RGB mode. See the RGB description in
the Glossary for more information . Normally, you work in this mode,
which is well-adapted to the screen. It is possible to convert an RGB
image to Grayscale or Indexed mode, but be careful: once you have saved
the image, you can no longer retrieve the RGB colors, so you should
work on a copy of your image .
 6. 4. 1. Activating the command
You can access this command from the image menu bar through
Image → Mode → RGB .  6. 3. Mode 6. 5. Grayscale mode  Report an error in Bugzilla  6. 16. Crop to Selection 6.16. Crop to Selection 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 16. Crop to Selection
The Crop to Selection command crops the image to
the boundary of the selection by removing any strips at the edges whose
contents are all completely unselected. Areas which are partially
selected (for example, by feathering) are not cropped. If the selection
has been feathered, cropping is performed on the external limit of the
feathered area. If there is no selection for the image, the menu entry is
disabled and grayed out.
Note
This command crops all of the image layers. To crop just the active
layer, use the Crop Layer
command.
 6. 16. 1. Activate the command
You can access this command on the image menu bar through
Image → Crop to Selection .  6. 15. Scale Image 6. 17. Autocrop Image  Report an error in Bugzilla  4. 2. Images Dialog 4.2. Images Dialog 4. Image Management Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 2. Images Dialog Figure 15.67. The Images dialog
The “ Images ” Dialog displays the list of open images on your
screen ; each of them is represented with a thumbnail. This dialog is
useful when you have many overlapping images on your screen: thus, you
can raise the wanted image to foreground.
 4.2. 1. Activating the dialog
The “ Images ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking” for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Images ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Images . 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Images ” dialog from the image-menu:
Windows → Images .
4.2.2. Using the Images dialog
In multi-window mode, at the top of the dialog , a drop-list of open images
appears if the “ Show Image Selection ” option is checked
in the Tab Menu.
At center, open images appear, as a list or a grid, according to the
selected mode. The current image is highlighted in list mode, outlined
in grid mode. With a double click on an image name, you raise this
image to the foreground of your screen. With a simple click you select
this image so that the buttons of the dialog can act on it.
Grid and List modes, preview size
In the Tab menu for the “ Images ” dialog, you can choose
between View as Grid and
View as List .
In Grid mode, the images are laid out in a rectangular array .
In List mode, they are lined up vertically, with each row showing
a thumbnail of the contents of the image, its name, and its pixel
dimensions.
Tip Ctrl + F
opens a search field.
See View as List; View as Grid You can change the size of the image previews in the dialog using
the “ Preview Size ” submenu of the dialog's Tab menu.
Buttons
Three buttons at the bottom of the dialog allow you to operate on
the selected image. These buttons are present if the “ Show
button bar ” is checked in the tab dialog. You can get the
same commands through the pop menu by right-clicking on the dialog .
Raise this image displays
The selected image appears at the foreground of your screen. If
this image has another view, this view also is raised but
remains behind the original. The same option in the pop-up menu,
that you get by right-clicking , is called “ Raise views
”
Create a new display for this image
Duplicates the image window (not the image) of the selected image.
Delete
This command works only on a image which is loaded without any
window. Though images can be opened by the New Window command,
if the image has been already loaded without window by a
primitive procedure command (such as
gimp-image-new ,
file-png-load , etc.), it can not be
unloaded even if its windows are closed to the last. Then use
this command to close it.
4. Image Management Related Dialogs 4. 3. Document History Dialog  Report an error in Bugzilla  6. 2. Duplicate 6.2. Duplicate 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 2. Duplicate
The Duplicate command creates a new
image which is an exact copy of the current one, with all of its layers,
channels and paths. The GIMP Clipboard and
the History are not affected.
Note
Don't mistake a duplicated image for a new view of this image. In a
View → New View ,
all changes are passed on the original image.
 6. 2. 1. Activating the Command
You can access this command from the image menubar through
Image → Duplicate ,
or by using the keyboard shortcut
Ctrl + D .  6. The “ Image ” Menu 6. 3. Mode
 Report an error in Bugzilla  6. 20. Flatten Image 6.20. Flatten Image 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 20. Flatten Image
The Flatten Image command merges all of the
layers of the image into a single layer with no alpha channel. After
the image is flattened, it has the same appearance it had before. The
difference is that all of the image contents are in a single layer
without transparency. If there are any areas which are transparent
through all of the layers of the original image, the background color
is visible.
This operation makes significant changes to the structure of the image.
It is normally only necessary when you would like to save an image in
a format which does not support levels or transparency (an alpha
channel).
 6. 20. 1. Activate the Command
You can access this command from the image menubar through
Image → Flatten Image .  6. 19. Merge Visible Layers 6. 21. Align Visible Layers  Report an error in Bugzilla  6. 8. Flip Horizontally; Flip Vertically 6. 8. Flip Horizontally; Flip Vertically 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 8. Flip Horizontally; Flip Vertically
You can flip the image, or turn it over like a
card, by using the Flip Horizontally or
Flip Vertically commands.
These commands work on the whole image. To flip a selection, use the
Flip Tool .
To flip a layer, use the functions of the
Layer → Transform
menu or the
Flip Tool .
 6. 8. 1. Activate the Commands
You can access the horizontal flip command from the image menubar
through
Image → Transform → Flip Horizontally .
You can access the vertical flip command from the image menubar
through
Image → Transform → Flip Vertically .  6. 7. Transform 6. 9. Rotation
 Report an error in Bugzilla  6. 22. Guides 6.22. Guides 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 22. Guides Figure 16.81.
The “ Guides ” options of the “ Image ” submenu
The Guides submenu contains various commands
for the creation and removal of guides.
6.22. 1. Activating the Submenu
You can access this submenu from the image menubar through
Image → Guides .
6.22. 2. The Contents of the “ Guides ” Submenu
The Guides submenu contains the
following commands:
Section 6.23, “New Guide” Section 6.24, “New Guide (by Percent)” Section 6.25, “New Guides from Selection” Section 6.26, “Remove all guides” 6.21. Align Visible Layers 6. 23. New Guide
 Report an error in Bugzilla 
6. The “Image” Menu 6. The “ Image ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. The “ Image ” Menu 6. 1. Overview Figure 16.52. The Contents of the “ Image ” Menu
The Image menu contains commands which use
or affect the entire image in some way, not just the active layer or
some other specific part of the image.
Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
5.22. Show Statusbar 6.2. Duplicate
 Report an error in Bugzilla 
6. 19. Merge Visible Layers 6. 19. Merge Visible Layers 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 19. Merge Visible Layers The Merge Visible Layers command merges
the layers which are visible into a single layer. Visible layers are
those which are indicated on the Layers dialog with an
“ eye ” icon .
Note
With this command, the original visible layers disappear. With the
New From
Visible command, a new layer is created at top of the
stack and original visible layers persist.
 6. 19. 1. Activate the Command
You can access this command from the image menubar through
Image → Merge Visible Layers ,
or by using the keyboard shortcut
Ctrl + M .  6. 19. 2.
Description of the “ Layers merge Options ” Dialog
Figure 16.71. The “ Layers Merge Options ” Dialog Final, Merged Layer should be:
Visible layers are the layers which are marked with an
“ eye ” icon in the Layers dialog.
Expanded as necessary :
The final layer is large enough to contain all of the
merged layers. Please note that a layer in
GIMP can be larger than the
image .
Clipped to image :
The final layer is the same size as the image . Remember
that layers in GIMP can be
larger than the image itself. Any layers in the image that
are larger than the image are clipped by this option.
Clipped to bottom layer :
The final layer is the same size as the bottom layer. If
the bottom layer is smaller than some of the visible layers,
the final layer is clipped and trimmed to the size and
position of the bottom layer.
Merge within active group only
This self-explanatory option is enabled when a layer group exists.
Discard invisible layers
When this option is checked , non visible layers are removed from
the layer stack.
Figure 16.72. “ Merge visible layers ” example Three layers; two are visible “ Discard invisible layers ” unchecked
“ Discard invisible layers ” checked 6.18. Zealous Crop 6.20. Flatten Image
 Report an error in Bugzilla  6. 3. Mode 6. 3. Mode 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 3. Mode Figure 16.53.
The “ Mode ” submenu of the “ Image ” menu
The Mode submenu contains commands which
let you change the color mode of the image. There are three modes.
6.3. 1. Activating the Submenu
You can access this submenu from the image menubar through
Image → Mode .
6.3. 2. The Contents of the “ Mode ” Submenu RGB Grayscale Indexed
Assign Color Profile (see
Color management )
Convert to Color Profile (see
Color management )
6.2. Duplicate 6.4. RGB mode
 Report an error in Bugzilla  6. 14. Print Size 6.14. Print Size 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 14. Print Size
You can use the Print Size dialog to change
the dimensions of a printed image and its
resolution . This command does not change the number
of pixels in the image and it does not resample the image. ( If you want
to change the size of an image by resampling it, use the
Scale Image command.)
6.14. 1. Activating the Dialog
You can access this dialog from the image menubar through
Image → Print Size .
6.14.2. Options in the “ Print Size ” Dialog Figure 16. 67. The “ Print Size ” dialog
The output resolution determines the number of pixels used per unit
length for the printed image. Do not confuse the output resolution
with the printer's resolution, which is a printer feature and expressed
in dpi (dots per inch); several dots are used to print a pixel.
When the dialog is displayed, the resolution shown in the boxes is the
resolution of the original image. If you increase the output
resolution, the printed page will be smaller, since more pixels are
used per unit of length. Conversely, and for the same reason,
resizing the image modifies the resolution.
Increasing the resolution results in increasing the sharpness of the
printed page. This is quite different from simply reducing the image
size by scaling it, since no pixels (and no image information) are
removed.
Width; Height
You can set the printing Width and Height by using the
text boxes. You can also choose the units for these values
from the dropdown list.
As soon as you change the Width or the Height, the X and/or
Y resolution values automatically change accordingly. If the
two resolution values remain linked, the relationship of the
width to the height of the image is also automatically
maintained. If you would like to set these values independently
of each other , simply click on the chain symbol to break the
link.
X resolution; Y resolution
You can set the resolution used to calculate the printed
width and height from the physical size of the image , that is ,
the number of pixels in it .
Use the text boxes to change these resolution values.
They can be linked to keep their relationship constant. The
closed chain symbol between the two boxes indicates that the
values are linked together. If you break the link by clicking
on the chain symbol, you will be able to set the values
independently of each other .
6.13. Fit Canvas to Selection 6.15. Scale Image
 Report an error in Bugzilla  6. 28. Image Properties 6.28. Image Properties 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 28. Image Properties The “ Image Properties ” command opens a window that shows
lots of different information for the image.
 6. 28. 1. Activate the Command
You can access this command from the image menubar through
Image → Image Properties ,
or by using the keyboard shortcut
Alt + Return .  6. 28.2. Options The properties window is divided into three tabs. 6.28.2.1. “ Properties ” tab Figure 16.85. “ Properties ” tab Pixel dimensions
Shows the image height and width in pixels, that is, the
physical size of the image .
Print size
Shows the size the image will have when it is printed , in the
current units. This is the logical size of
the image. It depends upon the physical size of the image and
the screen resolution.
Resolution
Shows the print resolution of the image in pixel per inch.
Color space Shows the images color space. File name
Path and name of the file that contains the image.
File size Size of the file that contains the image. File type Format of the file that contains the image. Size in memory
RAM consumption of the loaded image including the images
journal.
This information is also displayed in the image window. The
size is quite different from the size of the file on disk.
That is because the displayed image is decompressed and
because GIMP keeps a copy of the image in
memory for Redo operations.
Undo steps
Number of actions you have performed on the image, that you
can undo. You can see them in the
Undo History dialog.
Redo steps
Number of actions you have undone, that you can redo.
Number of pixels; Number of layers; Number of channels; Number
of paths
Well counted! 6.28.2.2. “ Color profile ” tab Figure 16.86. “ Color profile ” tab
This tab contains the name of the color profile the image is loaded
into GIMP with. Default is the built-in “ sRGB ” profile.
6.28.2.3. “ Comments ” tab Figure 16.87. “ Comments ” tab
This tab allows you to view and edit a comment for the image.
6.27. Configure Grid 7. The “ Layer ” Menu  Report an error in Bugzilla  6. 12. Fit Canvas to Layers 6. 12. Fit Canvas to Layers 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 12. Fit Canvas to Layers
The Fit Canvas to Layers command adapts the
canvas size to the size of the largest layer in the image, in both width
and height.
When you create or open an image, the canvas size is defined as the
image size and remains unchanged if you add new layers. If you add a
layer larger than the canvas, only the area limited by the canvas will be
visible. To show the whole layer, use this command.
 6. 12. 1. Activate the command
You can access this command from the image menubar through
Image → Fit Canvas to Layers .  6. 11. Canvas Size 6. 13. Fit Canvas to Selection
 Report an error in Bugzilla  6. 13. Fit Canvas to Selection 6.13. Fit Canvas to Selection 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 13. Fit Canvas to Selection
The Fit Canvas to Selection command adapts the
canvas size to the size of the selection , in both width and height.
 6. 13. 1. Activate the command
You can access this command from the image menubar through
Image → Fit Canvas to Selection .  6. 12. Fit Canvas to Layers 6. 14. Print Size
 Report an error in Bugzilla  6. 11. Canvas Size 6. 11. Canvas Size 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 11. Canvas Size
The “ canvas ” is the visible area of the image. By default
the size of the canvas coincides with the size of the layers. The
Canvas Size command lets you enlarge or
reduce the canvas size. You can, if you want, modify the size of the
layers. When you enlarge the canvas, you create free space around
the contents of the image. When you reduce it, the visible area is
cropped, however the layers still extend beyond the canvas border.
When you reduce the canvas size, the new canvas appears surrounded with
a thin negative border in the preview. The mouse pointer is a moving
cross: click and drag to move the image against this frame.
 6. 11. 1. Activating the Command
You can access this command from the image menubar through
Image → Canvas Size .  6. 11. 2. Description of the “ Canvas Size ” dialog Figure 16. 60. The “ Canvas Size ” dialog Canvas Size Width; Height
You can set the Width and the
Height of the canvas. The default
units are pixels but you can choose different units, e.g.
percent, if you want to set the new dimensions relative to the
current dimensions. If the Chain to the right of the Width and
Height is not broken, both Width and Height keep the same
relative size to each other. That is, if you change one of the
values, the other one also changes a corresponding amount.
If you break the Chain by clicking on it, you can set
Width and Height separately.
Whatever units you use, information about the size in pixels
and the current resolution are always displayed below the
Width and Height
fields. You cannot change the resolution in the
Canvas Size dialog; if you want to
do that, use the Print
Size dialog .
Offset
The Offset values are used to place the image
(the image, not the active layer) on the canvas. You can see the
size and the content of the canvas in the preview of the dialog
window. When the canvas is smaller than the image , the preview window
shows it in a frame with a thin negative border .
X ; Y
The X and Y specify the
coordinates of the upper left corner of the image relative to the
upper left corner of the canvas . They are negative when the
canvas is smaller than the image . You can place the image in
different ways (of course, the coordinates can't exceed the
canvas borders):
by click-and-dragging the image,
by entering values in the X and
Y text boxes,
by clicking on the small arrow-heads. This increments the
value by one pixel (unit).
And when the focus is on a text box, you can use the
keyboard arrow keys , Up and
Down to change by one pixel (unit), or
PageUp and PageDown to
change the value by 10 pixels (units).
Layers
Before the GIMP-2.4 version, “ Canvas Size ” had no
influence on layer size. To change it, you had to use the
Layer Boundary Size
command . The “ Layers ” option now allows you to
specify how , possibly, layers will be resized. The drop-down list
offers you several possibilities:
Figure 16.61. The Resize layers list None : default option. No layer is
resized, only the canvas is.
All Layers : all layers are resized to
canvas size.
Image-sized layers : only layers with
the same size as the image are sized to canvas size.
All visible layers : only visible
layers, marked with a
icon, in the Layer Dialog, are sized to canvas size.
All linked layers : only linked layers,
marked with a
in the Layer Dialog, are sized to canvas size.
Center
The Center button allows you to center the
image on the canvas. When you click on the Center button ,
the offset values are automatically calculated and displayed in
the text boxes.
Note
When you click on the Resize button,
the canvas is resized, but the pixel information and the drawing
scale of the image are unchanged.
If the layers of the image did not extend beyond the borders of
the canvas before you changed its size, there are
no layers on the part of the canvas that was added by resizing it.
Therefore, this part of the canvas is transparent and displayed
with a checkered pattern, and it is not immediately available for
painting. You can either
flatten
the image, in which case you will get an image with a single layer
that fits the canvas exactly, or you can use the
Layer to Image Size
command to resize only the active layer, without changing any other
layers. You can also create a new layer and fill it with the
background you want. By doing this, you create a
digital “ passe-partout ” (a kind of glass mount
with a removable back for slipping in a photograph).
6.11.3. Example Figure 16.62. Original image
We started with a green background layer 100x100 pixels, which
defines a default canvas with the same size. Then we added a new
red layer 80x80 pixels. The active layer limits are marked with a
black and yellow dotted line. The red layer does not fill the
canvas completely: the unoccupied part is transparent. The
background color in the Toolbox is yellow.
Figure 16.63. Canvas enlarged (layers unchanged)
The canvas has been enlarged to 120x120 pixels. The layers
size remained unchanged. The unoccupied part of the canvas is
transparent .
Figure 16.64. Canvas enlarged (all layers changed)
The canvas has been enlarged to 120x120 pixels. All layers
have been enlarged to the canvas size. The undrawn part is
transparent in the red layer and yellow (background color in
Toolbox) in the green background layer.
6.11.4. What's Canvas Size useful for?
You may want to add some stuff around your image: enlarge canvas size,
add a new layer that will have the same size as the new canvas and
then paint this new layer. That's the converse of cropping.
You can also use this command to crop an image: Figure 16.65. Resizing canvas
Click on the chain next to Width and Height entries to unlink
dimensions. By modifying these dimensions and moving image against
canvas, by trial and error, you can crop the part of the image you
want . Click on the Center button and then on the Resize button.
Figure 16.66. Cropped image Note
The Crop tool is easier to use.
6.10. Guillotine 6.12. Fit Canvas to Layers
 Report an error in Bugzilla  6. 9. Rotation 6. 9. Rotation 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 9. Rotation
You can rotate the image 90° clockwise or counter-clockwise , or rotate
it 180°, by using the rotation commands on the
Transform submenu of the
Image menu. These commands can be used to change
between Portrait and Landscape orientation. They work on the
whole image. If you want to rotate the image at a different angle,
rotate a selection or rotate a layer, use the
Rotate Tool . You can also
rotate a layer by using the
Layer Transform menu.
 6. 9. 1. Activate the Commands
You can access these three commands from the image menubar through
Image → Transform → Rotate 90 degrees CW ,
Image → Transform → Rotate 90 degrees CCW and
Image → Transform → Rotate 180° .  6. 8. Flip Horizontally; Flip Vertically 6. 10. Guillotine
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6. 15. Scale Image 6. 15. Scale Image 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 15. Scale Image
The Scale Image command enlarges or reduces
the physical size of the image by changing the number of pixels it
contains. It changes the size of the contents of the image and resizes
the canvas accordingly.
It operates on the entire image. If your image has layers of different
sizes, making the image smaller could shrink some of them down to nothing,
since a layer cannot be less than one pixel wide or high. If this happens,
you will be warned before the operation is performed.
If you only want to scale a particular layer, use the
Scale Layer command.
Note
If scaling would produce an image larger than the
“ Maximum new image size ” set in the
Environment page of the
Preferences dialog (which has a default of 128 Mb), you are warned and
asked to confirm the operation before it is performed. You may not
experience any problems if you confirm the operation, but you should
be aware that very large images consume a lot of resources and
extremely large images may take more resources than you have,
causing GIMP to crash or not perform well.
 6. 15. 1. Activate the Command
You can access this command from the image menubar through
Image → Scale Image .  6. 15. 2. The “ Scale Image ” Dialog Figure 16. 68. The “ Scale Image ” dialog Image Size
You should keep in mind that an image can be located in one of
four places: in the image file, in RAM after it has been loaded,
on your screen when it is displayed, or on paper after it has been
printed. Scaling the image changes the number of pixels (the
amount of information) the image contains, so it directly affects
the amount of memory the image needs (in RAM or in a file).
However printing size also depends upon the resolution of the
image , which essentially determines how many pixels there will
be on each inch of paper. If you want to change the printing
size without scaling the image and changing the number of pixels
in it , you should use the
Print Size dialog .
The screen size depends not only on the number of pixels, but
also on the screen resolution, the zoom factor and the setting
of the Dot for Dot
option.
If you enlarge an image beyond its original size,
GIMP calculates the missing pixels by
interpolation, but it does not add any new detail. The more you
enlarge an image, the more blurred it becomes. The appearance of
an enlarged image depends upon the interpolation method you
choose. You may improve the appearance by using the
Sharpen filter after you
have scaled an image, but it is best to use high resolution when
you scan, take digital photographs or produce digital images by
other means. Raster images inherently do not scale up well.
You may need to reduce your image if you intend to use it on a web
page. You have to consider that most internet users have
relatively small screens which cannot completely display a large
image. Many screens have a resolution of 1024x768 or even less.
Adding or removing pixels is called “ Resampling ” .
Width; Height
When you click on the Scale
command, the dialog displays the dimensions of the
original image in pixels. You can set the Width and the
Height you want to give to your
image by adding or removing pixels. If the chain icon next
to the Width and Height boxes is unbroken, the Width and
Height will stay in the same proportion to each other. If
you break the chain by clicking on it, you can set them
independently, but this will distort the image.
However, you do not have to set the dimensions in pixels.
You can choose different units from the drop-down menu.
If you choose percent as the units, you can set the image
size relative to its original size. You can also use
physical units, such as inches or millimeters. If you do
that, you should set the X resolution
and Y resolution fields to
appropriate values, because they are used to convert
between physical units and image dimensions in pixels.
X resolution; Y resolution
You can set the printing resolution for the image in the
X resolution
and Y resolution
fields . You can also change the units of measurement by
using the drop-down menu.
Quality
To change the image size, either some pixels have to be removed
or new pixels must be added. The process you use determines the
quality of the result . The Interpolation
drop down list provides a selection of available methods of
interpolating the color of pixels in a scaled image:
Interpolation None :
No interpolation is used. Pixels are simply enlarged
or removed, as they are when zooming. This method is low quality, but very fast.
Linear : This method is relatively
fast, but still provides fairly good results.
Cubic :
The method that produces the best results, but also
the slowest method.
Sinc (Lanczos 3) : New with
GIMP-2.4, this method gives less blur in important
resizings.
Note
See also the Scale tool ,
which lets you scale a layer, a selection or a path .
6.14. Print Size 6.16. Crop to Selection
 Report an error in Bugzilla  Chapter 9. Text Management Chapter 9. Text Management Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 9. Text Management Table of Contents 1. Text Management 2. Text Tool Box 2.1. Text Tool Box Context menu 3. Text 3.1. Embellishing Text 3.2. Adding Fonts 3.3. Font Problems 1. Text Management
Text is managed with the Text tool. This tool creates a new layer containing
the text, above the current layer in the layer dialog, with the size of the
text box . Its name is the beginning of the text.
Figure 9.1. Example of a text item Example of a text item , showing the boundary of the text layer.
(Font: Utopia Bold)
The layer dialog, with the text layer above the layer which was
current.
The Text tool is progressively improved. With GIMP -2.8 ,
you can now edit text directly on canvas. A text tool box has been added
which overlays the canvas above the text box.
As soon as you click on the canvas with the Text tool, you get a closed
text box and a semi-transparent tool box just above.
Text tool options are described in Section 6.6 , “Text” .
The default box mode is “ Dynamic ” , and you can start typing
text at once. The text box will enlarge gradually. Press
Enter to add a new line.
You can also enlarge the text box by
click-and-dragging, as you do with selections. Note that box mode
turns to "Fixed". You also have to press Enter to add
a new line.
To edit text , you must, first, select the
part you want to edit by click-and-drag, or
Shift + arrow key and
then use the options of the Section 2, “Text Tool Box” .
Instead of using the on-canvas text editing, you can use the text editor
dialog described in Section 6.6 .4, “Text Editor” .
You can move the text on the image using
the Move tool: you must click on a character, not on the background.
You can get Unicode characters with
Ctrl + Shift + U
plus hexadecimal Unicode code of the desired char . Please see Section 6.6.4, “Text Editor” .
You can edit the text later , if the text
layer still exists and has not been modified by another tool (see below):
make the text layer active in the Layer
dialog , select the Text tool and click on the text in the image
window.
Managing Text Layer
You can operate on a text layer in the same ways as any other layer,
but doing so often means giving up the ability to edit the text
without losing the results of your work .
To understand some of the idiosyncrasies of text handling, it may help
for you to realize that a text layer contains more information than
the pixel data that you see: it also contains a representation of the
text in a text-editor format. You can see this in the text-editor
window that pops up while you are using the Text tool. Every time you
alter the text, the image layer is redrawn to reflect your changes.
Now suppose you create a text layer, and then operate on it in some
way that does not involve the Text tool: rotate it, for example.
Suppose you then come back and try to edit it using the Text tool. As
soon as you edit the text, the Text tool will redraw the layer,
wiping out the results of the operations you performed in the
meantime.
Because this danger is not obvious, the Text tool tries to protect you
from it. If you operate on a text layer , and then later try to edit
the text, a message pops up, warning you that your alterations will be
undone, and giving you three options:
edit the text anyway; cancel;
create a new text layer with the same text as the existing layer,
leaving the existing layer unchanged.
Figure 9.2. Warning lose modifications Text Editing Context Menu Figure 9.3. Text Editing Context Menu
You get this menu by right-clicking on text. It is somewhat different
from that of the Text Editor dialog.
Cut, Copy, Paste, Delete : these options
concern a selected text. They remain grayed out as long as no text
is selected. “ Paste ” is activated if the clipboard is
full of text.
Open text file : this command opens a file
browser where you can find the wanted text file.
Clear : this command deletes all the text,
selected or not.
Path from text : this command creates a
path from the outlines of the current text. The result is not
evident. You have to open the Path dialog and make path visible.
Then select the Path tool and click on the text. Every letter
is now surrounded with a path component. So you can modify
the shape of letters by moving path control points.
This command is similar to
Layer → Text to Path .
Text along path :
This option is enabled only if a
path exists. When your
text is created, then create or import a path and make it active.
If you create your path before the text, the path becomes
invisible and you have to make it visible in the Path Dialog.
This command is also available from the “ Layer ” menu:
Figure 9.4.
The Text along Path command among text commands in the Layer
menu
This group of options appears only if a text layer exists.
Click on the Text along Path button. The
text is bent along the path. Letters are represented with their
outline. Each of them is a component of the new path that
appears in the Path
dialog . All path options should apply to this new path.
Figure 9.5. “ Text along Path ” example From Left to Right / From Right to Left : fix
the writing direction of your language.
Input Methods : methods are available for some
languages. For example, selecting “ Inuktitut ”
transforms your keyboard into an Inuktitut keyboard, temporarily.
4. Layer Groups 2. Text Tool Box
 Report an error in Bugzilla  6. 7. Transform 6. 7. Transform 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 7. Transform Figure 16.59.
The “ Transform ” submenu of the “ Image ” menu
The items on the Transform submenu transform
the image by flipping it, rotating it or cropping it.  6.7. 1. Activating the Submenu
You can access this submenu from the image menubar through
Image → Transform .  6. 7. 2. The Contents of the “ Transform ” Submenu
The Transform submenu has the following
commands:
Flip Horizontally;
Flip Vertically Rotate 90° clockwise /
counter-clockwise; Rotate 180° Guillotine 6.6. Indexed mode 6.8. Flip Horizontally; Flip Vertically
 Report an error in Bugzilla  3. The QuickMask 3. The QuickMask Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. The QuickMask Figure 7.9. Image with QuickMask enabled
The usual selection tools
involve tracing an outline around an area of interest, which does not
work well for some complex selections. The QuickMask, however, allows
you to paint a selection instead of just tracing its outline.
3.1. Overview
Normally, a selection in GIMP is represented by
“ marching ants ” that trace the selection outline, but there
may be more to a selection than the marching ants show. A
GIMP selection is actually a full-fledged grayscale
channel , covering the image, with pixel values ranging from 0
(unselected) to 255 (fully selected). The marching ants are drawn along
a contour of half-selected pixels. Thus, what the marching ants show you
as either inside or outside the boundary is really just a slice through
a continuum.
The QuickMask is GIMP 's way of showing the full
structure of the selection.
QuickMask also provides the ability to interact with the
selection in new, and substantially more powerful, ways.
Click the small outlined button at the lower left of the image window to
toggle QuickMask on and off. The button switches between QuickMask
mode, and marching ants mode.
You can also use
Select → Toggle QuickMask , or
Shift + Q ,
to toggle between QuickMask and marching ants mode.
In QuickMask mode, the selection is shown as a
translucent screen overlying the image, whose transparency at each pixel
indicates the degree to which that pixel is selected. By default the
mask is shown in red, but you can change this if another mask color
is more convenient. The less a pixel is selected, the more it is
obscured by the mask. Fully selected pixels are shown completely clear.
In QuickMask mode, many image manipulations act on the
selection channel rather than the image itself. This includes, in
particular, paint tools. Painting with white selects pixels, and
painting with black unselects pixels.
You can use any of the paint tools, as well as the bucket
fill and gradient fill tools, in this way. Advanced users of
GIMP learn that “ painting the selection ”
is the easiest and most effective way to delicately manipulate the
image.
Tip
To save a QuickMask selection to a new channel; Make
sure that there is a selection and that QuickMask mode is not
active in the image window. Use
Select → Save to Channel .
to create a new channel in the channel dialog called
“ SelectionMask copy ” (repeating this command
creates “ ..copy#1 ” , “ ...copy#2 ” and
so on...).
Tip
In QuickMask mode, Cut and Paste act on the selection rather
than the image. You can sometimes make use of this as the most
convenient way of transferring a selection from one image to another .
You can learn more on
Selection masks in the
section dedicated to the channel dialog.
2.2. Adding or subtracting selections 3.2. Properties
 Report an error in Bugzilla  3. 2. Properties 3.2. Properties 3. The QuickMask  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Properties
There are two QuickMask properties you can change by right-clicking
on the QuickMask button.
Normally the QuickMask shows unselected areas “ fogged over
” and selected areas “ in clear ” , but you can
reverse this by choosing “ Mask Selected Areas ” instead
of the default “ Mask Unselected Areas ” .
Use “ Configure Color and Opacity ” to open
a dialog that allows you to set these to values other
than the defaults, which are red at 50% opacity.
3. The QuickMask 4. Using QuickMask Mode
 Report an error in Bugzilla  2. 2. Image Window 2.2. Image Window 2. Main Windows  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Image Window GIMP user interface is now available in two modes: multi-window mode
(default), and single-window mode (optional, through
Windows → & gt;Single-Window Mode .
But, if you quit GIMP with this option enabled, GIMP will open in single
mode next time).
In single-window mode, no new window is added: images and dialogs are added
in tabs. Please see Single Window Mode .
When you start GIMP without any image open, the image
window seems to be absent in single-window mode, while, in multi-window
mode, an image window exists, even if no image is open .
We will begin with a brief description of the components that are
present by default in an ordinary image window. Some of the
components can be removed by using commands in the
View menu.
Figure 3.5. The Image Window in Multi-Window Mode Figure 3. 6. The Image Area in Single-Window Mode Note
Despite Single -window Mode, we will use
“ image window ” for “ image area ” .
Title Bar:
The Title Bar in an image window without an image displays
“ GNU Image Manipulating Program ” .
An image window with an image displays the image name
and its specifications in the title bar according to the settings
in Preference Dialog .
The Title Bar is provided by the operating system, not by
GIMP , so its appearance is likely to vary with
the operating system, window manager, and/or theme — in Linux
systems, this title bar has a button to display the image
window on all your desktops. You also have this button in toolbox window
and layer window.
If you have opened a non-xcf image, it is “ (imported) ”
as a .xcf file and its original name appears in the status bar at the
bottom of the image window .
When an image is modified, an asterisk appears in front of title.
Image Menu:
Directly below the Title Bar appears the Menu bar (unless it has
been suppressed). The Image Menu provides access to nearly every
operation you can perform on an image. You can also right- click
on an image to display a pop-up image menu,
[1] ,
or by left-clicking on the little “ arrow-head ” symbol in
the upper left corner , called Menu Button ,
described just below.
Many menu commands are also associated with keyboard
shortcuts as shown in the menu.
You can define your own custom shortcuts for menu actions, if
you enable Use Dynamic Keyboard
Shortcuts in the Preferences dialog.
Menu Button:
Click the Menu Button to display the Image Menu in a column,(essential
in full screen mode).
If you like to use keyboard shortcuts, use
Shift + F10
to open the menu.
Ruler:
In the default layout, rulers are shown above and to the left of the
image. Use the rulers to determine coordinates within the image.
The default unit for rulers is pixels; use the settings
described below to use a unit other than pixels.
One of the most important uses of rulers is to create
guides .
Click and drag a ruler into the image to create a guide.
A guide is a line that helps you accurately position
things—or verify that another line is truly horizontal
or vertical.
Click and drag a guide to move it. Drag a guide out of the
image to delete it ; you can always drag another guide into the
image. You can even use multiple guides at the same time.
In ruler area, the mouse pointer position is marked with two small
arrow-heads pointing vertically and horizontally.
QuickMask Toggle:
The small button in the lower left corner of the image toggles the
Quick Mask on and off. When the Quick Mask is on, the button is
outlined in red. See QuickMask
for more details on this highly useful tool.
Pointer Coordinates:
When the pointer (mouse cursor, if you are using a mouse) is
within the image boundaries, the rectangular area in the lower
left corner of the window displays the current pointer
coordinates. The units are the same as for the rulers.
Units Menu:
Use the Units Menu to change the units used for rulers and several
other purposes. The default unit is pixels, but you can quickly
change to inches, cm, or several other possibilities using this menu.
Note that the setting of
“ Dot for dot ” in the View menu affects how the display is
scaled: see Dot for Dot
for more information.
Zoom Button:
There are a number of ways to zoom the image in or out, but the Zoom
Button is perhaps the simplest. You can directly enter a zoom level in
the text box for precise control.
Status Area:
The Status Area is at the bottom of the image window .
By default, the Status Area displays the original name of the image.xcf
file, and the amount of system memory used by the image . Please use
Edit → Preferences → Image Windows → Title & Status
to customize the information displayed in the Status Area.
During time-consuming operations, the status area temporarily
shows the running operation and how complete the operation is.
Note
Note that the memory used by the image is very
different from the image file size. For instance, a 70Kb .PNG
image may occupy 246Kb in RAM when displayed.
There are two primary reasons the difference in memory usage.
First, a .PNG file is compressed format, and the image is
reconstituted in RAM in uncompressed form.
Second, GIMP uses extra memory, and copies
of the image, for use by the Undo command.
Cancel Button:
During complex time-consuming operations, usually a plug-in,
a Cancel button temporarily appears in the lower right corner
of the window . Use the Cancel button to stop the operation.
Note
A few plug-ins respond badly to being canceled, sometimes
leaving corrupted pieces of images behind.
Navigation Control:
This is a small cross-shaped button at the lower right corner of the
image display. Click and hold (do not release the mouse button)
on the navigation control to display the Navigation Preview.
The Navigation Preview has a miniature view of the image
with the displayed area outlined. Use the Navigation Preview
to quickly pan to a different part of the
image—move the mouse while keeping the button pressed.
The Navigation Window is often the most convenient way to
quickly navigate around a large image with only a small portion
displayed. (See
Navigation Dialog
for other ways to access the Navigation Window). (If your mouse has a
middle-button, click-drag with it to pan across the image ).
Inactive Padding Area:
When the image dimensions are smaller than the image window , this
padding area separates the active image display and the inactive
padding area, so you're able to distinguish between them. You cannot
apply any Filters or Operations in general to the inactive area.
Image Display:
The most important part of the image window is, of course, the image
display or canvas. It occupies the central area of the window,
surrounded by a yellow dotted line showing the image boundary, against
a neutral gray background. You can change the zoom level of the image
display in a variety of ways , including the Zoom setting described
below.
Image Window Resize Toggle:
Without enabling this feature, if you change the size of the image
window by click-and-dragging border limits, the image size and zoom
does not change. If you make the
window larger, for example, then you will see more of the image.
If this button is pressed, however, the image resizes when the window
resizes so that (mostly) the same portion of the image is displayed
before and after the window is resized.
Tip
Drag and drop an image into the Toolbox window from a file browser to
open the image in its own Image window or tab.
Dragging an image file into the Layer dialog adds it to the image as a
new layer.
Image size and image window size can be different. You can make image fit
window, and vice versa, using two keyboard shortcuts:
Ctrl + J : this
command keeps the zoom level; it adapts window size to image size.
The Shrink Wrap command does the same.
Ctrl + Shift + J : this command modifies the zoom level
to adapt the image display to the window.
[1]
Users with an Apple Macintosh and a one button mouse can use
Ctrl + mousebutton instead.
2. Main Windows 2.3. Dialogs and Docking
 Report an error in Bugzilla  Chapter 5. Getting Images into GIMP Chapter 5. Getting Images into GIMP Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 5. Getting Images into GIMP Table of Contents 1. Image Types 2. Creating new Files 3. Opening Files 3.1. Open File 3.2. Open Location 3. 3. Open Recent 3.4. Using External Programs 3.5. File Manager 3.6. Drag and Drop 3.7. Copy and Paste 3.8. Image Browser
This chapter is about getting images into GIMP. It explains how to
create new images, how to load images from files, how to scan them and
how to make screenshots.
But first we want to introduce you to the general structure of images
in GIMP.
1. Image Types
It is tempting to think of an image as
something that corresponds with a single display window, or to a
single file such as a JPEG
file. In reality, however, a GIMP image is a
a complicated structure,
containing a stack of layers plus several other types of objects:
a selection mask, a set of channels, a set of paths, an "undo"
history, etc. In this section we take a detailed
look at the components of a GIMP image,
and the things that you can do with them.
The most basic property of an image is its
mode . There are three possible modes: RGB,
grayscale, and indexed. RGB stands
for Red-Green-Blue, and indicates that each point in the image
is represented by a “ red ” level, a “ green ”
level, and a “ blue ”
level; representing a full-color image.
Each color channel has 256 possible intensity
levels. More details in
Color Models
In a grayscale image, each point is represented by a brightness
value, ranging from 0 (black) to 255 (white), with intermediate
values representing different levels of gray.
Figure 5.1. Components of the RGB and CMY Color Model
In the RGB Color Model, mixing Red, Green and Blue gives White,
which is what happens on your screen.
In the CMY(K) color model, mixing Cyan, Magenta and Yellow gives
Black, which is what happens when you print on a white paper. The
printer will actually use the black cartridge for economical
reasons and better color rendering.
Conceptually, the difference between a grayscale image and an RGB
image is the number of “ color channels ” : a grayscale image
has one; an RGB image has three. An RGB image can be thought of as
three superimposed grayscale images, one colored red, one green,
and one blue.
Actually, both RGB and grayscale images have one additional
color channel called the alpha channel, which
represents opacity. When the alpha value at a given location
in a given layer is zero, the layer is completely transparent
(you can see through it),
and the color at that location is determined by what lies
underneath. When alpha is maximal (255), the layer is opaque
(you cannot see through it), and the
color is determined by the color of the layer. Intermediate
alpha values correspond to varying degrees of transparency / opacity:
the
color at the location is a proportional mixture of color from the
layer and color from underneath.
Figure 5.2. Example of an image in RGB and Grayscale mode
An image in RGB mode, with the channels corresponding to Red,
Green and Blue.
An image in Grayscale mode, with the channel corresponding to
Luminosity.
In GIMP , every color channel, including the alpha
channel, has a range
of possible values from 0 to 255; in computing terminology, a depth of 8
bits. Some digital cameras can produce image files with a depth of 16
bits per color channel. GIMP cannot load such a file
without losing
resolution. In most cases the effects are too subtle to be detected by
the human eye, but in some cases, mainly where there are large areas
with slowly varying color gradients, the difference may be perceptible.
Figure 5.3. Example of an image with alpha channel Red channel Green channel Blue channel
The Alpha channel shows the image area which is transparent.
A color image in RGB mode with an Alpha channel.
The third type, indexed
images, is a bit more complicated to understand. In an indexed image,
only a limited set of discrete colors are used, usually 256 or less.
These colors form the “ colormap ” of the image, and each
point in the image is assigned a color from the colormap. Indexed images
have the advantage that they can be represented inside a computer in a
way which consumes relatively little memory, and back in the dark ages
(say, ten years ago), they were very commonly used. As time goes on, they
are used less and less, but they are still important enough to be worth
supporting in GIMP . (Also, there are a few important
kinds of image
manipulation that are easier to implement with indexed images than with
continuous-color RGB images.)
Some very commonly used types of files (including
GIF and
PNG ) produce
indexed images when they are opened in GIMP . Many of
GIMP 's
tools don't work very well on indexed images–and many filters
don't work at all–because of the limited number of colors
available. Because of this, it is usually best to convert an
image to RGB mode before working on it. If necessary, you can
convert it back to indexed mode when you are ready to save it
GIMP makes it easy to convert from one image type to
another,
using the Mode command in
the Image menu. Some types of conversions, of course (RGB to
grayscale or indexed, for example) lose information that cannot
be regained by converting back in the other direction.
Note
If you are trying to use a filter on an image, and it appears grayed out
in the menu , usually the cause is that the image (or, more specifically,
the layer) you are working on is the wrong type. Many filters can't be
used on indexed images. Some can be used only on RGB images, or only on
grayscale images. Some also require the presence or absence of an alpha
channel. Usually the fix is to convert the image to a different type,
most commonly RGB.
Part II.
How do I Become a GIMP Wizard?
2. Creating new Files
 Report an error in Bugzilla 
Chapter 6. Getting Images out of GIMP Chapter 6. Getting Images out of GIMP Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 6. Getting Images out of GIMP Table of Contents 1. Files 1.1. Save / Export Images 1.2. File Formats 2. Preparing your Images for the Web 2.1. Images with an Optimal Size/Quality Ratio 2.2. Reducing the File Size Even More 2.3. Saving Images with Transparency 1. Files GIMP is capable of reading and writing a large
variety of graphics file formats. With the exception of
GIMP 's native XCF file type, file handling is done by
Plugins. Thus, it is relatively easy to extend GIMP
to support new file types when the need arises.
1.1. Save / Export Images Note
In former GIMP releases, when you loaded an image in
some format, let us say JPG or PNG, the image kept its format and
was saved in the same format by Save . With
GIMP -2.8, images are loaded, imported, in the XCF
format as a new project. For example, a “ sunflower.png ”
image will be loaded as “ *[sunflower] (imported)-1.0 (indexed
color, 1 layer) ” . The leading asterisk indicates that this file
has been changed. This image will be saved as
“ sunflower.xcf ” by Save . To save this
image in a format other than XCF , you must use
Export .
When you are finished working with an image, you will want to save the
results. (In fact, it is often a good idea to save at intermediate
stages too: GIMP
is a pretty robust program, but we have heard rumors, possibly
apocryphal, that it may have been known on rare and mysterious occasions
to crash.) Most of the file formats that GIMP
can open, can also be used for saving. There is one file format that is
special, though: XCF is GIMP 's native format, and is
useful because it stores everything about an image
(well, almost everything; it does not store “ undo ”
information). Thus, the XCF format is especially suitable for saving
intermediate results, and for saving images to be re-opened later in
GIMP .
XCF files are not readable by most other programs that display images,
so once you have finished, you will probably also want to export the image
in a more widely used format, such as JPEG, PNG, TIFF, etc.
1.2. File Formats
There are several commands for saving images. A list,
and information on how to use them, can be found in the section covering
the File Menu .
GIMP allows you to export the
images you create in a wide variety of formats. It is important to
realize that the only format capable of saving all of
the information in an image, including layers, transparency, etc., is
GIMP's native XCF format . Every other format preserves some image
properties and loses others. It is up to you to understand the
capabilities of the format you choose.
Exporting an image does not modify the image itself, so you do not lose
anything by exporting. See
Export file .
Note
When you close an image (possibly by quitting GIMP), you are warned if
the image is "dirty "; that is, if it has been changed without
subsequently being saved (an asterisk is in front of the image name).
Figure 6.1. Closing warning
Saving an image in any file format will cause the image to be considered
"not dirty", even if the file format does not represent all of the
information from the image.
1.2.1. Export Image as GIF Figure 6.2. The GIF Export dialog Warning
The GIF file format does not support some basic image
properties such as print resolution .
If you care for these properties, use a different file
format like PNG.
GIF Options Interlace
Checking interlace allows an image on a web page to be
progressively displayed as it is downloaded.
Progressive image display is useful with slow connection
speeds, because you can stop an image that is of no
interest; interlace is of less use today with our faster
connection speeds.
GIF comment
GIF comments support only 7-bit ASCII characters.
If you use a character outside the 7-bit ASCII set,
GIMP will export the image without
a comment, and then inform you that the comment was not
saved.
Animated GIF Options Loop forever
When this option is checked , the animation will
play repeatedly until you stop it.
Delay between frames where unspecified
You can set the delay, in milliseconds, between frames
if it has not been set before . In this case, you can
modify every delay in the Layer Dialog.
Frame disposal where unspecified
If this has not been set before , you can set how frames
will be superimposed. You can select among three options :
I don't care :
you can use this option if all your layers are
opaque. Layers will overwrite what is beneath.
Cumulative Layers (combine) :
previous frames will not be deleted when a new one
is displayed.
One frame per layer (replace) :
previous frames will be deleted before displaying a
new frame.
Use delay entered above for all frames
Self-explanatory.
Use disposal entered above for all frames
Self-explanatory.
1.2.2. Export Image as JPEG
JPEG files usually have an extension .jpg, .JPG, or .jpeg. It is a
very widely used format, because it compresses images very
efficiently, while minimizing the loss of image quality. No other
format comes close to achieving the same level of compression. It does
not, however, support transparency or multiple layers.
Figure 6.3. The JPEG Export dialog
The JPEG algorithm is quite complex, and involves a bewildering number
of options, whose meaning is beyond the scope of this documentation .
Unless you are a JPEG expert, the Quality parameter is probably the
only one you will need to adjust.
Quality
When you save a file in JPEG format, a dialog is displayed
that allows you to set the Quality level , which ranges from 0
to 100 . Values above 95 are generally not useful, though. The
default quality of 85 usually produces excellent results, but
in many cases it is possible to set the quality substantially
lower without noticeably degrading the image. You can test the
effect of different quality settings by checking
Show Preview in image window
in the JPEG dialog.
Note
Please note, that the numbers for the JPEG quality level have
a different meaning in different applications.
Saving with a quality level of 80 in GIMP is not
necessarily comparable with saving with a quality level of
80 in a different application.
Preview in image window
Checking this option causes each change in quality (or any other
JPEG parameter) to be shown in the image display. (This does not
alter the image : the image reverts back to its original state
when the JPEG dialog is closed.)
Advanced settings
Some information about the advanced settings:
Optimize
If you enable this option, the optimization of entropy
encoding parameters will be used. The result is typically
a smaller file, but it takes more time to generate.
Progressive
With this option enabled, the image chunks are
stored in the file in an order that allows
progressive image refinement
during a slow connection web download.
The progressive option for JPG has the same
purpose as the interlace option for GIF.
Unfortunately, the progressive option produces
slightly larger JPG files (than without the
progressive option).
Save EXIF data
JPEG files from many digital cameras contain extra
information, called EXIF data.
EXIF data provides information about the image such as
camera make and model, image size, image date, etc.
Although GIMP uses the “ libexif ” library to
read and write EXIF data, the library is not
automatically packaged with GIMP. If GIMP was built with
libexif support, then EXIF data is preserved if you open a
JPEG file, work with the resulting image, and then export
it as JPEG. The EXIF data is not altered in any way when
you do this. The EXIF data may indicate things such as
image creation time and file name, which may no longer be
correct.
If GIMP was not built with EXIF support, you can still
open JPG files containing EXIF data, but the EXIF data
is ignored, and will not be saved when the resulting image
is later exported.
Save thumbnail
This option lets you save a thumbnail with the image.
Many applications use the small thumbnail image as
a quickly available small preview image.
Note
This option is present only if GIMP
was built with EXIF support.
Save XMP data
XMP data is “ meta ” data about the image;
it is a competing format with EXIF.
If you enable this option, the meta data of the image is
saved in an XMP -structure within the
file.
Use quality settings from original image
If a particular quality setting (or “ quantization
table ” ) was attached to the image when it was
loaded, then this option allows you to use them instead of
the standard ones.
If you have only made a few changes to the image, then
re-using the same quality setting will give you almost the
same quality and file size as the original image . This
will minimize the losses caused by the quantization step,
compared to what would happen if you used different
quality setting.
If the quality setting found in the original file are not
better than your default quality settings, then the option
“ Use quality settings from original image ”
will be available but not enabled. This ensures that you
always get at least the minimum quality specified in your
defaults. If you did not make major changes to the image
and you want to save it using the same quality as the
original, then you can do it by enabling this option.
Smoothing
JPG compression creates artifacts. By using this option,
you can smooth the image when saving, reducing them. But
your image becomes somewhat blurred.
Restart markers
The image file can include markers which allow the image
to be loaded as segments. If a connection is broken while
loading the image in a web page,
loading can resume from the next marker.
Subsampling
The human eye is not sensitive in the same way over
the entire color spectrum. The compression
can use this to treat slightly different colors
that the eye perceives as very close, as identical
colors. Three methods are available :
1x1,1x1,1x1 (best quality) :
Commonly referred to as (4: 4:4), this produces
the best quality,
preserving borders and contrasting colors, but
compression is less.
2x1,1x1,1x1 (4:2:2) :
This is the standard subsampling, which usually
provides a good ratio between image quality and file
size. There are situations, however, in which using no
subsampling (4:4:4) provides a noticeable increase in
the image quality; for example, when the image
contains fine details such as text over a uniform
background, or images with almost-flat colors.
1x2,1x1,1x1
This is similar to
(2x1,1x1,1x1), but the chroma sampling is in the
horizontal direction rather than the vertical
direction; as if someone rotated an image.
2x2,1x1,1x1 (smallest file) :
Commonly referred to as (4: 1:1), this produces
the smallest files. This suits images with weak
borders but tends to denature colors.
DCT Method
DCT is “ discrete cosine transform ” ,
and it is the first step in the JPEG algorithm going
from the spatial to the frequency domain. The choices are
“ float ” , “ integer ”
(the default), and “ fast integer ” .
float :
The float method is very slightly more accurate than
the integer method, but is much slower unless your
machine has very fast floating-point hardware. Also
note that the results of the floating-point method may
vary slightly across machines, while the integer
methods should give the same results everywhere.
integer
(the default): This method is faster than
“ float ” , but not as accurate.
fast integer :
The fast integer method is much less accurate than
the other two.
Image comments
In this text box, you can enter a comment which is
saved with the image .
1.2. 3. Export Image as PNG Figure 6.4. The “ Export Image as PNG ” dialog Interlacing
Checking interlace allows an image on a web page to be
progressively displayed as it is downloaded.
Progressive image display is useful with slow connection
speeds, because you can stop an image that is of no
interest; interlace is of less use today with our faster
connection speeds.
Save background color
If your image has many transparency levels, the Internet
browsers that recognize only two levels, will use the
background color of your Toolbox instead. Internet Explorer
up to version 6 did not use this information.
Save gamma
Gamma correction is the ability to correct for
differences in how computers interpret color values.
This saves gamma information in the PNG that reflects
the current Gamma factor for your display. Viewers on
other computers can then compensate to ensure that the image
is not too dark or too bright.
Save layer offset
PNG supports an offset value called the
“ oFFs chunk ” , which provides position data.
Unfortunately, PNG offset support in GIMP
is broken, or at least is not compatible with other
applications,
and has been for a long time. Do not enable offsets,
let GIMP flatten the layers before
saving, and you will have no problems.
Save Resolution Save the image resolution, in ppi (pixels per inch). Save creation time
Date the file was saved.
Save comment
You can read this comment in the
Image Properties .
Save color values from transparent pixels
With this option is checked, the color values are saved even if
the pixels are completely transparent.
Compression level
Since compression is not lossy, the only reason to use a
compression level less than 9, is if it takes too long to
compress a file on a slow computer.
Nothing to fear from
decompression: it is as quick whatever the compression level.
Save Defaults
Click to save the current settings . Latter, you can use
Load Defaults to load the saved
settings.
Note
The PNG format supports indexed images. Using fewer colors,
therefore, results in a smaller file; this is especially useful
for creating web images;
see Section 6.6, “Indexed mode” .
Computers work on 8 bits blocks named “ Byte ” .
A byte allows 256 colors. Reducing the number of colors below 256
is not useful: a byte will be used anyway and the file size will not
be less. More, this “ PNG8 ”
format, like GIF, uses only one bit for transparency; only two
transparency levels are possible, transparent or opaque.
If you want PNG transparency to be fully displayed by Internet
Explorer, you can use the AlphaImageLoader DirectX filter in the
code of your Web page. See Microsoft Knowledge Base
[ MSKB-294714 ] .
Please note, that this is not necessary for
InternetExplorer 7 and above.
1.2.4. Export Image as TIFF Figure 6.5. The TIFF Export dialog Compression
This option allows you to specify the algorithm used to
compress the image.
None : is fast, and lossless, but the
resulting file is very large.
LZW : The image is compressed
using the “ Lempel-Ziv-Welch ” algorithm, a
lossless compression technique. This is old, but
efficient and fast. More information at
[ WKPD-LZW ] .
Pack Bits : is a fast, simple
compression scheme for run-length encoding of data. Apple
introduced the PackBits format with the release of
MacPaint on the Macintosh computer. A PackBits data
stream consists of packets of one byte of header followed
by data. (Source:
[ WKPD-PACKBITS ] )
Deflate : is a lossless data
compression algorithm that uses a combination of the LZ77
algorithm and Huffman coding. It is also used in Zip,
Gzip and PNG file formats. Source:
[ WKPD-DEFLATE ] .
JPEG : is a very good
compression algorithm but lossy.
CCITT Group 3 fax ;
CCITT Group 4 fax is a
black and white format developed to transfer images by FAX.
Note
These options can only be selected, if the image is in
indexed mode and reduced to two colors. Use
Image → Mode → Indexed to convert the image to indexed . Be certain to check
“ Use black and white (1-bit) palette ” .
Save color values from transparent pixels
With this option the color values are saved even if the pixels
are completely transparent.
Comment
In this text box, you can enter a comment that is
associated with the image.
1.2. 5. Export Image as MNG Figure 6.6. Export MNG File Dialog
MNG is acronym for “ Multiple-Image Network Graphics ” .
The main problem is that Konqueror is the only Web navigator that
recognizes the MNG animation format. Please see
http://en.wikipedia.org/wiki/Multiple-image_Network_Graphics .
3.8. Image Browser 2. Preparing your Images for the Web  Report an error in Bugzilla  Chapter 11. Color Management with GIMP Chapter 11. Color Management with GIMP Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 11. Color Management with GIMP Table of Contents 1. Color Management in GIMP 1.1. Problems of a non Color Managed Workflow 1.2. Introduction to a Color Managed Workflow 1. Color Management in GIMP
Many devices you use in your design or photography workflow, like digital
photo cameras, scanners, displays, printers etc., have their own color
reproduction characteristics. If those are not taken into account during
opening, editing and saving, harmful adjustments can be done to images.
With GIMP you can have reliable output for both Web
and print.
Figure 11.1. Image Processing Workflow Workflow without Color management Process with Color management 1.1. Problems of a non Color Managed Workflow
The basic problem of image manipulation without color management is that
you do simply not see what you do. This affects two different areas:
There are differences in Colors caused by different color
characteristics of different devices like cameras, scanners,
displays or printers
There are differences in Colors caused by the limitations of the
colorspace a specific device is able to handle
The main purpose of color management is to avoid such problems. The
approach taken to do so involves the addition of a description of the
color characteristic to an image or devices.
These descriptions are called color profile . A
color profile is basically a look-up table to translate the specific
color characteristic of a device to a device-independent color space -
the so called working-space. All the image manipulation is then done to
images in the working-space. In addition to that the color profile of a
device can be used to simulate how colors would look on that device.
The creation of color profiles is most often done by the manufacturer
of the devices themselves. To make these profiles usable independent of
platform and operating system, the ICC (International Color Consortium)
created a standard called ICC-profile that describes how color profiles
are stored to files and embedded into images.
1.2. Introduction to a Color Managed Workflow Tip
Most of the parameters and profiles described here can be set in the
GIMP preferences. Please see
Section 1.14, “Color Management” for details.
1.2.1. Input
Most digital cameras embed a color profile to individual photo files
without user interaction. Digital scanners usually come with a color
profile, which they also attach to the scanned images.
Figure 11.2. Applying the ICC-profile
When opening an image with an embedded color profile,
GIMP offers to
convert the file to the RGB working color space. This is sRGB by
default and it is recommended that all work is done in that color
space. Should you however decide to keep the embedded color profile,
the image will however still be displayed correctly.
In case for some reason a color profile is not embedded in the image
and you know (or have a good guess) which one it should be, you can
manually assign it to that image.
1.2.2. Display
For the best results, you need a color profile for your monitor . If a
monitor profile is configured, either system-wide or in the Color
Management section of the GIMP Preferences dialog,
the image colors will be displayed most accurately.
One of the most important GIMP commands to work
with color management is described in
Section 5 .8, “Display Filters” .
If you do not have a color profile for your monitor , you can
create it using hardware calibration and measurement tools. On
UNIX systems you will need
Argyll Color Management System ™
[ ARGYLLCMS ] and/or
LProf ™
[ LPROF ]
to create color profiles.
1.2.2.1. Display Calibration and Profiling
For displays there are two steps involved. One is called calibration
and the other is called profiling. Also, calibration generally
involves two steps. The first involves adjusting external monitor
controls such as Contrast, Brightness, Color Temperature, etc, and
it is highly dependent on the specific monitor. In addition there
are further adjustments that are loaded into the video card memory
to bring the monitor as close to a standard state as possible. This
information is stored in the monitor profile in the so-called vgct
tag. Probably under Windows XP or Mac OS, the operating system loads
this information (LUT) in the video card in the process of starting
your computer. Under Linux, at present you have to use an external
program such as xcalib or dispwin. (If one just does a simple visual
calibration using a web site such as that of Norman Koren, one might
only use xgamma to load a gamma value.)
The second step, profiling, derives a set of rules which allow
GIMP
to translate RGB values in the image file into appropriate colors on
the screen. This is also stored in the monitor profile . It doesn't
change the RGB values in the image , but it does change which values
are sent to the video card (which already contains the vgct LUT).
1.2.3. Print Simulation
Using GIMP , you can easily get a preview of what
your image will look
like on paper. Given a color profile for your printer, the display can
be switched into Soft Proof mode. In such a simulated printout, colors
that cannot be reproduced will optionally be marked with neutral gray
color, allowing you to correct such mistakes before sending your
images to the printer.
Chapter 10. Enhancing Photographs Chapter 12. Enrich my GIMP  Report an error in Bugzilla 
Chapter 10. Enhancing Photographs Chapter 10. Enhancing Photographs Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 10. Enhancing Photographs Table of Contents 1. Working with Digital Camera Photos 1.1. Introduction 1.2. Improving Composition 1.3. Improving Colors 1.4. Adjusting Sharpness 1.5. Removing Unwanted Objects from an Image 1.6. Saving Your Results 1. Working with Digital Camera Photos 1.1. Introduction One of the most common uses of GIMP is to fix digital camera images
that for some reason are less than perfect. Maybe the image is
overexposed or underexposed; maybe rotated a bit; maybe out of focus:
these are all common problems for which GIMP has good tools. The purpose
of this chapter is to give you an overview of those tools and the
situations in which they are useful. You will not find detailed
tutorials here: in most cases it is easier to learn how to use the tools
by experimenting with them than by reading about them. (Also, each tool
is described more thoroughly in the Help section devoted to it.) You
will also not find anything in this chapter about the multitude of
"special effects" that you can apply to an image using GIMP. You should
be familiar with basic GIMP concepts before reading this chapter, but
you certainly don't need to be an expert–if you are, you probably know
most of this anyway. And don't hesitate to experiment: GIMP's powerful
"undo" system allows you to recover from almost any mistake with a
simple Ctrl + Z .
Most commonly the things that you want to do to clean up an imperfect
photo are of four types: improving the composition; improving the
colors; improving the sharpness; and removing artifacts or other
undesirable elements of the image.
1.2. Improving Composition 1.2.1. Rotating an Image
It is easy, when taking a picture, to hold the camera not quite
perfectly vertical, resulting in a picture where things are
tilted at an angle. In GIMP, the way to fix this is to use the
Rotate tool.
Activate this by clicking its icon
in the Toolbox, or by pressing the
Shift + R while
inside the image. Make sure the Tool Options are visible , and at
the top, make sure for “ Transform: ” that the left
button ( “ Transform Layer ” ) is selected. If you then
click the mouse inside the image and drag it, you will see a grid
appear that rotates as you drag. When the grid looks right, click
Rotate or press Enter , and
the image will be rotated .
Now as a matter of fact, it isn't so easy to get things right by this
method: you often find that things are better but not quite perfect.
One solution is to rotate a bit more, but there is a disadvantage to
that approach. Each time you rotate an image, because the rotated
pixels don't line up precisely with the original pixels, the image
inevitably gets blurred a little bit. For a single rotation, the
amount of blurring is quite small, but two rotations cause twice as
much blurring as one, and there is no reason to blur things more than
you have to. A better alternative is to undo the rotation and then do
another, adjusting the angle.
Fortunately, GIMP provides another way of doing it that is
considerably easier to use: in the Rotate Tool Options, for the
Transform Direction you can select "Backward (Corrective)". When you
do this, instead of rotating the grid to compensate for the error, you
can rotate it to line up
with the error. If this seems confusing, try it and you will see that
it is quite straightforward.
Note
Since GIMP 2.2, there is an option to preview the results of
transformations, instead of just seeing a grid. This makes it easier
to get things right on the first try.
After you have rotated an image, there will be unpleasant triangular
"holes" at the corners. One way to fix them is to create a background
that fills the holes with some unobtrusive or neutral color, but
usually a better solution is to crop the image. The greater the
rotation, the more cropping is required, so it is best to get the
camera aligned as well as possible when you take the picture in the
first place.
1.2.2. Cropping
When you take a picture with a digital camera, you have some control
over what gets included in the image but often not as much as you
would like: the result is images that could benefit from trimming.
Beyond this, it is often possible to enhance the impact of an image by
trimming it so that the most important elements are placed at key
points. A rule of thumb, not always to be followed but good to keep in
mind, is the “ rule of thirds ” ,
which says that maximum impact is obtained by placing the center of
interest one-third of the way across the image, both widthwise and
heightwise.
To crop an image, activate the
Crop
tool in the Toolbox, or by pressing the “ C ”
key (capitalized) while inside the image. With the tool active,
clicking and dragging in the image will sweep out a crop rectangle. It
will also pop up a dialog that allows you to adjust the dimensions of
the crop region if they aren't quite right. When everything is
perfect, hit the Crop button in the dialog.
1.3. Improving Colors 1.3.1. Automated Tools
In spite of sophisticated exposure-control systems, pictures taken
with digital cameras often come out over- or under-exposed, or with
color casts due to imperfections in lighting. GIMP gives you a variety
of tools to correct colors in an image, ranging to automated tools
that run with a simple button-click to highly sophisticated tools that
give you many parameters of control. We will start with the simplest
first.
GIMP gives you several automated color correction
tools. Unfortunately they don't usually give you quite the results
you are looking for, but they only take a moment to try out, and if
nothing else they often give you an idea of some of the
possibilities inherent in the image. Except for "Auto Levels", you
can find these tools by following the menu path
Colors → Auto
in the image menu.
Here they are, with a few words about each: Normalize
This tool (it is really a plug-in) is useful for underexposed
images: it adjusts the whole image uniformly until the brightest
point is right at the saturation limit, and the darkest point is
black. The downside is that the amount of brightening is
determined entirely by the lightest and darkest points in the
image, so even one single white pixel and/or one single black
pixel will make normalization ineffective.
Equalize
This is a very powerful adjustment that tries to spread the
colors in the image evenly across the range of possible
intensities. In some cases the effect is amazing, bringing out
contrasts that are very difficult to get in any other way; but
more commonly, it just makes the image look weird. Oh well, it
only takes a moment to try.
Color Enhance
This command increases the saturation range of the colors in the
layer, without altering brightness or hue. So this command does
not work on grayscale images.
Stretch Contrast
This is like “ Normalize ” ,
except that it operates on the red, green, and blue channels
independently. It often has the useful effect of reducing color
casts.
Stretch HSV
Does the same as Stretch Contrast but works in HSV color
space, rather than RGB color space . It preserves the Hue.
White balance
This may enhance images with poor white or black by
removing little used colors and stretch the remaining
range as much as possible.
Auto Levels
This is done by activating the Levels tool
( Tools → Color Tools → Levels
or
Colors → Levels
in the image menu ),
and then pressing the Auto button near
the center of the dialog . You will see a preview of the result;
you must press Okay for it to take
effect. Pressing Cancel instead will
cause your image to revert to its previous state.
If you can find a point in the image that ought to be perfect
white, and a second point that ought to be perfect black, then
you can use the Levels tool to do a semi-automatic adjustment
that will often do a good job of fixing both brightness and
colors throughout the image. First, bring up the Levels tool as
previously described. Now, look down near the bottom of the
Layers dialog for three buttons with symbols on them that look
like eye-droppers (at least, that is what they are supposed to
look like). The one on the left, if you mouse over it, shows its
function to be “ Pick Black Point ” .
Click on this, then click on a point in the image that ought
to be black–really truly perfectly black, not just sort of
dark–and watch the image change. Next, click on the rightmost of
the three buttons ( “ Pick White Point ”
), and then click a point in the image that ought to be white,
and once more watch the image change. If you are happy with the
result, click the Okay button otherwise
Cancel .
Those are the automated color adjustments: if you find that none of
them quite does the job for you, it is time to try one of the
interactive color tools. All of these, except one, can be accessed via
Tools- & gt;Color Tools in the image menu. After you select a color tool,
click on the image (anywhere) to activate it and bring up its dialog.
1.3.2. Exposure Problems
The simplest tool to use is the Brightness/Contrast
tool. It is also the least powerful, but in many cases it does
everything you need. This tool is often useful for images that are
overexposed or underexposed; it is not useful for correcting color
casts. The tool gives you two sliders to adjust, for
“ Brightness ” and “ Contrast ” . If you have
the option “ Preview ” checked (and almost certainly you
should),you will see any adjustments you make reflected in the
image. When you are happy with the results, press
Okay and they will take effect. If you
can't get results that you are happy with, press
Cancel and the image will revert to its
previous state.
A more sophisticated, and only slightly more difficult, way of
correcting exposure problems is to use the Levels tool . The
dialog for this tool looks very complicated, but for the basic
usage we have in mind here, the only part you need to deal
with is the “ Input Levels ” area, specifically the three
triangular sliders that appear below the histogram. We refer
you to the Levels Tool Help
for instructions;
but actually the easiest way to learn how to use it is to
experiment by moving the three sliders around, and watching
how the image is affected. (Make sure that “ Preview ” is
checked at the bottom of the dialog .)
A very powerful way of correcting exposure problems is to use the
Curves
tool. This tool allows you to click and drag control points on a
curve, in order to create a function mapping input brightness levels
to output brightness levels. The Curves tool can replicate any effect
you can achieve with Brightness/Contrast or the Levels tool, so it is
more powerful than either of them. Once again, we refer you to the
Curves Tool Help
for detailed instructions, but the easiest way to learn how to use it
is by experimenting.
The most powerful approach to adjusting brightness and contrast across
an image, for more expert GIMP users, is to create a new layer above
the one you are working on, and then in the Layers dialog set the Mode
for the upper layer to “ Multiply ” .
The new layer then serves as a “ gain control ”
layer for the layer below it, with white yielding maximum gain and
black yielding a gain of zero. Thus, by painting on the new layer, you
can selectively adjust the gain for each area of the image, giving you
very fine control. You should try to paint only with smooth gradients,
because sudden changes in gain will give rise to spurious edges in the
result. Paint only using shades of gray, not colors, unless you want
to produce color shifts in the image .
Actually, “ Multiply ” is not the only mode that is useful
for gain control. In fact, “ Multiply ” mode can only
darken parts of an image, never lighten them, so it is only useful
where some parts of an image are overexposed. Using
“ Divide ” mode has the opposite effect: it can brighten
areas of an image but not darken them. Here is a trick that is often
useful for bringing out the maximum amount of detail across all areas
of an image:
Duplicate the layer (producing a new layer above it).
Desaturate the new layer.
Apply a Gaussian blur to the result, with a large radius (100 or
more).
Set Mode in the Layers dialog to Divide.
Control the amount of correction by adjusting opacity in the
Layers dialog , or by using Brightness/Contrast, Levels, or Curves
tools on the new layer.
When you are happy with the result, you can use
Merge Down
to combine the control layer and the original layer into a single
layer.
In addition to “ Multiply ” and “ Divide ” , you
may every so often get useful effects with other layer combination
modes, such as “ Dodge ” , “ Burn ” , or
“ Soft Light ” . It is all too easy, though,
once you start playing with these things, to look away from
the computer for a moment and suddenly find that you have just
spent an hour twiddling parameters. Be warned: the more
options you have, the harder it is to make a decision.
1.3.3. Adjusting Hue and Saturation
In our experience, if your image has a color cast---too much red, too
much blue, etc---the easiest way to correct it is to use the Levels
tool , adjusting levels individually on the red, green, and blue
channels . If this doesn't work for you, it might be worth your while
to try the Color Balance tool or the Curves tool, but these are much
more difficult to use effectively. (They are very good for creating
certain types of special effects, though.)
Sometimes it is hard to tell whether you have adjusted colors
adequately. A good, objective technique is to find a point in the
image that you know should be either white or a shade of gray.
Activate the
Color Picker
tool (the eyedropper symbol in the Toolbox), and click on the
aforesaid point: this brings up the Color Picker dialog. If the colors
are correctly adjusted, then the red, green, and blue components of
the reported color should all be equal; if not, then you should see
what sort of adjustment you need to make. This technique, when well
used, allows even color-blind people to color-correct an image.
If your image is washed out---which can easily happen when you take
pictures in bright light---try the
Hue/Saturation
tool, which gives you three sliders to manipulate, for Hue, Lightness,
and Saturation. Raising the saturation will probably make the image
look better. In same cases it is useful to adjust the lightness at the
same time. ( “ Lightness ” here is similar to
“ Brightness ”
in the Brightness/Contrast tool, except that they are formed from
different combinations of the red, green, and blue channels .) The
Hue/Saturation tool gives you the option of adjusting restricted
subranges of colors ( using the buttons at the top of the dialog ), but
if you want to get natural-looking colors, in most cases you should
avoid doing this.
Tip
Even if an image does not seemed washed out, often you can increase
its impact by pushing up the saturation a bit. Veterans of the film
era sometimes call this trick “ Fujifying ” ,
after Fujichrome film, which is notorious for producing highly
saturated prints.
When you take pictures in low light conditions , in some cases you have
the opposite problem: too much saturation. In this case too the
Hue/Saturation tool is a good one to use, only by reducing the
saturation instead of increasing it.
1.4. Adjusting Sharpness 1.4.1. Unblurring
If the focus on the camera is not set perfectly, or the camera is
moving when the picture is taken, the result is a blurred image. If
there is a lot of blurring, you probably won't be able to do much
about it with any technique, but if there is only a moderate amount,
you should be able to improve the image.
The most generally useful technique for sharpening a fuzzy image is
called the Unsharp Mask .
In spite of the rather confusing name, which derives from its
origins as a technique used by film developers, its result is to make
the image sharper, not “ unsharp ” .
It is a plug-in, and you can access it as Filters- & gt; Enhance- & gt; Unsharp
Mask in the image menu. There are two parameters,
“ Radius ” and “ Amount ” .
The default values often work pretty well, so you should try them
first. Increasing either the radius or the amount increases the
strength of the effect. Don't get carried away, though: if you make
the unsharp mask too strong, it will amplify noise in the image and
also give rise to visible artifacts where there are sharp edges.
Tip
Sometimes using Unsharp Mask can cause color distortion where there
are strong contrasts in an image. When this happens, you can often
get better results by decomposing the image into separate
Hue-Saturation-Value (HSV) layers, and running Unsharp Mask on the
Value layer only, then recomposing. This works because the human eye
has much finer resolution for brightness than for color. See the
sections on
Decompose and
Compose for more information.
Next to "Unsharp Mask" in the Filters menu is another filter called
Sharpen ,
which does similar things. It is a little easier to use but not
nearly as effective: our recommendation is that you ignore it and go
straight to Unsharp Mask.
In some situations, you may be able to get useful results by
selectively sharpening specific parts of an image using the
Blur or Sharpen
tool from the Toolbox, in "Sharpen" mode. This allows you to increase
the sharpness in areas by painting over them with any paintbrush. You
should be restrained about this, though, or the results will not look
very natural: sharpening increases the apparent sharpness of edges in
the image, but also amplifies noise.
1.4.2. Reducing Graininess
When you take pictures in low-light conditions or with a very fast
exposure time, the camera does not get enough data to make good
estimates of the true color at each pixel, and consequently the
resulting image looks grainy. You can “ smooth out ”
the graininess by blurring the image, but then you will also lose
sharpness. There are a couple of approaches that may give better
results. Probably the best, if the graininess is not too bad, is to
use the filter called
Selective Blur ,
setting the blurring radius to 1 or 2 pixels. The other approach is
to use the Despeckle
filter. This has a nice preview, so you can play with the settings and
try to find some that give good results. When graininess is really
bad, though, it is often very difficult to fix by anything except
heroic measures (i.e., retouching with paint tools).
1.4.3. Softening
Every so often you have the opposite problem: an image is
too
crisp. The solution is to blur it a bit: fortunately blurring an image
is much easier than sharpening it. Since you probably don't want to
blur it very much, the simplest method is to use the
“ Blur ”
plug-in, accessed via Filters- & gt;Blur- & gt;Blur from the image menu. This
will soften the focus of the image a little bit . If you want more
softening, just repeat until you get the result you desire.
1.5. Removing Unwanted Objects from an Image
There are two kinds of objects you might want to remove from an image:
first, artifacts caused by junk such as dust or hair on the lens;
second, things that were really present but impair the quality of the
image, such as a telephone wire running across the edge of a beautiful
mountain landscape.
1.5.1. Despeckling
A good tool for removing dust and other types of lens grunge is the
Despeckle
filter, accessed as Filters- & gt;Enhance- & gt; Despeckle from the image menu.
Very important: to use this filter effectively, you must begin by
making a small selection containing the artifact and a small area
around it. The selection must be small enough so that the artifact
pixels are statistically distinguishable from the other pixels inside
the selection. If you try to run despeckle on the whole image, you
will hardly ever get anything useful. Once you have created a
reasonable selection, activate Despeckle, and watch the preview as you
adjust the parameters. If you are lucky, you will be able to find a
setting that removes the junk while minimally affecting the area
around it. The more the junk stands out from the area around it, the
better your results are likely to be. If it isn't working for you, it
might be worthwhile to cancel the filter, create a different
selection, and then try again.
If you have more than one artifact in the image, it is necessary to
use Despeckle on each individually.
1.5.2. Garbage Removal
The most useful method for removing unwanted “ clutter ”
from an image is the Clone
tool, which allows you to paint over one part of an image using pixel
data taken from another part (or even from a different image). The
trick to using the clone tool effectively is to be able to find a
different part of the image that can be used to
“ copy over ”
the unwanted part: if the area surrounding the unwanted object is very
different from the rest of the image, you won't have much luck. For
example, if you have a lovely beach scene, with a nasty human walking
across the beach who you would like to teleport away, you will
probably be able to find an empty part of the beach that looks similar
to the part he is walking across, and use it to clone over him. It is
quite astonishing how natural the results can look when this technique
works well.
Consult the
Clone Tool Help
for more detailed instructions. Cloning is as much an art as a
science, and the more you practice at it, the better you will get. At
first it may seem impossible to produce anything except ugly blotches,
but persistence will pay off.
Another tool looking very much as the clone tool, but smarter, is the
healing tool which also takes
the area around the destination into account when cloning. A typical
usage is removal of wrinkles and other minor errors in images.
In some cases you may be able to get good results by simply cutting
out the offending object from the image, and then using a plug-in
called “ Resynthesizer ”
to fill in the void. This plug-in is not included with the main GIMP
distribution, but it can be obtained from the author's web site
[ PLUGIN-RESYNTH ] .
As with many things, your mileage may vary.
1.5.3. Removing Red-eye
When you take a flash picture of somebody who is looking directly
toward the camera, the iris of the eye can bounce the light of the
flash back toward the camera in such a way as to make the eye appear
bright red: this effect is called “ red eye ” ,
and looks very bizarre. Many modern cameras have special flash modes
that minimize red-eye, but they only work if you use them, and even
then they don't always work perfectly. Interestingly, the same effect
occurs with animals, but the eyes may show up as other colors, such as
green.
From version 2.4, GIMP incorporated a special remove red eye filter.
Make a selection with one of the selection tools of the red part of
the eye and then choose the “ Remove Red Eye ” filter.
Perhaps you have to fiddle around a bit with the threshold slider to
get the right color.
1.6. Saving Your Results 1. 6.1. Files
What file format should you use to save the results of your work , and
should you resize it? The answers depend on what you intend to use the
image for.
If you intend to open the image in GIMP again for further work,
you should save it in GIMP's native XCF format (i. e., name it
something.xcf), because this is the only format that guarantees
that none of the information in the image is lost.
If you intend to print the image on paper, you should avoid
shrinking the image, except by cropping it. The reason is that
printers are capable of achieving much higher resolutions than
video monitors — 600 to 1400 dpi ( “ dots per
inch ” , the physical density) for typical printers, as
compared to 72 to 100 pixels per inch for monitors. A
3000 x 5000-pixel image looks huge on a monitor, but it
only comes to about 5 inches by 8 inches on paper at 600 ppi.
There is usually no good reason to expand the
image either: you can't increase the true resolution that way, and
it can always be scaled up at the time it is printed. As for the
file format, it will usually be fine to use JPEG at a quality
level of 75 to 85. In rare cases, where there are large swaths of
nearly uniform color, you may need to set the quality level even
higher or use a lossless format such as TIFF instead.
If you intend to display the image on screen or project it with a
video projector, bear in mind that the highest screen resolution
for most commonly available systems is 1600 x 1200, so there is
nothing to gain by keeping the image larger than that. For this
purpose, the JPEG format is almost always a good choice.
If you want to put the image on a web page or send it by email, it
is a good idea to make every effort to keep the file size as small
as possible. First, scale the image down to the smallest size that
makes it possible to see the relevant details (bear in mind that
other people may be using different sized monitors and/or
different monitor resolution settings). Second, save the image as
a JPEG file. In the JPEG save dialog, check the option to
“ Preview in image window ”
, and then adjust the Quality slider to the lowest level that
gives you acceptable image quality. (You will see in the image the
effects of each change.) Make sure that the image is zoomed at 1:1
while you do this, so you are not misled by the effects of
zooming.
See the File Formats
section for more information.
1. 6.2. Printing Your Photos
As in most softwares, in GIMP, printing needs to go to main menu
File → Print .
However it is very useful to keep in mind some elementary concepts
to prevent some unpleasant surprises when looking at result, or to
cure them if that occurs. You always must remember:
that image displayed on the screen is in RGB mode and printing
will be in CMYK mode; consequently color feature you'll get on
printed sheet will not be exactly what you was waiting for. That
depends on the used corresponding chart. For the curious ones some
adding explanations can be got through a click on these useful
Wikipedia links:
ICC-Profile [ WKPD-ICC ]
CMYK [ WKPD-CMYK ]
Gamut [ WKPD-GAMUT ]
that a screen resolution is roughly within a range from 75 up to
100 dpi; a printer resolution is about 10x higher (or more) than a
screen one; printed image size depends on available pixels and
resolution; so actual printed size doesn't correspond inevitably
to what is displayed on screen nor available sheet size.
Consequently, before any printing it is relevant to go to:
Image → Print size
and choose here your convenient output size in
“ print size ” box adjusting either sizes or resolution.
The
symbol shows that the both values are linked. You can dissociate x
and y resolution by clicking on that symbol, but it is risky! Probably
this possibility is open because printers are built with different x
vs. y resolutions. Nevertheless if you unlinked them you can be very
surprised! You can try this in special effects.
Last recommendation: think of checking your margins as well as
centering. It would be a pity if a too much large margin cuts off some
part of your image or if an inappropriate centering damages your work
especially if you use a special photo paper.
1.6.3. EXIF Data
Modern digital cameras, when you take a picture , add information to
the data file about the camera settings and the circumstances under
which the picture was taken. This data is included in JPEG or TIFF
files in a structured format called EXIF. For JPEG files, GIMP is
capable of maintaining EXIF data, if it is built appropriately: it
depends on a library called “ libexif ” ,
which may not be available on all systems. If GIMP is built with
EXIF support enabled, then loading a JPEG file with EXIF data, and
resaving the resulting image in JPEG format, will cause the EXIF data
to be preserved unchanged. This is not, strictly speaking, the right
way for an image editor to handle EXIF data, but it is better than
simply removing it, which is what earlier versions of GIMP did.
If you would like to see the contents of the EXIF data, you can
download from the registry an Exif Browser plug-in
[ PLUGIN-EXIF ] .
If you are able to build and install it on your system, you can
access it as Filters- & gt; Generic- & gt;Exif Browser from the image menu. (See
Installing New Plug-ins
for help.)
3.3. Font Problems Chapter 11. Color Management with GIMP  Report an error in Bugzilla  2. 4. Colormap Dialog 2.4. Colormap Dialog 2. Image Structure Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 4. Colormap Dialog Figure 15.14. An indexed image with 6 colors and its Colormap dialog
The Colormap (Indexed Palette is a better name) dialog allows you to edit
the colormap of an indexed image . (If the mode of the active image is RGB
or Grayscale instead of Indexed, the dialog is empty and unusable.) This
is a dockable dialog; see the section on
Dialogs and Docking
for help on manipulating it.
 2. 4. 1. Activating the dialog
The “ Colormap ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking” for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Colormap ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Colormap . 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Colormap ” dialog from the image-menu:
Windows → Colormap .
2.4.2. Colormaps and Indexed Images
In an Indexed image, instead of being assigned a color directly (as
happens in RGB and Grayscale images), colors are assigned to pixels by
an indirect method, using a look-up table called a
colormap .
To determine the color that should be shown for that pixel, GIMP looks
up the index in the image's colormap. Each indexed image has its own
private colormap. In GIMP, the maximum number of entries in a colormap
is 256. For a maximum-sized colormap, each index from 0 to 255 is
assigned an arbitrary RGB color. There are no rules restricting the
colors that can be assigned to an index or the order they appear in: any
index can be assigned any color.
It is important to realize that the colors in the colormap are the
only colors available for an indexed image (that
is, unless you add new colors to the colormap ). This has a major effect
on many GIMP operations: for example, in a pattern fill, GIMP will
usually not be able to find exactly the right colors in the colormap, so
it will approximate them by using the nearest color available. This is
sometimes referred to as
Quantization .
If the colormap is too limited or poorly chosen, this can easily produce
very poor image quality.
The Colormap dialog allows you to alter the colormap for an image,
either by creating new entries, or by changing the colors for the
existing entries. If you change the color associated with a given index,
you will see the changes reflected throughout the image, as a color
shift for all pixels that are assigned that index. The entries are
numbered with 0 in the upper left corner , 1 to its right, etc.
2.4.3. Using the Colormap dialog
Here are the operations you can perform using this dialog:
Click on a color entry
This sets GIMP's foreground color to the color you click on , as
shown in the Toolbox color area. As a result, this color will be
used for the next painting operation you do.
Ctrl - click on a color entry
This sets GIMP 's background color to the
color you Ctrl - click on,
as shown in the Toolbox color area.
Double- click on a color entry
This sets GIMP's foreground color to the color you click on , and
also brings up a Color Editor that allows you to change that
colormap entry to a new color.
Color index
You can select a different colormap entry by typing its index
here, or clicking the spinbutton to the right.
HTML-Notation
This area shows a hex-code representation (such as is used in
HTML) for the color assigned to the currently selected colormap
entry. You can edit the color here, instead of using a Color
Editor, if you want to. See
HTML notation
Edit color
This button ( in the lower left corner of the dialog) brings up a
Color Editor that allows you to change the color for the currently
selected colormap entry. The effect is similar to double-clicking
on the entry, except that it does not set GIMP's foreground color.
Add color
This button ( in the lower right corner of the dialog) allows you
to add new colors to the colormap . If you click on the button , the
current foreground color, as shown in the Toolbox , will be tacked
on to the end of the colormap. If instead you hold down
Ctrl and click, the background color from the
Toolbox will be added. (If the colormap contains 256 entries, it
is full, and trying to add more will have no effect.)
Tip
If you make a mistake, you can undo it by focusing the pointer in
the image whose colormap you have changed, and then pressing
Ctrl + Z or
choosing
Edit → Undo
in the image menu.
Note
This dialog provides the most commonly used methods for altering the
colormap for an indexed image. The color tools, such as
Brightness/Contrast, Hue/Saturation, etc, do not operate on indexed
images. There are a few plug-ins that do so, including the
“ Normalize ” , “ VColor Enhance ” , and
“ Stretch Contrast ” operations, and it is possible to
create others as well.
Note
If you paint an indexed image with a color which is not in the
Colormap, GIMP will use the most similar color of the Colormap.
2.4.4. The Colormap context menu
Right-clicking on a color in the Colormap selects this color and opens
a pop-up submenu:
Figure 15.15. The Colormap context menu Edit color
This command opens a color selector which allows you to modify
the color .
Add Color from FG
This command is enabled only if the indexed palette contains less
than 256 colors. The background color of the Toolbox is appended
to the color map.
Add Color from BG
This command is enabled only if the indexed palette contains less
than 256 colors. The background color of the Toolbox is appended
to the color list.
Rearrange Colormap
Rearrange Colormap: This command is described in
Section 8.19, “Rearrange Colormap” .
2.3. Paths Dialog 2.5. Histogram dialog
 Report an error in Bugzilla  Appendix B. Reporting Bugs and Requesting Enhancements Appendix B. Reporting Bugs and Requesting Enhancements  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Appendix B. Reporting Bugs and Requesting Enhancements Table of Contents 1. Making sure it's a Bug 2. Reporting the Bug 3. What Happens to a Bug Report after you Submit it
Sad to say, no version of GIMP
has yet been absolutely perfect. Even sadder, it is likely that no version
ever will be. In spite of all efforts to make everything work, a program
as complicated as GIMP
is bound to screw things up occasionally, or even crash.
But the fact that bugs are unavoidable does not mean that they should be
passively accepted. If you find a bug in GIMP , the
developers would like to know about it so they can at least try to fix it.
Suppose, then, that you have found a bug, or at least think you have: you
try to do something, and the results are not what you expect. What should
you do? How should you report it?
Tip
The procedure for making an enhancement
request —that is, for asking the developers to add a
missing feature—is nearly the same as the procedure for reporting
a bug. The only thing you do differently is to mark the report as an
“ enhancement ” at the appropriate stage, as described below.
In common with many other free software projects,
GIMP uses a bug-reporting mechanism called
Bugzilla .
This is a very powerful web-based system, capable of managing thousands
of bug reports without losing track. In fact, GIMP
shares its Bugzilla database with the entire Gnome project. At the time
this is being written, Gnome Bugzilla contains 148632 bug reports–no, make
that 148633.
1. Making sure it's a Bug
The first thing you should do, before reporting a bug, is to make
an effort to verify that what you are seeing really
is a bug. It is hard to give a method for
doing this that applies to all situations, but reading the
documentation will often be useful, and discussing the question on
IRC or a mailing list may also be quite helpful. If you are
seeing a crash , as opposed to mere
misbehavior, the odds that it is a true bug are pretty high: well
written software programs are not designed to crash under
any circumstances. In any case, if you have
made an conscientious effort to decide whether it is really a bug,
and at the end still aren't sure, then please go ahead and report
it: the worst that can happen is that you will waste a bit of
time for the development team.
Note
Actually there are a few things that are known to cause
GIMP to crash but have turned out to be too
inconvenient to be worth fixing. One of them is asking
GIMP to do something that requires vast amounts of
memory, such as creating an image one million pixels on a side.
You should also make sure that you are using an up-to-date version
of GIMP : reporting bugs that have already been
fixed is just a waste of everybody's time. ( GIMP 1
is no longer maintained, so if you use it and find bugs, either
upgrade to GIMP 2 or live with
them.) Particularly if you are using the development version of
GIMP , make sure that you can see the bug in the
latest release before filing a report.
If after due consideration you still think you have a legitimate
bug report or enhancement request, the next step is to go to
GIMP 's bugzilla query page
( http://bugzilla.gnome.org/query.cgi ),
and try to see whether somebody else has already reported the same
thing.
There are two forms you can use for searching bugs: a simple form to
“ Find a Specific Bug ” , and an “ Advanced
Search ” .
Find a Specific Bug Figure B.1. Bugzilla: Find a Specific Bug Searching for bugs using the simple bug search form
Using this form, you first should select the
Product “ GIMP ” (classified as
“ Other ” ) using the drop down list. Then you just have to
enter some (space separated) search terms, e.g.
filter crash
in the text box and click on Search .
The Advanced Bug Search Form
The alternative form, the advanced query page, allows you to search
the bug database in a variety of ways :
Figure B.2. Bugzilla: Advanced Search
Searching for bugs using the advanced bug search form
Unfortunately this page is a bit more “ complicated ” to
use than it really ought to be (at least, some items are hyperlinks
leading to detailed help), but here is basically what you should do:
Summary
Set this to “ contains any of the words/strings ” .
In the adjoining text box, give one or more words that somebody
would be likely to use in writing a one-sentence summary of a
bug similar to yours. For example, if the problem is that
zooming too much causes GIMP to crash, the
word “ zoom ” would be good.
Classification
Other (since GIMP is not part of the GNOME
Desktop suite).
Product
Set this to “ GIMP ” (or “ GEGL ” ,
“ GIMP-manual ” etc., if appropriate).
Component, Version, Target Milestone Don't do anything for these. Comment, Whiteboard, Keywords
For now, leave this alone. If your search does not turn up
anything, it might be worth entering your search terms in the
“ Comment ” area here, but this often turns out to
give you either great masses of stuff or nothing.
Status
This field encodes the status of a bug report : whether it is
still open, has been resolved, etc. You want to see all relevant
bug reports, regardless of status, so you should hold down the
mouse and sweep it across all entries. Leaving it alone will not
work.
Resolution, Severity, Priority, OS
Usually you shouldn't touch these items.
(Any other items) Don't do anything for these.
When you have set these things up, click on the “ Search ”
button at either the top or bottom; they both do the same thing. The
result is either a list of bug reports – hopefully not too long
– or a message saying “ Zarro boogs found ” . If you
don't find a related bug report by doing this, it may be worth trying
another search with different terms. If in spite of your best efforts,
you file a bug report and it ends up being resolved as
“ Duplicate ” , don't be too upset: it has happened
repeatedly to the author of this documentation, who works with
GIMP Bugzilla nearly every day.
Tip
Depending on your browser configuration (i.e. whether JavaScript is
enabled), you may see a link
Give me some help . If you click
on this link, the page will be reloaded and then moving the mouse
pointer over an input widget produces a little help popup.
7. What's New in GIMP 2.6? 2. Reporting the Bug
 Report an error in Bugzilla  3. The One to Change the World 3. The One to Change the World Appendix A. GIMP History  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. The One to Change the World Version 1.0 GIMP version 1.0 was released on June 5,
1998. Finally, GIMP was
considered stable enough to warrant a worldwide announcement and
professional use.
Version 1.2 GIMP version 1.2.0 was released on
December 25, 2000.
Compared to the version 1.0, it included mostly fixes
and improvements of the user interface.
2. The Early Days of GIMP 4. Version 2.0
 Report an error in Bugzilla 
4. Version 2.0 4. Version 2. 0 Appendix A. GIMP History  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. Version 2.0
First, a statistic: the GIMP code base
contains about 230,000 lines of C code, and
most of these lines were rewritten in the
evolution from 1.2 to 2.0. From the user's point of view, however,
GIMP 2 is fundamentally similar to
GIMP 1; the features are similar enough that
GIMP 1 users won't be lost. As part of the
restructuring work, the developers cleaned up the code greatly, an
investment that, while not directly visible to the user, will ease
maintenance and make future additions less painful. Thus, the
GIMP
2 code base is significantly better organized and more
maintainable than was the case for GIMP 1.2.
Basic tools
The basic tools in GIMP 2 are not very
different from their predecessors in
GIMP 1. The
“ Select Regions by Color ” tool
is now shown in the GIMP toolbox, but
was already included in GIMP 1 as a
menu option in the Select menu. The Transform
tool has been divided into several specialized tools:
Rotation, Scale, Shearing and Perspective. Color operations
are now associated with layers in the menu
Layer → Colors ,
but this is merely a cleanup: they were already present in
the Image menu (illogically, since they are layer
operations). Thus no completely new tools appear in this
release, but two of the tools have been totally revamped
compared to the older versions: the Text tool and the Path
tool. More on this below.
The user interface for tools has also changed significantly.
The “ Tool Options ” dialog box was modified to
not resize
itself when a new tool is chosen. Most users felt that the
window changing size when a new tool was selected was
annoying. Now, by default the “ Tool Options ”
dialog is
constantly open and docked under the toolbox, where it can
easily be found.
Tool options
The “ Tool Options ” for many tools have new
possibilities that weren't available in
GIMP 1. Without being exhaustive,
here are the most noticeable improvements.
All selection tools now have mode buttons: Replace, Add,
Subtract and Intersect. In GIMP 1 the
only way to change the
selection mode was to use the
Ctrl or Shift
buttons, which
could get very confusing because those buttons also had
other functions. For example, pressing and holding the
Shift
key while using the Rectangle selection tool forces the
rectangle to be a square. Thus, to add a square selection
you would first press Shift , then click
the mouse, then release Shift , then press
Shift again, then sweep out the
selection with the mouse, then release Shift .
It can now be done more easily.
For transformation tools, buttons now control which object
(layer, selection or path) is affected by the
transformation. You can for example transform a rectangular
selection to various quadrilateral shapes. Path
transformation in particular is now easier than it was
before.
“ Fade out ” and
“ Paint Using Gradient ” are now available for
all drawing tools. In fact, all drawing tools now have their
own individual brush, gradient and pattern settings, in
contrast to GIMP 1 where there was a
single global setting
that applied to all drawing tools. Now you can select
different brushes for the Pencil and the Paint Brush, or
different patterns for the Clone and Fill tools. You can
change these setting by using your mouse wheel over the
relevant resource button (this is most useful for quickly
and easily choosing a brush).
User Interface
The most visible changes in GIMP 2
concern the user interface. GIMP now
uses the GTK2+ graphical toolkit in
place of GTK+ . One of the nice features
brought by the new
libraries is dockable dialogs, and tab navigation between
dialogs docked in the same window — a feature present in
several popular web browsers. GIMP 1
was famous for opening dialogs anywhere on your screen;
GIMP 2 can be told to use
fixed boxes. Dialogs now include a little tab-customization
menu, which provides maximum flexibility in organizing your
workspace.
The Image window has some interesting new features. These
are not necessarily activated by default, but they can be
checked as options in the
Preferences → Interface → Image Windows
menu. “ Show Brush Outline ” , for example,
allows you
to see the outline of the brush when using drawing tools. In
the “ Appearance ” sub-section, you can toggle
whether a menu
bar is present at the top of image windows. You can set an
option to work with the new fullscreen mode. Viewing options
are also available from all image windows using right click
to bring up the menu, then selecting “ View ” .
The so-called “ image ” menu is also available
by clicking on a little
triangle in the top left corner of the drawing space. The
setting you choose in the “ Preferences ”
dialog is used as
the default value, and options you set from an image are
used only for that image. (You can also toggle fullscreen
mode by using the F11 key; the
Esc key also exits fullscreen mode).
GIMP
2 features keyboard accelerators to ease menu access. If you
find that navigating through menus using your mouse is
onerous, the solution may be to use the keyboard. For
example, if the menu bar is present, to create a new image
just hit
Alt + F + N . Without the menu bar, hit
Shift + F10
to open the top-left menu, and use direction keys or
F then N
to create the new image. Keyboard accelerators are different
from shortcuts: accelerators are useful to navigate through
menus, whereas shortcuts call a specific menu item directly.
For example,
Ctrl + N
is a shortcut, and the quickest way to open a new image.
To ease access to your most commonly used menu items, the
GIMP has provided dynamic shortcuts for
many years. When a
menu is open, you can hover over the desired menu item and
hold down your shortcut combination. This feature is still
present, but is deactivated by default in the
GIMP 2.0 , to
avoid accidental re-assigning of existing shortcuts.
The GIMP also ships with a number of
sets of key-bindings
for its menus. If you would like to replace the default
GIMP
keybindings by Photoshop bindings, for example, you can move
the file menurc in your user data
directory to oldmenurc , rename
ps-menurc to
menurc and restart
GIMP .
Handling Tabs and Docks
The GIMP
2.0 introduces a system of tabbed dialogs to allow you to make your
workspace look the way you want it to be. Almost all dialogs can be
dragged to another dialog window and dropped to make a tabbed dialog
set.
Furthermore, at the bottom of each dialog, there is a dockable area:
drag and drop tabs here to attach dialogs beneath the bottom tab
group.
Scripting “ Python-fu ” is now the standard external
scripting interface for GIMP 2. This
means that you can now use GIMP
functions in Python scripts, or
conversely use Python to write
GIMP plug-ins. Python
is relatively easy to understand even for a
beginner, especially in comparison to the
Lisp-like Scheme
language used for Script-Fu in GIMP 1.
The Python bindings
are augmented by a set of classes for common operations, so
you are not forced to search through the complete
GIMP
Procedural Database in order to carry out basic operations.
Moreover, Python has integrated
development environments and
a gigantic library, and runs not only on
Linux but also on
Microsoft Windows and Apples Mac OS X. The biggest drawback,
for GIMP 2.0, is that the standard user
interface offered in
Python-fu does not use the complete power of the
Python
language. The interface is currently designed to support
simple scripts, but a more sophisticated version is a goal
of future development.
GIMP -Perl is no longer distributed with
the standard GIMP 2
distribution, but is available as a separate package.
Currently, GIMP -Perl is supported only
on Unix-like
operating systems. It includes both a simple scripting
language, and the ability to code more polished interfaces
using the Gtk2 perl module. Direct
pixel manipulation is
available through the use of PDL .
Script-Fu, based on “ Scheme ” ,
has the same drawbacks as before: not intuitive, hard to use
and lacking a real development environment. It does, however,
have one major advantage compared to Python-fu: Script-Fu
scripts are directly interpreted by GIMP
and do not require any additional software installation.
Python-fu requires that you install a package for the Python
language.
The Text Tool
The big problem with the standard text tool in
GIMP
1 was that text could not be modified after it was rendered.
If you wanted to change anything about the text, all you could
do was “ undo ”
and try again (if you were lucky enough to have sufficient
undo history available, and then of course you would also undo
any other work you had done in the meantime). In
GIMP 1.2 there was also a
“ dynamic text ”
plug-in that allowed you to create special text layers and
keep them around indefinitely, in a modifiable form, but it
was buggy and awkward to use. The second generation Text tool
is an enhanced combination of the old Text tool and the
Dynamic Text plugin. Now all options are available in the
“ Tool Options ”
: font, font size, text color, justify, antialiasing, indent,
spacing. To create a new text item, click in the image and a
little editor pops up. Text appears on the image while you are
editing (and carriage returns are handled properly!). A new
dedicated layer is created; this layer resizes dynamically to
match the text you key in. You can import plain text from a
file, and you can even do things like writing from right to
left in Arabic. If you select a text layer, clicking on it
opens the editor, and you can then modify your text.
The Path Tool
The second generation Path tool has a completely new interface. The
first major difference you notice is that paths are no longer
required to be closed. A path can be made up of a number of disjoint
curve segments. The next major difference is that now the path tool
has three different modes, Design, Edit and Move.
In Design mode, you can create a path, add nodes to an
existing path and modify the shape of a curve either by
dragging edges of the curve or dragging the
“ handles ” of a node.
In Edit mode, you can add nodes in the middle of curve edges, and
remove nodes or edges, as well as change the shape of the curve. You
can also connect two path components.
The third mode, Move, is, as you might expect, used to move
path components. If your path has several components, you
can move each path component separately. To move all
components at once, use the Shift key.
Two other path-related features are new in the
GIMP 2.0 . The GIMP
can not only import an SVG image as a raster image, but
can also keep SVG paths intact as GIMP
paths. This means that the GIMP is now
more able than ever to complement your
favorite vector drawing tool. The other feature which has
made the path tool much better is the introduction of
vector-based stroking. In previous versions, stroking paths
and selections was a matter of drawing a brush-stroke along
the path. This mode is still available, but it is now
possible to stroke a curve accurately, using the vector
library libart .
Other improvements Some other improvements in brief:
Higher-quality antialiasing in some places — most notibly in the
Text tool.
Icons and menus are skinnable. You can create your own
icon set and apply it to the toolbox using the
Preference → Interface
menu option. A theme called “ small ” is
included with the standard distribution.
An image can be saved as a template and used to create new
images.
There are four new combination modes for layers that lie
one on top of another within an image:
“ Hard Light ” , “ Soft Light ” ,
“ Grain Extract ” and
“ Grain Merge ” .
If there is an active selection , you can crop the image
directly to the selection size using image menu
Image → Crop .
As well as being able to create guides, there's now a grid
functionality in GIMP .
It is complementary to the guides functionality and makes it
easier to position objects so that they align perfectly.
The Layers dialog is more coherent, in that there are no more
hidden functions accessed only with right click on the miniature
image of the layer that appears there. You can now handle layer
operations directly from the image menu: Layer Mask,
Transparency, Transformation and Layer Color operations are
directly in the Layer submenu.
Color display filters are now available from the image
menu
View → Display Filters .
Using them, you can
simulate different gamma values, different contrasts, or
even color deficient vision, without altering your
original image. This actually has been a feature of the
GIMP developer versions for a long
time, but it has never been stable enough to appear in
a stable version of the GIMP before.
The color selection dialog has a new CMYK mode, associated with
the printer icon.
Data stored in EXIF
tags by digital cameras are now handled in read and write mode
for JPEG files.
MNG animations are now supported. The MNG file format can be
considered as animated PNG. It has all the advantages of PNG
over GIF, such as more colors, 256 levels of transparency, and
perhaps most importantly, lack of patent encumbrance. The format
is a web standard and all recent popular web browsers support
it.
The GIMP Animation package now does
onion-skinning, a
bluescreen feature was added as well as audio support.
A channel mixer filter, previously available from the web as an
add-on, appears in
Filters → Colors .
3. The One to Change the World 5. What's New in GIMP 2.2?  Report an error in Bugzilla  5. What's New in GIMP 2.2? 5. What's New in GIMP 2.2? Appendix A. GIMP History  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. What's New in GIMP 2.2?
Here is a brief summary of some of the most important new features
introduced in GIMP
2.2. There are many other smaller changes that long-time users will notice
and appreciate (or complain about!). There are also important changes at
the level of plug-in programming and script-fu creating that are not
covered here.
Interoperability and Standards Support
You can drag-and-drop or copy-and-paste image data from the
GIMP to
any application which supports image/png drops (currently
Abiword and
Kword at least) and image/xml+svg drops
( Inkscape
supports this one). So you can copy-and-paste curves into the
GIMP
from Inkscape , and then drag a
selection into Abiword to include it
inline in your document.
Patterns can now be any supported GtkPixbuf
format, including png, jpeg, xbm and others.
GIMP can load gradients from SVG files, and
palettes from ACT and RIFF files.
Drag-and-drop support has been extended. You can now drop
files and URIs onto an image window, where they will be opened
in the existing image as new layers.
Note
Please note, that Drag and Drop will not work for Apple Mac OS X
between GIMP and the finder. This is due to a lack of
functionality on Apples X11.app
Shortcut Editor
You can now edit your shortcuts in a dedicated dialog, as well as
continue to use the little-known dynamic shortcuts feature (which has
been there since 1.2).
Plug-in Previews
We have provided a standard preview widget for plug-in authors which
greatly reduces the amount of code required to support previews. David
Odin has integrated this widget into all the current filters, so that
now many more filters in the GIMP include a preview
which updates in
real time, and the various previews behave much more consistently.
Real-Time Previews of Transform Operations
The transform tools (shear, scale, perspective and rotate) can
now show a real-time preview of the result of the operation when
the tool is in “ Traditional ” mode. Previously, only a
transforming grid was shown.
GNOME Human Interface Guide Conformance
A lot of work has been done on making the GIMP 's
interface simpler and
more usable for newcomers. Most dialogs now follows the
GNOME HIG to
the best of our knowledge. In addition, dialogs have separated out or
removed many “ Advanced ” options, and replaced them with
sane defaults or hidden them in an expander.
GTK+ 2.4 Migration
Menus use the GtkUIManager to
generate menu structure dynamically from XML data files.
A completely revamped File Chooser is used everywhere in the
GIMP
for opening or saving files. The best thing about it is that it
lets you create a set of “ bookmarks ” , making it
possible to
navigate quickly and easily to commonly used directories.
GIMP now supports fancy ARGB cursors when they
are available on the system.
Basic Vector Support
Using the GFig plug-in, the GIMP now supports the
basic functionality
of vector layers. The GFig plug-in supports a number of vector
graphics features such as gradient fills, Bezier curves and curve
stroking. It is also the easiest way to create regular or irregular
polygons in the GIMP . In the
GIMP 2.2, you can create GFig layers, and
re-edit these layers in GFig afterwards. This level of vector support
is still quite primitive, however, in comparison to dedicated
vector-graphics programs such as Inkscape .
Also . . .
There are many other smaller user-visible features. A rapid-fire list
of some of those features is below.
It is now possible to run the GIMP in batch
mode without an X server.
We have a GIMP binary
( GIMP -console) which is not linked to GTK+
at all.
Improved interface for extended input devices
Editable toolbox: You can now decide which tools should be shown
in the Toolbox, and their order. In particular, you can add any or
all of the Color Tools to the Toolbox if you wish to.
Histogram overlays R, G and B histograms on the Value histogram, and
calculates the histogram only for the contents of the selection .
Shortcuts are now shared across all GIMP windows.
4. Version 2.0 6. What's New in GIMP 2.4?  Report an error in Bugzilla  6. What's New in GIMP 2.4? 6. What's New in GIMP 2.4? Appendix A. GIMP History  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. What's New in GIMP 2.4? Refreshed Look
A whole new default icon theme has been created for 2.4. The icons
comply with the Tango style guidelines so GIMP doesn't feel out of
place on any of the supported platforms. Regardless of whether you
run GIMP under Microsoft Windows, Mac OS X or Linux (GNOME, KDE or
Xfce), GIMP provides a polished, consistent look.
Figure A.1. New Look of the toolbox in GIMP 2.4
Additionally the icons also have enhanced usability on dark widget
themes, which is a common setting among digital artists.
For artists preferring more desaturated color theme for their icons
is an alternative icon theme available for download
[ JIMMAC01 ] .
Scalable Brushes
The tool options now include a brush size slider that affects both
the parametric and bitmap brushes. This has been an oft-requested
feature from both digital painters and photo editors.
Figure A.2. Scalable brushes in GIMP 2.4
Unlike previous versions of GIMP, regardless of whether you're using
a bitmap brush, parametric brush or even a picture tube (multiple
bitmaps), you can easily set the brush size with either the tool
options dock slider or an external device such as a MIDI slider or
knob or a USB device like the Griffin Powermate.
Selection Tools
The selection tools have been rewritten from scratch to allow
resizing of existing selections. Additionally the rectangular
selection tool includes a setting for creating rounded corners as
this has been identified as a very common task among web designers.
Figure A.3. Selection tools in GIMP 2.4
The learning curve for the tools has been flattened as the key
functionality is available without obscure shortcuts that confused
GIMP beginners. Most of the existing shortcuts still work, but the
functionality is either available through the tool options or made
obsolete due to the interactive move and resize on canvas.
While the tools have been redesigned to make them easier to
understand for the newbies, all the former functionality is there.
You can still constrain aspect ratios or specific sizes.
Foreground Select Tool
Selecting individual objects on images is easier now with a new
foreground select
tool . It is done in two steps. First, you make select region
of interest which contains the entire object. Then you
paint over selected area with a brush, not crossing object’s border.
Release mouse button when you’re done and look, if there are dark
blue spots on your objects. If there are some, paint with a brush
over them again and release to refine selection. When there are no
more blue areas inside the object, press Enter and there you have a
perfectly selected object.
Align Tool
While GIMP has provided a grid and guideline functionality, the
actual alignment of objects had to be done manually. A new tool
comes at rescue ...
Changes in menus
Most notable is the new top-level Color menu that accumulates most
tools, plug-ins and scripts that adjust colors in RGB/Grayscale mode
and color palettes in Indexed mode. So now you can reach functions
like Levels or Curves much faster than before, unless you define
your own keyboard shortcuts for them using the improved keyboard
shortcuts manager.
In the new version of GIMP, some menu entries have changed their
names and position. It was done mostly to simplify learning curve
and improve user experience. After all, "HSV Noise" and "RGB Noise"
sound more meaningful than "Scatter HSV" and "Scatter RGB", don't
they? And status bar hints for all plug-ins and scripts are quite
helpful too.
Support for file formats Support for Photoshop ABR brush format; Improved reading/writing EXIF in JPEG; Importing clipping paths in TIFF; Layer masks can be saved to PSD;
16/32 bit bitmaps and alpha-channel support in BMP;
24 bit and Vista icons can be opened and saved.
Fullscreen Editing
The fullscreen mode has been improved to not only allow getting a
full scale preview of the artwork, but also allow comfortable
editing. The artist has maximum screen estate available while all
functionality is quickly accessible by pressing the
Tab key (toggles
visibility of all docks) when working fullscreen.
Whether painting or touching up photos, fullscreen editing keeps all
the distracting elements out of sight on a key press. It's like
observing stars in a field as opposed to a light-polluted city.
Color Management and Soft-proofing
GIMP now provides full support for color profiles allowing precise
color modification throughout the whole
“ digital darkroom ” process.
Figure A.4. Color management in GIMP 2.4 New Crop Tool
Just like the selection tools, the new crop tool has been enhanced
since the last release. The resize handles actually resize the crop
rectangle instead of providing both resize and move functionality.
The tool behaves more naturally and consistently with other GIMP
tools. For details see Section 4.4, “Crop” .
To move, simply drag the rectangle clicking within the area.
Resizing is possible in one or two axes at the same time dragging
the handle-bars on the sides and corners. The outside area is
darkened with a nice passepartout effect to better get the idea of
how the final crop will look like.
Red Eye Removal
While numerous red-eye workflows exist already, GIMP now features a
very convenient auto-magic filter to remove red eye from your shots.
Healing Brush
The healing brush is a new tool, similar in the working of the
clone tool, that permits to quickly fix small defects or
imperfections due to scratching or dust. In fact the tool is smart
enough to being able to understand where and
how to modify an image to cure these defects based on image color
context.
Perspective Clone
Here is another clone-like new tool that is able to adapt the
destination geometry, instead of color as does the healing brush,
based on preselected distortion settings. As the name suggests,
perfect when copying images blocks with some type of prospective
changes.
Lens Distortion
A very common problem exposing itself especially when using cheaper
lenses is barrel distortion and vignetting. Luckily GIMP provides a
brand new filter to compensate for both problems. Saving
photographer's pocket is our mission!
Various Other Improvements
In addition to all the above, GIMP has been improved in other areas
such as:
Better status information for tools in the window status bar.
Various speedups in composing functions and gradient drawing.
Zoomable preview widget for plugins. 5. What's New in GIMP 2.2? 7. What's New in GIMP 2.6?  Report an error in Bugzilla  7. What's New in GIMP 2.6? 7. What's New in GIMP 2.6? Appendix A. GIMP History  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. What's New in GIMP 2.6?
GIMP 2.6 is an important release from a development point of view . It
features changes to the user interface addressing some often received
complaints, and a tentative integration of GEGL, the graph based image
processing library that will eventually bring high bit-depth and
non-destructive editing to GIMP.
User Interface Toolbox Menubar removed
The toolbox menubar has been removed and merged with the image
window menubar. To be able to do this a window called the empty
image window has been introduced. It hosts the menubar and keeps
the application instance alive when no images are opened. It also
acts as a drag and drop target. When opening the first image the
empty image window is transformed into a normal image window, and
when closing the last image, that window becomes the empty image
window.
Figure A.5. New Look of the image window in GIMP 2.6 Toolbox and docks are utility windows
With the empty image window acting as a natural main window, the
Toolbox and Docks windows are now utility windows rather than main
windows. This enables window managers to do a much better
job of managing the GIMP windows, including omitting the Toolbox
and Docks from the taskbar and ensuring that the Toolbox and Docks
always are above image windows.
Ability to scroll beyond image border
The Navigation dialog now allows panning beyond the image border;
so it is no longer a problem to use a brush on the edge of
an image that fills the entire display window. Also, if a utility
window covers the image, you can pan the image to view or edit the
portion covered by the utility window.
Figure A.6. Scrolling beyond border Minor changes
Renamed Dialogs menu to Windows.
Keep a list of recently closed Docks and allow reopening them.
Make opening images in already running GIMP instances work better
on Windows.
You can now enter the image zoom ratio directly in the status bar.
Added support for using online help instead of a locally
installed GIMP Help package.
Make it possible to lock tabs in docks to prevent accidental
moving.
Tools, Filters and Plug-ins Improved Free Select Tool
The freehand select tool has been enhanced to support polygonal
selections. It also allows mixing free hand segments with polygonal
segments, editing of existing segments, applying angle-constraints
to segments, and of course the normal selection tool operations
like add and subtract. Altogether this ends up making the Free
Select Tool a very versatile, powerful and easy-to-use selection
tool.
Figure A.7. Polygonal Selection Brush Dynamics
Brush dynamics uses an input dynamic such as pressure, velocity, or
random, to modify brush parameters such as opacity, hardness, size,
or color; every brush supports size and opacity, most support more.
Velocity and random are usable with a mouse. The Ink tool, that
supported velocity, has been overhauled to better handle
velocity-dependent painting.
Figure A.8. Brush Dynamics
Brush dynamics have enabled a new feature in stroking paths. There
is now a check box under the “ paint tool ” option, for
emulating brush dynamics if you stroke using a paint tool. What this
means is that when your stroke is painted, GIMP tells
the brush that the pressure and velocity are varying along the
length of the stroke. Pressure starts with no pressure, ramps up to
full pressure, and then ramps down again to no pressure.
Velocity starts from zero and ramps up to full speed by the end of
the stroke.
Minor changes
Added a bounding box for the Text Tool that supports automatic
wrapping of text within that bounding box.
Figure A.9. Text tool bounding box
Move handles for rectangle based tools like Crop and Rectangle
Select to the outside of the rectangle when the rectangle is
narrow.
Figure A.10. Rectangle handles
Added motion constraints to the Move Tool.
Improved event smoothing for paint tools.
Mark the center of rectangles while they are moved, and snap
the center to grid and rulers.
Enable brush scaling for the Smudge tool.
Added ability to save presets in all color tools for color
adjustments you use frequently.
Allow to transfer settings from Brightness-Contrast
to Levels , and from
Levels to Curves .
Allow changing opacity on transform tool previews.
The Screenshot plug-in has been given the ability to capture
the mouse cursor (using Xfixes).
Display aspect ratio of the Crop and Rectangle Select Tool
rectangles in the status bar.
Desaturate has been given an on-canvas preview.
The Flame plug-in has been extended with 22 new variations.
Data file folders like brush folders are searched recursively
for files.
Replaced the PSD import plug-in with a rewritten version that
does what the old version did plus some other things, for
example reading of ICC color profiles.
Several displays use Cairo library. Figure A.11. Comparing 2.6 display vs 2.4 Under the Hood GEGL
Important progress towards high bit-depth and non-destructive
editing in GIMP has been made. Most color operations in GIMP are
now ported to the powerful graph based image processing framework
GEGL [ GEGL ] , meaning that the
internal processing is done in 32bit floating point linear
light RGBA. By default the legacy 8bit code paths are still used,
but a curious user can turn on the use of GEGL for the color
operations with Colors / Use
GEGL .
In addition to porting color operations to GEGL, an experimental
GEGL Operation tool has been added , found in the Tools menu. It
enables applying GEGL operations to an image and it gives on-canvas
previews of the results. The screenshot below shows this
for a Gaussian Blur.
Figure A.12. GEGL operation Minor changes
Ported many widgets to use the 2D graphics library cairo
[ CAIRO ] for drawing. See this
comparison for an
example of how much better this looks.
Miscellaneous Plug-in Development
There are new things for a plug-in developer to enjoy as well.
For example, procedures can now give a detailed error
description in case of an error, and the error can be propagated
to the user.
GIMP 2.6 also further enhances its scripting abilities. In
particular there is now a much richer API for the creation and
manipulation of text layers. Here is a list of new symbols in GIMP
2.6 : [ GIMP-NEWSYM26 ] .
Backwards Compatibility
Some old scripts could not be used with GIMP-2.4. This has been
improved and 2.6 should run 2.0 and 2.2 scripts.
Known Problems
The Utility window hint is currently only known to work well in
the Linux GNOME desktop environment and on Windows starting with
GIMP 2.6.1.
Using the Text Tool is currently not an optimal experience.
Making it work better is a goal for GIMP 2.8.
If you build GIMP yourself and don't have GVfs support on your
platform you need to explicitly pass
--without-gvfs to configure ,
otherwise opening remote files will not work properly.
6. What's New in GIMP 2.4? Appendix B. Reporting Bugs and Requesting Enhancements  Report an error in Bugzilla  2. The Early Days of GIMP 2. The Early Days of GIMP Appendix A. GIMP History  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. The Early Days of GIMP Version 0.54
Version 0.54 was released in February 1996, and had a major impact
as the first truly professional free image manipulation program.
This was the first free program that could compete with the big
commercial image manipulation programs.
Version 0.54 was a beta release, but it was so stable that you
could use it for daily work. However, one of the major drawbacks
of 0.54 was that the toolkit (the slidebars, menus, dialog boxes,
etc.) was built on Motif, a commercial
toolkit. This was a big drawback for systems like
“ Linux ” , because you had to buy
Motif if you wanted to use the faster,
dynamically linked GIMP . Many
developers were also students running Linux,
who could not afford to buy Motif.
Version 0.60
When 0.60 was released in July 1996, it had been under S and P
(Spencer and Peter) development for four months. Main programming
advantages were the new toolkits, GTK
( GIMP Toolkit) and gdk
( GIMP Drawing Kit), which eliminated the
reliance on Motif. For the
graphic artist, 0.60 was full of new features like: basic layers;
improved painting tools (sub-pixel sampling, brush spacing); a
better airbrush; paint modes; etc.
Version 0.60 was only a developer's release, and was not intended
for widespread use. It served as a workbench for 0.99 and the
final 1.0 version, so functions and enhancement could be tested
and dropped or changed. You can look at 0.60 as the alpha version
of 0.99.
Version 0.99
In February 1997, 0.99 came on the scene. Together with other
developers, S and P had made several changes to
GIMP and added
even more features. The main difference was the new API
(Application Programming Interface) and the
“ PDB ” , which made it possible to write scripts;
Script-Fus (or
macros) could now automate things that you would normally do by
hand. GTK/gdk had also changed and was now
called GTK+ . In
addition, 0.99 used a new form of tile-based memory handling that
made it possible to load huge images into GIMP
(loading a 100 MB image into GIMP is no
problem). Version 0.99 also introduced a new
native GIMP file format called XCF.
The new API made it really easy to write extensions and plug-ins
for GIMP . Several new plug-ins and extensions
emerged to make GIMP
even more useful (such as SANE , which enables
scanning directly into GIMP ).
In the summer of 1997, GIMP had reached
version 0.99.10, and S and
P had to drop most of their support since they had graduated and
begun jobs. However, the other developers of
GIMP continued under
the orchestration of Federico Mena to make
GIMP ready for prime time.
GTK+ was separated from
GIMP in September 1997.
GTK+ had been
recognized as an excellent toolkit, and other developers began
using it to build their own applications.
GIMP went into feature freeze in October
1997. This meant that no
new features would be added to the GIMP
core libraries and program. GUM (GIMP Users
Manual) version 0.5 was also released early in October 1997.
The developing work continued to make GIMP
stable and ready for version 1. 0.
Appendix A. GIMP History 3. The One to Change the World  Report an error in Bugzilla 
Appendix A. GIMP History Appendix A. GIMP History  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Appendix A. GIMP History Table of Contents 1. The Very Beginning 2. The Early Days of GIMP 3. The One to Change the World 4. Version 2.0 5. What's New in GIMP 2.2? 6. What's New in GIMP 2.4? 7. What's New in GIMP 2.6? 1. The Very Beginning
According to Peter Mattis and Spencer Kimball , the original creators of
GIMP , in their announcement of GIMP
0.54:
The GIMP arose from the ashes of a hideously
crafted CS164 (compilers)
class project. The setting: early morning. We were both weary from lack
of sleep and the terrible strain of programming a compiler in
LISP. The limits of our patience had long been
exceeded, and yet still the dam held.
And then it happened. Common LISP
messily dumped core when it could not allocate the 17 MB it needed to
generate a parser for a simple grammar using yacc .
An unbelieving moment passed, there was one shared look of disgust,
and then our project was vapor. We had to write something...
ANYTHING ... useful. Something in
C. Something that did not rely on nested lists to
represent a bitmap. Thus, the GIMP was born.
Like the phoenix, glorious, new life sprung out of the burnt remnants of
LISP and yacc . Ideas went
flying, decisions were made, the
GIMP began to take form.
An image manipulation program was the consensus. A program that would at
the very least lessen the necessity of using commercial software under
“ Windoze ” or on the “ Macintoy ” . A program
that would provide the features missing from the other
X painting and imaging tools. A program
that would help maintain the long tradition of excellent and free
UNIX applications.
Six months later, we've reached an early beta stage. We want to release
now to start working on compatibility issues and cross-platform
stability. Also, we feel now that the program is actually usable and
would like to see other interested programmers developing plug-ins and
various file format support.
Bibliography 2. The Early Days of GIMP  Report an error in Bugzilla 
2. What's New in GIMP 2.8? 2. What's New in GIMP 2.8? Chapter 1. Introduction  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. What's New in GIMP 2.8? GIMP 2.8 is another important release from a
development point of view , even more that it was for 2.6. It
features a big change to the user interface addressing one of the
most often received complaints: the lack of a single window
mode. Moreover the integration effort of GEGL library had taken a
big step forward, reaching more than 90% of the
GIMP core, a new powerful transformation tool,
layer groups, new common options, new brushes, improved text tool,
and more.
User Interface New single window mode
With this new feature it will be possible to work with all
the GIMP dialogs inside one big window,
usually with the image(s) centered inside. No more floating
panels or toolbox but the dialogs could be arranged inside
this single window. This mode could be enabled or disabled
all the time, even while working, and the option will be
remembered through the sessions.
Figure 1.1. The new look of the single window mode New file save workflow
Now Save and Save as work only with xcf formats. If you
want to export an image in another format, say jpg or png,
you have to explicitly Export it. This enhances the workflow
and lets you simply overwrite the original file or export to
various other formats.
Figure 1.2. The new image workflow New image bar
A new useful image bar comes with the single window mode,
which lets you switch easily between open images through the
means of a tab bar with image thumbnails.
Figure 1.3. The new image bar New arrangement options GIMP will make users working with two screens
(one for dialogs, the other for images )
happy: now it is possible to arrange the dialogs one over the other,
in tabs and in columns too.
Figure 1.4. Multi column docks New resources tags GIMP Brushes, Gradients, Pattern and
Palettes can be filtered and searched via tags. Tags are
text labels that the user can assign to resources. With Tags
the user can easily find the resources by means of an input
text box. Tags can be manually assigned by the user with the
same input box used for searching tags, or they can be
automatically tagged using the directory name of the
imported items.
Figure 1.5. Resource tags Simple math in size entries
Enhancements have also been made to the size entry widget,
which is used for inputting most of the x, y, width, height
parameters. For example, in the scale dialog it is now
possible to write “ 50% ” in the Width field to
scale the image to 50% of the width. Expressions such as
“ 30in + 40px ” and “ 4 * 5.4in ”
work, too.
Figure 1.6. Math size entries Minor changes
The new “ Lock Pixels ” option in the layers
dialog can avoid undesired painting on a layer when
working with several layers.
Figure 1.7. The new Lock Pixels option
Now you can move between images in single and multi
window mode using the shortcuts
Ctrl + PageUp/PageDown
or
Alt + Number .
Add support for F2 to rename items in lists.
You can now
Alt + Click
on layers in the Layers dialog to create a selection from
it. Add, subtract and intersect modifiers
Click , Shift and
Ctrl + Shift
keys work too. This makes it easy to compose contents of a
layer based on the contents of other layers, without
detours.
Since the keyboard shortcuts
Ctrl + E
and
Ctrl + Shift + E
have been redirected to image export mechanisms, new
keyboard shortcuts have been setup for “ Shrink
Wrap ” and “ Fit in Window ” , namely
Ctrl + J
and
Ctrl + Shift + J
respectively.
Added
Windows → Hide
docks menu item that does what
“ Tab ” does and also displays its state, which
is now persistent across sessions, too.
The layer modes have been rearranged into more logical and
useful groups based on the effect they have on layers. Layer
modes that make the layer lighter are in one group, layer modes that
make the layer darker in another group, and so forth.
In multi-window mode, you can now close the Toolbox without
quitting GIMP.
Allow binding arbitrary actions to extra mouse buttons.
Now it is possible to change the application language
directly from the preference menu.
Tools, Filters and Plug-ins A new tool: Cage Transform
With this new tool is now possible to create custom bending
of a selection just moving control points.
This is the result of one of our Google Summer of Code 2010
students.
Figure 1.8. Cage Transform Improved Text Tool
The text tool has been enhanced to support on canvas text
writing and make possible changing the attributes of a single char.
Figure 1.9. Improved text tool New layer groups
It is now possible to group set of layers and treat them
like an entity. It is possible to switch a group on or off and
to move the group in the layers dialog. It is easy to add /
remove existing layers to a group or to create / delete a
layer inside the group and it is even possible to create
embedded groups of groups. It is possible to apply a
layer mode to a group as you do with a single layer. All this greatly
improves the workflow with complex multilayer images making
them easier to manage.
Figure 1.10. New layer groups Rotating brushes
Brushes can now be rotated at will, acting on the brush
option “ Angle ” .
Figure 1.11. Rotating brushes Minor changes
The default Quick Mask color is now configurable.
The RTL mode (right to left writing) has been improved in the Text
tool.
You can specify the written language in the Text
Tool. This helps choosing an appropriate font, or
appropriate glyphs for the selected language.
Added optional diagonal guides to the crop tool.
Added “ Rule of fifths ” crop guide overlay.
A Cairo based PDF exporter has been implemented. Although being
somewhat simplistic, the exporter saves text, embedding
fonts into the final PDF file, and attempts to convert
bitmaps to vector objects.
Brush dynamics improved.
Added plug-in for loading JPEG2000 images.
Added plug-ins for X11 Mouse Cursor import and export
support.
Added fundamental OpenRaster (.ora) import and export
support.
Added RGB565 support to the csource plug-in.
Added a new “ Create ” command that allows loading
a Web page directly into GIMP using Webkit.
Under the Hood GEGL
The porting of the GIMP core towards the
new high bit-depth and non-destructive editing GEGL [ GEGL ] library has taken big
steps and now more than 90% of the task is already finished.
In addition to porting color operations to
GEGL , an experimental GEGL Operation tool
has been added , found in the Tools menu. It enables applying
GEGL operations to an image and it gives
on-canvas previews of the results. The screenshot below
shows this for a Gaussian Blur.
Figure 1.12. GEGL operation Cairo porting
Started with GIMP version 2.6, all tools rendering
on canvas is now completely ported to [ CAIRO ] . It provides smooth
antialiased graphics and improves GIMP look. Some
plug-ins have been upgraded to Cairo as well. Additionally
all tools now use an on-canvas progress indicator instead of
the one in the statusbar.
Figure 1.13. Progress indicator Miscellaneous License change
The GIMP license has been changed to (L)GPLv3+.
New script API
A lot of GIMP APIs have been rebuilt to simplify
developing new scripts.
To further enhances scripting abilities, API changes to support
layer groups have been made.
Backwards Compatibility
To allow migrating from the old tools presets
system to the new one, there is a Python script ,
which you can download from the GIMP wiki
site. However, the old tools presets are not 100%
convertible to the new tool presets. For instance, brush
scale from 2.6 can't be converted to brush size in 2.8.
Known Problems
Working with graphics tablets could be problematic due to
the GTK+2 library in use. If in this case either use the
older version 2.6 or wait for the up coming version 3.0
for the full GTK+3 support.
Chapter 1. Introduction Chapter 2. Fire up the GIMP  Report an error in Bugzilla  7. 33. Add Alpha Channel 7. 33. Add Alpha Channel 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 33. Add Alpha Channel Add Alpha Channel : An alpha channel is
automatically added into the Channel Dialog as soon as you add a second
layer to your image. It represents the transparency of the image. If your
image has only one layer, this background layer has no Alpha channel . In
this case, you can Add an Alpha channel with this command.
 7. 33. 1. Activate the Command
You can access this command from the image menubar through
Layer → Transparency → Add alpha Channel .
In addition, at the
Layer Dialog , you
can access it through Add Alpha Channel
of its context pop-up menu .  7. 32.
The “ Transparency ” Submenu of the “ Layer ” menu
7.34. Remove Alpha Channel
 Report an error in Bugzilla  7. 34. Remove Alpha Channel 7.34. Remove Alpha Channel 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 34. Remove Alpha Channel
This command removes the Alpha channel of the active layer , keeping the
Apha channels of the other layers.
If the active layer is the background layer and if you have not added an
Alpha channel before (then the layer name is in bold letters in the
Layer Dialog), the command is grayed out, inactive.
If the active layer is not the background layer, transparency is replaced
with the background color of the Toolbox.
 7. 34. 1. Activate the Command
You can access this command from the image menubar through
Layer → Transparency → Remove Alpha Channel .
In addition, at the
Layer Dialog , you
can access it through Remove Alpha Channel
of its context pop-up menu .  7. 33. Add Alpha Channel 7. 35. Color to Alpha
 Report an error in Bugzilla  7. 39. Add Alpha channel to Selection 7.39. Add Alpha channel to Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 39. Add Alpha channel to Selection
The Add to Selection command
creates a selection in the current layer from the Alpha Channel. Opaque
pixels are fully selected, transparent pixels are unselected, and
translucent pixels are partially selected. This selection is added to the existing selection. The alpha channel
itself is not changed.
The other commands in this group of operations are similar, except that
instead of adding to the existing selection with the selection produced
from the active layer, they either completely replace the selection
with a selection produced from the alpha selection, subtract the alpha
selection from the existing selection, or create a selection that is
the intersection of the two.
 7. 39. 1. Activate the Command
You can access this command from the image menubar through
Layer → Transparency → Add to Selection .  7. 39.2. Example Figure 16.104. Applying “ Add to Selection ”
Non-transparent pixels of the active layer have been added
to the existing selection.
7.38. Alpha to Selection 7. 40. Subtract from Selection
 Report an error in Bugzilla 
7. 41. Intersect Alpha channel with Selection 7.41. Intersect Alpha channel with Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 41. Intersect Alpha channel with Selection
The Intersect with Selection command creates a
selection in the current layer from the Alpha Channel. Opaque pixels are
fully selected, transparent pixels are unselected, and translucent pixels
are partially selected. This selection is intersected
with the existing selection: only common parts of both selections are
kept. The alpha channel itself is not changed.
 7. 41. 1. Activate the Command
You can access this command from the image menubar through
Layer → Transparency → Intersect with Selection ,
or from the pop-up menu which appears when you right-click on the
active layer in the Layers Dialog.  7. 41.2. Example Figure 16.106. Applying “ Intersect with Selection ”
Non-transparent pixels of the active layer have been intersected
with the existing rectangular selection.
7. 40. Subtract from Selection 7.42. The “ Transform ” Submenu
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7. 38. Alpha to Selection 7.38. Alpha to Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 38. Alpha to Selection
The Alpha to Selection command creates a
selection in the current layer from the alpha channel, which encodes
transparency. Opaque areas are fully selected, transparent areas are
unselected, and translucent areas are partially selected. This selection
replaces the existing selection. The alpha channel
itself is not changed.
The other commands in this group of operations are similar,
except that instead of completely replacing the existing selection with
the selection produced from the alpha channel, they either add the two
selections, subtract the alpha selection from the existing selection, or
create a selection that is the intersection of the two.
 7. 38. 1. Activate the Command
You can access this command from the image menubar through
Layer → Transparency → Alpha to Selection
or from the pop-up menu which appears when you right-click on the
active layer in the Layer Dialog.  7. 38.2. Example Figure 16.103. Applying “ Alpha to Selection ”
Non-transparent pixels of the active layer have replaced
the existing rectangular selection.
7. 37. Threshold Alpha 7.39. Add Alpha channel to Selection
 Report an error in Bugzilla  7. 40. Subtract from Selection 7.40. Subtract from Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 40. Subtract from Selection
The Subtract from Selection command
creates a selection in the current layer from the Alpha Channel. Opaque
pixels are fully selected, transparent pixels are unselected, and
translucent pixels are partially selected.This selection is subtracted from the existing selection. The Alpha
channel itself is not changed.
 7. 40. 1. Activate the Command
You can access this command from the image menubar through
Layer → Transparency → Subtract from Selection .  7. 40.2. Example Figure 16.105.
Applying “ Subtract from Selection ”
Non-transparent pixels of the active layer have been subtracted
from the existing rectangular selection.
7. 39. Add Alpha channel to Selection 7.41. Intersect Alpha channel with Selection  Report an error in Bugzilla 
7. 36. Semi-flatten 7.36. Semi-flatten 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 36. Semi-flatten
The Semi-Flatten command is described
in the Semi-flatten filter
chapter. The command is useful when you need an anti-aliased image with
indexed colors and transparency.
 7. 36. 1. Activate the Command
You can access this command from the image menubar through
Layer → Transparency → Semi-flatten .  7. 35. Color to Alpha 7. 37. Threshold Alpha  Report an error in Bugzilla  7. 6. Anchor layer 7. 6. Anchor layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 6. Anchor layer
If you have created a floating selection, a temporary layer, called a
“ floating layer ” or “ floating selection ” ,
is added to the layer stack. As long as the floating layer persists,
you can work only on it. To work on the rest of the
image, you must “ anchor ” the floating layer to the former
active layer with the Anchor layer command.
If the image does not contain a floating selection, this menu entry is
insensitive and grayed out.
Note
If there is an active selection tool, the mouse pointer is displayed
with an anchor icon when it is outside of the selection.
 7. 6. 1. Activate the Command
You can access this command from the image menubar through
Layer → Anchor layer ,
or by using the keyboard shortcut
Ctrl + H .  7. 6. 2. Alternative Ways of Anchoring a Floating Selection There are more ways to anchor a floating selection:
You can anchor the floating selection to the current layer that the
selection is originating from by clicking anywhere on the image
except on the floating selection. You can also anchor the floating selection to the current layer by
clicking on the anchor button
of the Layers dialog .
If you create a New Layer
while there is a floating selection , the floating selection is
anchored to this newly created layer.
7.5. Duplicate layer 7. 7. Merge Down
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7. 15. Select Bottom Layer 7. 15. Select Bottom Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 15. Select Bottom Layer
With the Select Bottom Layer command, you
can make the bottom layer in the stack become the active layer for
the image . It is then highlighted in the
Layers dialog . If the bottom layer of the stack is already the active
layer, this menu entry is insensitive and grayed out.
 7. 15. 1. Activate the Command
You can access this command from the image menubar through
Layer → Stack → Select Bottom Layer ,
by using the keyboard shortcut End .
Or you simply click on the layer name in the Layers Dialog.  7. 14. Select Top Layer 7. 16. Raise Layer
 Report an error in Bugzilla  7. 35. Color to Alpha 7. 35. Color to Alpha 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 35. Color to Alpha
This command is the same as
Layer → Transparency :
Section 8.34, “Color to Alpha” .
7.34. Remove Alpha Channel 7.36. Semi-flatten
 Report an error in Bugzilla  7. 53. Crop to Selection 7.53. Crop to Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 53. Crop to Selection
The Crop to Selection command crops only the
active layer to the boundary of the selection by removing any strips
at the edge whose contents are all completely unselected. Areas which
are partially selected (for example, by feathering) are not cropped.
If there is no selection for the image, the menu entry is insensitive
and grayed out.  7. 53. 1. Activating the Command
You can access this command from the image menubar through
Layer → Crop to Selection .  7. 53.2. Example Figure 16.118. Applying “ Crop to Selection ”
On the left : before applying the command, the layer has
a selection that has feathered edges.
On the right: after applying the command, the non-transparent
pixels are not cropped, even if they are only semi-transparent.
7.52. Scale Layer 7.54. Autocrop Layer  Report an error in Bugzilla  7. 8. Delete Layer 7.8. Delete Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 8. Delete Layer
The Delete Layer command deletes the current
layer from the image.
 7. 8. 1. Activate the Command
You can access this command from the image menubar through
Layer → Delete Layer .
In addition, at the
Layer Dialog , you
can access it through Delete Layer of its
context pop-up menu , or clicking on the
icon button on the bottom of this dialog.  7. 7. Merge Down 7. 9. The Text Commands of the Layer Menu
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7. 5. Duplicate layer 7.5. Duplicate layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 5. Duplicate layer
The Duplicate Layer command adds a new
layer to the image which is a nearly identical copy of the active layer.
The name of the new layer is the same as the name of the original layer,
but with “ copy ” appended to it.
If you duplicate a background layer which does not have an alpha
channel, the new layer is provided with one. In addition, if there are
any “ parasites ” attached to the active layer, they are
not duplicated. (If your understanding of the word
“ parasites ” is limited to small, unpleasant creatures,
please ignore the last sentence.)
 7. 5. 1. Activate the Command
You can access this command from the image menubar through
Layer → Duplicate Layer ,
or from the local pop-up menu that you get by right-clicking on
the Layer Dialog.
In addition, at the
Layer Dialog , you
can access it through Duplicate of its
context pop-up menu , or clicking on the
icon button on the bottom of this dialog.  7. 4. New From Visible 7. 6. Anchor layer
 Report an error in Bugzilla  8. 7. Equalize 8.7. Equalize 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8.7. Equalize
The Equalize
command automatically adjusts the brightness of colors across the active
layer so that the histogram for the Value channel is as nearly flat as
possible, that is, so that each possible brightness value appears at about
the same number of pixels as every other value. You can see this in the
histograms in the example below, in that pixel colors which occur
frequently in the image are stretched further apart than pixel colors
which occur only rarely. The results of this command can vary quite a bit.
Sometimes “ Equalize ”
works very well to enhance the contrast in an image, bringing out details
which were hard to see before. Other times, the results look very bad. It
is a very powerful operation and it is worth trying to see if it will
improve your image. It works on layers from RGB and Grayscale images. If
the image is Indexed , the menu entry is insensitive and grayed out.  8. 7. 1. Activate the Command
You can access this command from the image menubar through
Colors → Auto → Equalize
or by using the keyboard shortcut
Shift + Page_Down .  8. 7.2. “ Equalize ” example Figure 16. 132. Original image
The active layer and its Red, Green , Blue histograms before
“ Equalize ” .
Figure 16.133. Image after the command
The active layer and its Red, Green , Blue histograms after
treatment.
Histogram stretching creates gaps between pixel columns giving it
a striped look.
8.6. The “ Auto ” Submenu 8.8. White Balance
 Report an error in Bugzilla  7. 43. Flip Horizontally 7.43. Flip Horizontally 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 43. Flip Horizontally
The Flip Horizontally command reverses the
active layer horizontally, that is, from left to right. It leaves the
dimensions of the layer and the pixel information unchanged.
 7. 43. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transform → Flip Horizontally .  7. 43.2. Example Figure 16.108. Applying “ Flip Layer Horizontally ”
Before applying the command
The layer after it has been flipped. It looks
as if the image has been reflected along the central
vertical axis of the layer.
7. 42. The “ Transform ” Submenu 7.44. Flip Vertically
 Report an error in Bugzilla  7. 44. Flip Vertically 7.44. Flip Vertically 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 44. Flip Vertically
The Flip Vertically command reverses the
active layer vertically, that is, from top to bottom. It leaves the
dimensions of the layer and the pixel information unchanged.
 7. 44. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transform → Flip Vertically .  7. 44.2. Example Figure 16.109. Applying “ Flip Layer Vertically ”
Before applying the command
The layer after it has been flipped. It looks
as if the image has been reflected along the central
horizontal axis of the layer.
7. 43. Flip Horizontally 7.45. Rotate 90° clockwise
 Report an error in Bugzilla  4. Layer Groups 4. Layer Groups Chapter 8. Combining Images  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. Layer Groups
This possibility appeared with GIMP-2.8 .
You can group layers that have similarities in a tree-like way. So, the
layer list becomes easier to manage.
Create a Layer Group
You can create a layer group by clicking on the
Create a new layer group
button at the bottom of the layer dialog ,
through
Layer → New Layer Group ,
or through the layer dialog context menu.
This empty layer group appears just above the current layer. It is
important to give it an evocative name (double-click or
F2 on the name, or use Edit Layer
Attributes in the context menu you get by right clicking the
Layer dialog, to edit it), else you will get confused when several
ones are created.
You can create several layer groups and you can
embbed them, that is include a
layer group in another one.
Adding Layers to a Layer Group
You can add existing layers to a layer group
by click-and-dragging them.
Note
The hand representing the mouse pointer must turn smaller
before releasing the mouse button.
A thin horizontal line marks where the layer will be laid
down.
To add a new layer to the current layer
group,
click on the Create a new layer at the
bottom of the layer dialog, or use the
New Layer command in the image menu.
When a layer group is not empty, a small “ & gt; ” icon
appears. By clicking on it, you can fold/unfold the layer list.
You can put layers to be added together to a layer group by making
them, them only, visible, and using the “ New From Visible
” command. All visible layers, outside and inside layer
groups, will be added to the active layer group.
Layers that belong to a layer group are slightly indented to the
right, allowing you know easily which layers are part of the
group.
Raise and Lower Layer Groups
You can raise and lower layer groups in the layer dialog as you do
with normal layers: click-and-dragging, using arrow up and down
keys at the bottom of the layer dialog .
Duplicate a Layer Group
You can duplicate a layer group: click on the
Create a duplicate of the layer button or
right-click and select the Duplicate Layer
command in the pop up context menu.
Move Layer Groups
You can move a layer group to another image
by click-and-dragging.
You can also copy-paste it using Ctrl-C and Ctrl-V: then, you get
a floating selection that you must anchor (anchor button at the
bottom of the layer dialog ).
You can also move a layer group to the
canvas : this duplicates the group in
the group. Chain all layers in the duplicated layer group, activate
the Move tool, then, in the image, move the layer. That's a way to
multiply multi-layer objects in an image.
Delete a Layer Group
To delete a layer group, click on the red cross button at the
bottom of the layer dialog or right-click and select
Delete layer .
Embed Layer Groups
When a layer group is activated, you can add another group inside
it with the “ Add New Layer Group ” command. There
seems to be no limit, excepted memory, to the number of embedded
layer groups.
Layer Modes and Groups
A layer mode applied to a layer group acts on layers that are in this
group only. A layer mode above a layer group acts on all layers
underneath,
outside and inside the layer groups.
Original image
Figure 8.33. Layer Mode in or out Layer Group
We added a white layer in the layer group
with saturation mode: only square and triangle are grayed out.
We added a white layer out of the layer
group with saturation mode: all layers underneath are grayed
out, background layer also.
Opacity
When a layer group is activated, opacity changes are applied to all
the layers of the group.
Layer Mask
You cannot add a layer mask to a layer group (the corresponding
option is grayed out). But, as with normal layers, you can add a layer
mask to a layer in the group to mask a part of the layer.
We added a white (Full opacity) layer mask to the triangle layer.
3. Creating New Layers Chapter 9. Text Management
 Report an error in Bugzilla 
8. 3. Invert 8. 3. Invert 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 3. Invert
The Invert command inverts all the pixel
colors and brightness values in the current layer, as if the image were
converted into a negative. Dark areas become bright and bright areas
become dark. Hues are replaced by their complementary colors. For more
information about colors, see the Glossary entry about
Color Model .
Note
This command only works on layers of RGB and Grayscale images. If the
current image is Indexed, the menu entry is insensitive and grayed out.
Warning
Do not confuse this command with the
Invert Selection command.
 8. 3. 1. Activate the Command
You can access this command from the image menubar through
Colors → Invert .  8. 3.2. Example Figure 16.121. Applying “ Invert colors ” Original image After the colors were inverted 8.2. Colors Tools 8. 4. Value Invert
 Report an error in Bugzilla  7. 19. Layer to Bottom 7.19. Layer to Bottom 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 19. Layer to Bottom
The Layer to bottom command lowers the active
layer to the bottom of the layer stack. If the active layer is already at the bottom of the stack or if there is only one layer , this menu
entry is insensitive and grayed out.
 7. 19. 1. Activating the Command
You can access this command from the image menubar through
Layer → Stack → Layer to Bottom ,
or by pressing the Shift key and clicking on the
down- arrow icon at the bottom of the Layers dialog.  7. 18. Layer to Top 7. 20. The “ Reverse Layer Order ” command  Report an error in Bugzilla  7. 17. Lower Layer 7. 17. Lower Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 17. Lower Layer
The Lower layer command lowers the active
layer one position in the layer stack. If the active layer is already at
the bottom of the stack or if there is only one layer , this menu entry
is insensitive and grayed out.
 7. 17. 1. Activating the Command
You can access this command from the image menubar through
Layer → Stack → Lower Layer ,
or by clicking on the down- arrow icon at the bottom of the Layers
dialog.  7. 16. Raise Layer 7. 18. Layer to Top
 Report an error in Bugzilla 
7. 22. Add Layer Mask 7. 22. Add Layer Mask 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 22. Add Layer Mask
The Add Layer Mask command adds a layer mask
to the active layer. It displays a dialog in which you can set the
initial properties of the mask. If the layer already has a layer mask,
the menu entry is insensitive and grayed out.
A layer mask lets you define which parts of the layer are opaque,
semi-transparent or transparent.
See the Layer Mask
section for more information.
 7. 22. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Add Layer Mask  or from the pop-up menu you get by right-clicking on the active layer in the Layers Dialog.
7. 22. 2. Description of the “ Add Layer Mask ” Dialog Figure 16.95. The “ Add Layer Mask ” dialog Initialize Layer Mask to
This dialog allows you several choices for the initial contents of
the layer mask:
White (full opacity)
With this option, the layer mask will make all of the
layer fully opaque. That means that you will not
notice any difference in the appearance of the layer
until you paint on the layer mask.
Black (full transparency)
With this option, the layer mask will make all of the
layer fully transparent. This is represented in the image
by a checkered pattern on which you will need to paint
to make any part of the layer visible.
Layer's alpha channel
With this option, the contents of the alpha channel
are used to fill the layer mask. The alpha channel
itself is not altered, so the transparency of
partially visible areas is increased, leading to
a more transparent layer.
Transfer layer's alpha channel
This option sets the layer mask as the previous
option, but resets the layer's alpha channel to full
opacity afterwards. The effect is to transfer the
transparency information from the alpha channel to the
layer mask, leaving the layer with the same appearance
as before. The visibility of the layer is now
determined by the layer mask alone and not by the
alpha channel. If in doubt, select this option instead
of “ Layer's alpha channel ” , because it will
leave the appearance unaltered.
Selection
This option converts the current selection into a layer
mask, so that selected areas are opaque, and unselected
areas are transparent. If any areas are partially
selected, you can click on the
QuickMask
button to help you predict what the effects will be.
Grayscale copy of layer
This option converts the layer itself into a layer mask.
It is particularly useful when you plan to add new
contents to the layer afterwards.
Channel
With this option the layer mask is initialized with a
selection mask you have created before, stored in the
Channel dialog.
Invert Mask
If you check the Invert Mask box at the
bottom of the dialog , the resulting mask is inverted, so that
transparent areas become opaque and vice versa.
When you click on the OK button , a thumbnail
of the layer mask appears to the right of the thumbnail of the layer
in the Layers Dialog.
7. 21. The “ Mask ” Submenu 7.23.
Apply Layer Mask  Report an error in Bugzilla  7. 23. Apply Layer Mask 7. 23.
Apply Layer Mask 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 23.
Apply Layer Mask
The Apply Layer Mask command merges the
layer mask with the current layer. The transparency information in the
layer mask is transferred to the alpha channel, that is created if it
doesn't exist, and the layer mask is removed. If the active layer does not
have a layer mask, the menu entry is insensitive and grayed out. See the
Layer Masks section for more
information .
 7. 23. 1.
Activating the Command
You can access this command from the image menubar through
Layer → Mask → Apply Layer Mask ,
or from the pop-up menu you get by right-clicking on the active
layer in the Layers Dialog.  7. 22. Add Layer Mask 7. 24. Delete Layer Mask
 Report an error in Bugzilla 
7. 24. Delete Layer Mask 7. 24. Delete Layer Mask 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 24. Delete Layer Mask
The Delete Layer Mask command deletes the
active layer's layer mask, without modifying the active layer itself. If
the active layer does not have a layer mask, the menu entry is
insensitive and grayed out.  7. 24. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Delete Layer Mask ,
or from the pop-up menu you get by right-clicking on the active
layer in the Layers Dialog.  7. 23.
Apply Layer Mask 7. 25. Show Layer Mask  Report an error in Bugzilla  7. 27. Disable Layer Mask 7.27. Disable Layer Mask 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 27. Disable Layer Mask As soon as you create a layer mask, it acts on the image. The
Disable Layer Mask command allows you to
suspend this action. When you click on the menu entry, a check is
displayed next to it and the border of the layer mask's thumbnail in
the Layers Dialog turns red.
 7. 27. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Disable Layer Mask ,
or by holding down the Ctrl key
( Ctrl + Alt
on some systems) and single-clicking on the layer mask's thumbnail
in the Layers Dialog.
You can undo this action by unchecking the menu entry in the
Layer → Mask
menu or by Ctrl - clicking (or
Ctrl + Alt
-clicking) again on the layer mask's thumbnail.  7. 26. Edit Layer Mask 7. 28. Mask to Selection
 Report an error in Bugzilla  7. 26. Edit Layer Mask 7. 26. Edit Layer Mask 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 26. Edit Layer Mask When you click on the Edit Layer Mask item on
the Layer Mask submenu, a check is displayed next to
it, the layer mask becomes the active component of the current layer and
the layer mask is displayed in the Layers Dialog with a white border.
When you uncheck it, the layer itself becomes the active component and
it is displayed with a white border. You can also activate the component
you want more simply by clicking on it in the Layers Dialog.
 7. 26. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Edit Layer Mask .  You can undo this action by unchecking the menu entry in the
Layer → Mask
menu or by clicking on the layer component in the Layers Dialog.
7. 25. Show Layer Mask 7.27. Disable Layer Mask  Report an error in Bugzilla 
7. 21. The “Mask” Submenu 7.21. The “ Mask ” Submenu 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 21. The “ Mask ” Submenu Figure 16.94.
The “ Mask ” submenu of the “ Layer ” menu
The Mask submenu of the Layer
menu contains commands which work with masks: creating a mask, applying
a mask, deleting a mask or converting a mask into a selection. See the
Layer Masks
section for more information on layer masks and how to use them .
7.21. 1. Activating the Submenu
You can access this submenu from the image menubar through
Layer → Mask
7.21. 2. The Contents of the “ Mask ” Submenu
The Mask submenu contains the following commands:
Section 7. 22, “Add Layer Mask” Section 7.23, “
Apply Layer Mask
” Section 7.24, “Delete Layer Mask” Section 7.25, “Show Layer Mask” Section 7.26, “Edit Layer Mask” Section 7.27, “Disable Layer Mask” Section 7.28, “Mask to Selection” Section 7.29, “Add Layer Mask to Selection” Section 7.30, “Subtract Layer Mask from Selection” Section 7.31, “Intersect Layer Mask with Selection” 7.20. The “ Reverse Layer Order ” command 7.22. Add Layer Mask
 Report an error in Bugzilla  7. 29. Add Layer Mask to Selection 7.29. Add Layer Mask to Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 29. Add Layer Mask to Selection
The Add to Selection command converts the
layer mask of the active layer into a selection , which is added to the
selection that is already active in the image. White areas of
the layer mask are selected, black areas are not selected, and gray
areas are converted into feathered selections. The layer mask itself is
not modified by this command.
 7. 29. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Add to Selection ,  7. 29.2. Illustration of Add Layer Mask to Selection Figure 16.97. Illustration of Add Layer Mask to Selection
On the left, the original image with a selection. In the middle,
the Layers Dialog with a layer mask created with the
“ Layer's alpha channel ” option. On the right, the
result after applying “ Mask to Selection ” : the
selection of the non-transparent pixels of the active layer
is added to the initial selection.
7.28. Mask to Selection 7. 30. Subtract Layer Mask from Selection  Report an error in Bugzilla  7. 31. Intersect Layer Mask with Selection 7.31. Intersect Layer Mask with Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 31. Intersect Layer Mask with Selection
The Intersect with Selection command converts
the layer mask of the active layer into a selection . The intersection of
this selection and the selection that is already active form the new
selection for the image. White areas of the layer mask are selected,
black areas are not selected, and gray areas are converted into
feathered selections. The layer mask itself is not modified by this
command.
 7. 31. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Intersect with Selection ,  7. 31.2.
Illustration of Intersecting the Layer Mask with the Selection
Figure 16.99.
Illustration of Intersecting the Layer Mask with the Selection
On the left, the original image with a selection. In the middle,
the Layers Dialog with a layer mask created with the
“ Layer's alpha channel ” option. On the right, the
result after applying “ Intersect Mask with
Selection ” : the selection of the non-transparent pixels of
the active layer is the common part between the initial selection
and the mask.
7.30. Subtract Layer Mask from Selection 7. 32.
The “ Transparency ” Submenu of the “ Layer ” menu
 Report an error in Bugzilla  7. 28. Mask to Selection 7.28. Mask to Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 28. Mask to Selection
The Mask to Selection command converts the
layer mask of the active layer into a selection , which replaces the
selection that is already active in the image. White areas of the layer
mask are selected, black areas are not selected, and gray areas are
converted into feathered selections. The layer mask itself is not
modified by this command.
 7. 28. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Mask to Selection ,
or from the pop-up menu you get by right-clicking on the active
layer in the Layers Dialog.  7. 28.2. Illustration of “ Layer Mask to Selection ” Figure 16.96. Illustration of “ Layer Mask to Selection ”
On the left , the original image with a selection. In the middle,
the Layers Dialog with a layer mask created with the
“ Layer's alpha channel ” option. On the right, the
result after applying “ Mask to Selection ” : the
selection of the non-transparent pixels of the active layer
replaces the initial selection.
7.27. Disable Layer Mask 7. 29. Add Layer Mask to Selection  Report an error in Bugzilla 
7. 30. Subtract Layer Mask from Selection 7.30. Subtract Layer Mask from Selection 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 30. Subtract Layer Mask from Selection
The Subtract from Selection command converts
the layer mask of the active layer into a selection , which is subtracted
from the selection that is already active in the image. White areas of
the layer mask are selected, black areas are not selected, and gray
areas are converted into feathered selections. The layer mask itself is
not modified by this command.
 7. 30. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Subtract from Selection ,  7. 30.2. Illustration of Subtract Layer Mask from Selection Figure 16.98. Illustration of Subtract Layer Mask from Selection
On the left, the original image with a selection. In the middle,
the Layers Dialog with a layer mask created with the
“ Layer's alpha channel ” option. On the right, the
result after applying “ Mask to Selection ” : the
selection of the non-transparent pixels of the active layer
is subtracted from the initial selection.
7.29. Add Layer Mask to Selection 7.31. Intersect Layer Mask with Selection
 Report an error in Bugzilla 
7. 25. Show Layer Mask 7.25. Show Layer Mask 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 25. Show Layer Mask The Show Layer Mask command lets you see the
layer mask better by turning the image invisible. When you click on the
menu entry, a check is displayed next to it and the layer mask's
thumbnail in the Layers Dialog is shown with a green border. The layer
itself is not modified; you can turn it visible again later.
 7. 25. 1. Activating the Command
You can access this command from the image menubar through
Layer → Mask → Show Layer Mask ,
or by holding down the Alt key
( Ctrl + Alt
on some systems) and single-clicking on the layer mask's
thumbnail in the Layers Dialog.
You can undo this action by unchecking the menu entry in the
Layer → Mask
submenu or by Alt - clicking (or
Ctrl + Alt -clicking)
again on the layer mask's thumbnail.  7. 24. Delete Layer Mask 7. 26. Edit Layer Mask
 Report an error in Bugzilla 
7. The “Layer” Menu 7. The “ Layer ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. The “ Layer ” Menu 7. 1. Introduction to the “ Layer ” Menu Figure 16. 88. The Contents of the “ Layer ” Menu
The items on the Layer menu allow you to work on
layers.
In addition to accessing the Layer menu from
the Image menubar and by right-clicking on the image window, you can
get to it by right-clicking on the thumbnail of a layer in the Layers
dialog. You can also perform several of the operations on this menu by
clicking on buttons in the Layers dialog, for example, resizing a layer,
managing layer transparency and merging layers.
Figure 16.89. The Contents of the “ Layer ” local pop- menu Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
6.28. Image Properties 7.2. New Layer
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7. 7. Merge Down 7. 7. Merge Down 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 7. Merge Down
The Merge Down
command merges the active layer with the layer just below it in the stack,
taking into account the various properties of the active layer, such as
its opacity and layer
mode .
The resulting merged layer will be in Normal mode, and will inherit the
opacity of the layer below. If the layer below is not opaque, or if it is
in some mode other than Normal, then this command will generally change
the appearance of the image .
The most common use of Merge Down is to
construct a layer, by starting with a “ base layer ” (usually
opaque and in Normal mode, so that you can see what you are doing), and
adding a “ modification layer ” on top of it, with whatever
shape, opacity, and layer mode you need. In this case, merging down the
modification layer will combine the two layers into one, without
changing the way the image looks.
 7. 7. 1. Activating the Command
You can access this command from the image menubar through
Layer → Merge Down .  7. 6. Anchor layer 7. 8. Delete Layer  Report an error in Bugzilla  7. 4. New From Visible 7. 4. New From Visible 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 4. New From Visible
This command merges the visible layers into a new layer at the top of
the layer stack.
The aim is to further manipulate the result, but keep the steps that
created this situation. Example: You want to selectively blur some
areas of your multilayer image. You create a new layer from what you
see, blur it and then apply a layer mask to erase the parts you want
your original work to show.
 7. 4. 1. Activating the Command
You can access this command from the image menubar through
Layer → New From Visible .  7. 3. New Layer Group 7. 5. Duplicate layer
 Report an error in Bugzilla  7. 3. New Layer Group 7. 3. New Layer Group 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 3. New Layer Group This command creates a new layer group directly. Please refer to
Section 4, “Layer Groups” .
 7. 3. 1. Activating the Command
You can access this command from an image menu through
Layer → New Layer Group ,
or from the layer context menu you get by right clicking on the layer
dialog.  7. 2. New Layer 7. 4. New From Visible  Report an error in Bugzilla 
7. 2. New Layer 7. 2. New Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 2. New Layer
The New Layer command adds a new , empty
layer to the layer stack of the image, just above the active layer.
The command displays a dialog in which you can specify the size of
the new layer.
 7. 2. 1. Activating the Command
You can access this command from the image menubar through
Layer → New Layer .  7. 2. 2. Description of the “ New Layer ” Dialog Figure 16. 90. The “ New Layer ” dialog
Under the title “ Create a new layer ” you can see the name
of the image for that you create this new layer and next to the title
a thumbnail of it. That is interesting to see if you have selected the
good image when there is more than one image open.
Layer Name
The name of the new layer . It does not have any functional
significance; it is simply a convenient way for you to remember
the purpose of the layer. The default name is “ New
Layer ” . If a layer with the name you choose already
exists, a number is automatically appended to it to make it
unique (e.g., “ New Layer#1 ” ) when you click on the
OK button .
Width; Height
The dimensions of the new layer. When the dialog appears, the
values are initialized to the dimensions of the image. You can
change them by using the two text boxes. You can also change
the units in the pull-down menu to the right.
Layer Fill Type
There are four options for the solid color that fills the layer:
the current Foreground color ,
the current Background color ,
White and
Transparency .
7. The “ Layer ” Menu 7. 3. New Layer Group
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7. 13. Select Next Layer 7. 13. Select Next Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 13. Select Next Layer
The Select Next Layer command selects the
layer just underneath the active layer in the layer stack. The command
highlights the layer in the Layers Dialog and makes it the new active
layer. If the active layer is already at the bottom of the stack , this
menu entry is insensitive and grayed out.
Note
Note that on a standard Windows-style English keyboard, the
default shortcut Page_Down does
not refer to the key on the numeric keypad, but to the other
Page_Down key in the group of six keys to the
left of the numeric keypad.
 7. 13. 1. Activating the Command
You can access this command from the image menubar through
Layer → Stack → Select Next Layer ,
or by using the keyboard shortcut Down .
Or you simply click on the layer name in the Layers Dialog.  7. 12. Select Previous Layer 7. 14. Select Top Layer
 Report an error in Bugzilla  7. 49. Offset 7.49. Offset 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 49. Offset
The Offset command shifts the
content of the active layer . Anything shifted
outside the layer boundary is cropped. This command displays
a dialog which allows you to specify how much to shift the layer and
how to fill the space that is left empty by shifting it.
 7. 49. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transform → Offset ,
or by using the keyboard shortcut
Shift + Ctrl + O .  7. 49.2. Using the “ Offset ” Command Figure 16.114. The “ Offset ” dialog Offset X; Y
With these two values, you specify how far the contents of
the layer should be shifted in the horizontal (X) and
vertical (Y) directions . You can enter the offsets in the
text boxes. Positive values move the layer to the right
and downward. The default unit is pixels, but you can
choose a different unit of measurement with the drop-down
menu. A unit of “ % ” is sometimes useful.
Offset by x/2, y/2
With this button, you can automatically set the
X and Y offsets
so that the contents are shifted by exactly half the width
and half the height of the image .
Edge Behavior
You can specify one of three ways to treat the areas left empty
when the contents of the layer are shifted:
Wrap around :
The empty space on one side of the layer is filled with the
part of the layer which is shifted out of the other side, so
none of the content is lost.
Fill with background color :
The empty space is filled with the background color , which
is shown in the Color Area of the Toolbox .
Make transparent :
The empty space is made transparent. If the layer does not
have an alpha channel , this choice is not available (grayed
out).
7.49.3. Example Figure 16.115. Using “ Offset ” together with “ Edge Behaviors ”
The Original
Y = -40, wrap
Y = -40, bg color
X = 40, transparent
7.48. Arbitrary Rotation 7.50. Layer Boundary Size
 Report an error in Bugzilla  7. 12. Select Previous Layer 7. 12. Select Previous Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 12. Select Previous Layer
The Select Previous Layer command selects the
layer just above the active layer in the layer stack. The command
highlights the layer in the Layers Dialog and makes it the new active
layer. If the active layer is already at the top of the stack , this
menu entry is insensitive and grayed out.
Note
Note that on a standard Windows-style English keyboard, the default
shortcut Page_Up does not refer to the key on the
numeric keypad, but to the other Page_Up key in the
group of six keys to the left of the numeric keypad.
Tip
The keyboard shortcuts for
Select Previous Layer and
Select Next Layer may be very useful if
you frequently pick colors from one layer to use for painting on
another layer, especially when you use them with the color-picker
tool , which you get by holding down the Ctrl key
with most of the painting tools.
 7. 12. 1. Activating the Command
You can access this command from the image menubar through
Layer → Stack → Select Previous Layer ,
or by using the keyboard shortcut Up .  Or you simply click on the layer name in the Layers Dialog.
7. 11. “ Stack ” Submenu 7.13. Select Next Layer
 Report an error in Bugzilla  7. 18. Layer to Top 7. 18. Layer to Top 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 18. Layer to Top
The Layer to Top command raises the active
layer to the top of the layer stack. If the active layer is already at
the top or if there is only one layer , this menu entry is insensitive
and grayed out. If the active layer is at the bottom of the stack and it
does not have an alpha channel, you cannot raise it until you add an
alpha channel to it.
 7. 18. 1. Activating the Command
You can access this command from the image menubar through
Layer → Stack → Layer to Top ,
or by pressing the Shift key and clicking on the
up- arrow icon at the bottom of the Layers dialog.  7. 17. Lower Layer 7. 19. Layer to Bottom
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7. 16. Raise Layer 7. 16. Raise Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 16. Raise Layer
The Raise Layer command raises the active
layer one position in the layer stack. If the active layer is
already at the top or if there is only one layer , this menu entry is
insensitive and grayed out. If the active layer is at the bottom of the
stack and it does not have an alpha channel, it cannot be raised until
you add an alpha channel to it.
 7. 16. 1. Activating the Command
You can access this command from the image menubar through
Layer → Stack → Raise Layer ,
or by clicking on the up- arrow icon at the bottom of the Layers
dialog.  7. 15. Select Bottom Layer 7. 17. Lower Layer
 Report an error in Bugzilla  7. 51. Layer to Image Size 7.51. Layer to Image Size 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 51. Layer to Image Size The Layer to Image Size command resizes the
layer boundaries to match the image boundaries, without moving the
contents of the layer with respect to the image.
 7. 51. 1. Activating the Command
You can access this command from the image menubar through
Layer → Layer to Image Size .  7. 50. Layer Boundary Size 7. 52. Scale Layer
 Report an error in Bugzilla  7. 50. Layer Boundary Size 7. 50. Layer Boundary Size 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 50. Layer Boundary Size
In GIMP , a layer is not always the same size
as the image it belongs to. It might be smaller or it might be larger,
in which case some parts of it are hidden. The
Layer Boundary Size command displays a dialog
in which you can set the dimensions for the active layer. This command
changes the dimensions of the layer, but it does not
scale its contents.
 7. 50. 1. Activating the Command
You can access this command from the image menubar through
Layer → Layer Boundary Size .  7. 50. 2.
Description of the “ Layer Boundary Size ” dialog
Figure 16. 116. The “ Layer Boundary Size ” Dialog Layer Size Width; Height
When the dialog is displayed, the original dimensions of
the active layer are shown. You can change them by using
the two text boxes. If these boxes are linked together
with a chain, the width-to-height ratio is automatically
maintained. If you break the chain by clicking on it, you
can set the dimensions independently of each other.
The default unit of measurement is pixels . You can change
this by using the drop-down menu. For instance, you might
use a “ % ” of the current size.
X Offset; Y Offset
By default, the resized layer is placed in the upper left
corner of the image . Here, you can set the offset of the
upper left corner of the layer relative to the same corner
of the image. The default unit of measurement is pixels ,
but you can change it by using the drop-down menu. You can
also place the layer in the center of the image by
clicking on the Center button.
7.49. Offset 7.51. Layer to Image Size
 Report an error in Bugzilla  7. 47. Rotate 180° 7.47. Rotate 180° 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 47. Rotate 180°
The Rotate 180° command rotates the
active layer by 180° around the center of the layer , with no loss of
pixel data. The shape of the layer is not altered. Since the layers have
a rectangular shape, a 180° rotation only invert them and they can't
extend beyond the image limits.
 7. 47. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transform → Rotate 180° .  7. 47.2. Example Figure 16.112. Applying “ Rotate 180° ”
Before applying the command
The layer after it has been rotated . It is turned upside down.
7.46. Rotate 90° counter-clockwise 7.48. Arbitrary Rotation
 Report an error in Bugzilla  7. 46. Rotate 90° counter-clockwise 7.46. Rotate 90° counter- clockwise 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 46. Rotate 90° counter-clockwise
The Rotate 90° counter- clockwise command
rotates the active layer by 90° counter-clockwise around the center of the
layer , with no loss of pixel data. The shape of the layer is not altered,
but the rotation may cause the layer to extend beyond the bounds of the
image. This is allowed in GIMP and it does
not mean that the layer is cropped. However, you will not be able to see
the parts which extend beyond the boundary of the image unless you
resize the image canvas or move the layer.
 7. 46. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transform → Rotate 90° counter-clockwise .  7. 46.2. Example Figure 16.111. Applying “ Rotate 90° counter- clockwise ”
Before applying the command
The layer after it has been rotated
7. 45. Rotate 90° clockwise 7.47. Rotate 180°  Report an error in Bugzilla 
7. 45. Rotate 90° clockwise 7.45. Rotate 90° clockwise 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 45. Rotate 90° clockwise
The Rotate 90° clockwise command rotates the
active layer by 90° around the center of the layer , with no loss of
pixel data. The shape of the layer is not altered, but the rotation may
cause the layer to extend beyond the bounds of the image. This is
allowed in GIMP and it does not mean that
the layer is cropped. However, you will not be able to see the parts
which extend beyond the boundary of the image unless you
resize the image canvas or move the layer.
 7. 45. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transform → Rotate 90° clockwise .  7. 45.2. Example Figure 16.110. Applying “ Rotate 90° clockwise ”
Before applying the command
The layer after it has been rotated
7. 44. Flip Vertically 7.46. Rotate 90° counter- clockwise
 Report an error in Bugzilla  7. 48. Arbitrary Rotation 7.48. Arbitrary Rotation 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 48. Arbitrary Rotation
The Arbitrary Rotation command rotates a
layer by a specified angle. It is an alternate way of accessing the
Rotate tool . See the section
about that tool for more information.
 7. 48. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transform → Arbitrary Rotation ,
or by using the keyboard shortcut
Shift + R .  7. 48.2. Example Figure 16.113. Applying “ Rotate Arbitrary ”
Before applying the command
The layer after it has been rotated 30° clockwise
7.47. Rotate 180° 7.49. Offset
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7. 52. Scale Layer 7.52. Scale Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 52. Scale Layer
The Scale Layer command resizes the layer
and its contents. The image loses some of its quality by being scaled.
The command displays a dialog where you can set parameters
concerning the size of the layer and the image quality.
 7. 52. 1. Activating the Command
You can access this command from the image menubar through
Layer → Scale Layer .  7. 52. 2. Description of the “ Scale Layer ” Dialog Figure 16. 117. The “ Scale Layer ” dialog Layer Size
When you enlarge a layer, GIMP has
to calculate new pixels from the existing ones. This procedure
is called “ interpolation ” . Please note that no
matter which interpolation algorithm is used, no new information
is added to the image by interpolation. If there are places in
the layer which have no details, you will not get any new ones
by scaling it. It is much more likely that the layer will look
somewhat blurred after scaling. Similarly, when you reduce a
layer, the image loses some of its quality when pixels are
removed.
Width; Height
The command displays a dialog which shows the dimensions
of the original layer in pixels. You can set the new
Width and
Height for the layer in the two text
boxes. If the adjacent chain icon is unbroken, the width
and height are automatically adjusted to hold their ratio
constant. If you break the chain by clicking on it, you
can set them separately, but this will result in
distorting the layer.
However, you do not have to set the dimensions in pixels.
You can choose different units from the drop-down menu. If
you choose percent as units, you can set the layer size
relative to its original size. You can also use physical
units, like inches or millimeters. However if you do that,
you should pay attention to the
X/Y resolution of the image.
If you enlarge a layer, the missing pixels are calculated
by interpolation, but no new details are added. The more
the layer is enlarged, and the more times it is enlarged,
the more blurred it becomes. The exact result of the
enlargement depends upon the interpolation method you
choose. After scaling, you can improve the result by using
the Sharpen filter ,
but it is much better for you to use a high resolution
when scanning, taking digital photographs or producing
digital images by other means. It is an inherent
characteristic of raster images that they do not scale up
well.
Quality
To change the size of the layer , GIMP
either has to add or remove pixels. The method it uses to do
this has a considerable impact on the quality of the result . You
can choose the method of interpolating the colors of the pixels
from the Interpolation drop-down menu.
Interpolation None
No interpolation is used. Pixels are simply enlarged
or removed, as they are when zooming. This method is
low in quality, but very fast.
Linear
This method is a good compromise between speed and
quality.
Cubic
This method takes a lot of time , but it produces the
best results.
Sinc (Lanczos3)
The Lanczos (pronounce “ lanzosh ” ) method
uses the
Sinc [12]
mathematical function to perform a high quality
interpolation.
[12] Sinus cardinalis 7.51. Layer to Image Size 7.53. Crop to Selection
 Report an error in Bugzilla  7. 11. “Stack” Submenu 7.11. “ Stack ” Submenu 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 11. “ Stack ” Submenu Figure 16.93. The “ Stack ” submenu
The layer stack is simply the list of layers in the Layers dialog .
The Stack submenu contains operations which either
select a new layer as the active layer, or change the position of the
active layer in the layer stack. If your image has only one layer, these
commands are grayed out.
 7. 11. 1. Activating the Submenu
You can access this submenu from the image menubar through
Layer → Stack .  7. 11. 2. The Contents of the “ Stack ” Submenu
The Stack submenu contains the following
commands:
Section 7. 12, “Select Previous Layer” Section 7.13, “Select Next Layer” Section 7.14, “Select Top Layer” Section 7.15, “Select Bottom Layer” Section 7.16, “Raise Layer” Section 7.17, “Lower Layer” Section 7.18, “Layer to Top” Section 7.19, “Layer to Bottom” Section 7.20, “The “ Reverse Layer Order ” command” 7.10. Discard Text Information 7.12. Select Previous Layer
 Report an error in Bugzilla  7. 9. The Text Commands of the Layer Menu 7. 9. The Text Commands of the Layer Menu 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 9. The Text Commands of the Layer Menu
These commands are displayed only if a text layer is present.
Figure 16. 91. Text commands in the Layer menu 7.9. 1. The Text Commands Section 7.10, “Discard Text Information” ??? ???
In the Text to Selection drop-down list, the
commands are identical to those of the Transparency sub-menu
(in fact, the text is formed of areas of different transparency):
Text to Selection: Section 7.38, “Alpha to Selection” Add to Selection: Section 7.39, “Add Alpha channel to Selection” Subtract from Selection: Section 7.40, “Subtract from Selection” Intersect with Selection: Section 7.41, “Intersect Alpha channel with Selection” 7. 8. Delete Layer 7.10. Discard Text Information
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7. 10. Discard Text Information 7.10. Discard Text Information 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 10. Discard Text Information
This command belongs to a group of Text commands displayed only if a
text layer is present.
Figure 16. 92.
The Discard Text command among text commands in the Layer menu
When you add text to an image, GIMP adds specific
informations. This command lets you discard these informations,
transforming the current text layer into a normal bitmap layer. The
reason to do that is not evident.
Note that this transformation of text into bitmap is automatically
performed when you apply a graphic operation to the text layer. You can
get text information back by undoing the operation which modified the
text.
 7. 10. 1. Activating the Command
You can access this command from the image menubar through
Layer → Discard Text Information .  7. 9. The Text Commands of the Layer Menu 7. 11. “ Stack ” Submenu
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7. 14. Select Top Layer 7. 14. Select Top Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 14. Select Top Layer
The Select Top Layer command makes the top
layer in the stack the active layer for the image and highlights it in
the Layers dialog. If the active layer is already the top layer in the
stack , this menu entry is insensitive and grayed out.
Note
Note that on a standard Windows-style English keyboard, the default
keyboard shortcut Home does not refer to the key on
the numeric keypad, but to the other Home key in
the group of six keys to the left of the numeric keypad.
 7. 14. 1. Activating the Command
You can access this command from the image menubar through
Layer → Stack → Select Top Layer ,
or by using the keyboard shortcut Home .
Or you simply click on the layer name in the Layers Dialog.  7. 13. Select Next Layer 7. 15. Select Bottom Layer
 Report an error in Bugzilla  7. 42. The “Transform” Submenu 7.42. The “ Transform ” Submenu 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 42. The “ Transform ” Submenu Figure 16.107.
The “ Transform ” Submenu of the “ Layer ” menu
The Transform submenu of the
Layer menu contains commands which flip or rotate
the active layer of the image .
 7. 42. 1. Activating the Submenu
You can access this submenu from the image menubar through
Layer → Transform .  7. 42. 2. The Contents of the “ Transform ” Submenu
The Transform submenu contains the following
commands:
Section 7. 43, “Flip Horizontally” Section 7.44, “Flip Vertically” Section 7.45, “Rotate 90° clockwise” Section 7.46, “Rotate 90° counter-clockwise” Section 7.47, “Rotate 180°” Section 7.48, “Arbitrary Rotation” Section 7.49, “Offset” 7.41. Intersect Alpha channel with Selection 7.43. Flip Horizontally
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7. 32. The “Transparency” Submenu of the “Layer” menu 7.32.
The “ Transparency ” Submenu of the “ Layer ” menu
7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 32.
The “ Transparency ” Submenu of the “ Layer ” menu
Figure 16. 100.
The “ Transparency ” submenu of the “ Layer ” menu
The Transparency submenu contains commands
which use or affect the alpha channel of the active layer .
7.32. 1. Activating the Submenu
You can access this submenu from the image menu bar through Layer → Transparency .
7.32. 2. The Contents of the “ Transparency ” Submenu
The Transparency submenu contains the
following commands:
Section 7. 33, “Add Alpha Channel” Section 7.34, “Remove Alpha Channel” Section 7.35, “Color to Alpha” Section 7.36, “Semi-flatten” Section 7.37, “Threshold Alpha” Section 7.38, “Alpha to Selection” Section 7.39, “Add Alpha channel to Selection” Section 7.40, “Subtract from Selection” Section 7.41, “Intersect Alpha channel with Selection” 7. 31. Intersect Layer Mask with Selection 7.33. Add Alpha Channel
 Report an error in Bugzilla  8. 8. White Balance 8.8. White Balance 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 8. 1. Activate the Command
You can access this command from the image menubar through
Colors → Auto → White Balance .  8. 8.2. “ White Balance ” example Figure 16. 134. Original image
The active layer and its Red, Green and Blue histograms
before “ White Balance ” .
Figure 16.135. Image after the command
The active layer and its Red, Green and Blue histograms after
“ White Balance ” . Poor white areas in the image
became pure white.
Histogram stretching creates gaps between the pixel columns,
giving it a striped look.
8. 7. Equalize 8.9. Color Enhance
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3. 21. Modules 3.21. Modules 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 21. Modules
With the Modules command, you can show
the various extension modules which are available and control which
of them should be loaded. Modules perform functions such as choosing
colors and display filtering. Any changes you make to the settings with
the Module Manager command will take effect the next time you start
GIMP . These changes affect
GIMP 's functional capabilities, its size in
memory and its start-up time.
 3. 21. 1. Activating the Command
You can access this command from the image menubar through
Edit → Modules  3. 21. 2. Description of the “ Module Manager ” Dialog Figure 16.22. The “ Module Manager ” dialog window
The window of the Module Manager shows the loadable modules.
Clicking on the boxes in the first column of the modules list will check
or uncheck the modules. The next time you start GIMP ,
any checked module will be loaded.
You will notice the difference only when you try to use the modules.
For example, there are several color
selectors to select the foreground or background color . Some of
these selectors are modules and will only be available when you check
the respective option in the module manager:
Figure 16.23. Loaded modules example: Color selector modules Color selector modules loaded Color selector modules not loaded
For loaded modules, information about the selected module is displayed
at the bottom of the dialog .
In the second column, for each loaded module the purpose of the module
is shown. For any module, that is not loaded, the directory path of this
module is shown.
When you click on the Refresh button , the list of
modules will be updated: modules no longer on disk will be removed, and
new modules found will be added.
3.20. Keyboard Shortcuts 3.22. Units
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2. 6. Navigation Dialog 2.6. Navigation Dialog 2. Image Structure Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 6. Navigation Dialog Figure 15.21. Navigation Dialog
The Navigation dialog is designed to offer easy movement around the active
image if the zoom is set higher than what the image window can display. If
this is the case, there is an inversely colored rectangle that shows the
location of the current view area in respect to the image.
To change the viewing region:
Click and drag the rectangular area.
Use Shift and mouse-wheel to move horizontally,
Alt and mouse-wheel to move vertically. The mouse
pointer must be on the rectangular area in the shape of a grabbing
hand.
 2. 6. 1. Activating the dialog
The “ Navigation ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking”
for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Navigation ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Navigation ,
from the image-menu:
View → Navigation window . 
You can access more quickly to it (but without the zoom functions)
by clicking on the icon at the right bottom corner of the image window:
2.6.2. Using the Navigation Dialog The slider
It allows easy zoom level control, more precise than with the
Zoom command. This slider can
also be moved using the mouse wheel when the mouse pointer is on
the slider, or Ctrl and mouse wheel when the mouse
pointer is on the rectangular area.
The buttons Zoom Out Zoom In
and Zoom 1:1
are self explanatory.
Adjust the zoom ratio so that the image becomes fully visible
The zoom ratio is adjusted so that the whole image becomes
visible in the window as it is.
Adjust the zoom ratio so that the window is used optimally
The image size and the zoom are adjusted so that the image
is fully displayed with the lesser zoom.
Reduce the image window to the size of the image display
Restore the image window to the size which allows the image
to be fully displayed with the zoom unchanged. This command
is also as menu entry available. See
Section 5.5, “Shrink Wrap” for the details.
2.5. Histogram dialog 2.7. Undo History Dialog  Report an error in Bugzilla  Chapter 7. Painting with GIMP Chapter 7. Painting with GIMP Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 7. Painting with GIMP Table of Contents 1. The Selection 1.1. Feathering 1.2. Making a Selection Partially Transparent 2. Creating and Using Selections 2.1. Moving a Selection 2.2. Adding or subtracting selections 3. The QuickMask 3.1. Overview 3.2. Properties 4. Using QuickMask Mode 5.
Paths
5.1. Path Creation 5.2. Path Properties 5. 3. Paths and Selections 5.4. Transforming Paths 5. 5. Stroking a Path 5. 6. Paths and Text 5.7. Paths and SVG files 6. Brushes 7. Adding New Brushes 8. The GIH Dialog Box 9. Varying brush size 9.1. How to vary the height of a brush 9.2. Creating a brush quickly 10. Gradients 11. Patterns 12. Palettes 12.1. Colormap 13. Presets 14. Drawing Simple Objects 14. 1. Drawing a Straight Line 14.2. Creating a Basic Shape 1. The Selection
Often when you operate on an image, you only want part of it to be
affected. In GIMP , you make this happen by
selecting
that part. Each image has a selection
associated with it. Most, but not all, GIMP operations
act only on the selected portions of the image.
Figure 7.1. How would you isolate the tree?
There are many, many situations where creating just the right selection is
the key to getting the result you want, and often it is not easy to
do . For example, in the above image, suppose I want to cut the tree out
from its background, and paste it into a different image. To do
this, I need to create a selection that contains the tree and nothing but
the tree. It is difficult because the tree has a complex shape, and
in several spots is hard to distinguish from the objects behind it.
Figure 7.2. Selection shown as usual with dashed line.
Now here is a very important point, and it is crucial to understand this.
Ordinarily when you create a selection, you see it as a dashed line
enclosing a portion of the image . The common, not entirely accurate,
idea you could get from this, is that
the selection is a sort of container, with the selected parts of the image
inside, and the unselected parts outside. Although this concept of
selection is okay for many purposes, it is not entirely correct.
Actually the selection is implemented as a channel .
In terms of its internal structure, it is identical to the red, green,
blue, and alpha channels of an image. Thus, the selection has a value
defined at each pixel of the image, ranging between 0 (unselected) and 255
(fully selected). The advantage of this approach is that it allows some
pixels to be partially selected ,
by giving them intermediate values between 0 and 255. As you will see,
there are many situations where it is desirable to have smooth transitions
between selected and unselected regions.
What, then, is the dashed line that appears when you create a selection?
The dashed line is a contour line , dividing areas
that are more
than half selected from areas that are less than half selected.
Figure 7.3. Same selection in QuickMask mode .
While looking at the dashed line that represents the selection, always
remember that the line tells only part of the story. If you
want to see the selection in complete detail, the easiest way is to click
the QuickMask button in the lower left corner of the image window . This
causes the selection to be shown as a translucent overlay atop the image.
Selected areas are unaffected; unselected areas are reddened. The more
completely selected an area is, the less red it appears.
Many operations work differently in QuickMask mode, as mentioned in the
QuickMask overview .
Use the QuickMask button in the lower left corner of the image window to
toggle QuickMask mode on and off.
Figure 7.4. Same selection in QuickMask mode after feathering. 1.1. Feathering
With the default settings, the basic selection tools, such as the
Rectangle Select tool, create sharp selections. Pixels inside the dashed
line are fully selected, and pixels outside completely unselected. You
can verify this by toggling QuickMask: you see a clear rectangle with
sharp edges, surrounded by uniform red.
Use the “ Feather edges ” checkbox in the Tool Options to
toggle between graduated selections and sharp selections.
The feather radius, which
you can adjust, determines the distance over which the transition
occurs.
If you are following along, try this with the Rectangle Select tool ,
and then toggle QuickMask. You will see that the clear rectangle has
a fuzzy edge.
Feathering is particularly useful when you are cutting and pasting, so
that the pasted object blends smoothly and unobtrusively with its
surroundings.
It is possible to feather a selection at any time, even if it
was originally created as a sharp selection. Use
Select → Feather
from the image menu to open the Feather Selection dialog. Set the
feather radius and click OK . Use
Select → Sharpen
to do the opposite—sharpen a graduated selection into an
all-or-nothing selection.
Note
For technically oriented readers: feathering works by applying a
Gaussian blur to the selection channel, with the specified blurring
radius.
1.2. Making a Selection Partially Transparent
You can set layer opacity, but you cannot do that directly for a
selection. It is quite useful to make the image of a glass
transparent. Use the following methods to set the layer opacity:
For simple selections, use the Eraser tool with the desired opacity.
For complex selections: use
Selection → Floating
to create a floating selection. This creates a new layer with
the selection called “ Floating Selection ” .
Set the opacity slider in the Layer Dialog to the desired opacity.
Then anchor the selection: outside the selection, the mouse pointer
includes an anchor. When you click while the mouse pointer includes
the anchor, the floating selection
disappears from the Layer Dialog and the selection is at the right
place and partially transparent (anchoring works this way only if a
selection tool is activated : you can also use the Anchor Layer
command in the context menu by right clicking on the selected layer
in the layer dialog).
And, if you use this function frequently:
Ctrl - C to copy the selection,
Ctrl - V to paste the clipboard as a floating selection, and
Layer → New Layer to turn the selection into a new layer.
You can adjust the opacity before, or after creating the new layer.
Another way: use
Layer → Mask → Add Layer Mask
to add a layer mask to the layer with the
selection, initializing it with the selection. Then use a brush with
the desired opacity to paint the selection with black, i.e. paint it
with transparency. Then Layer/Mask/Apply Layer Mask. See
Section 2.1.3, “Layer masks” .
To make the solid background of an image
transparent , add an Alpha channel, and use the Magic
Wand to select the background. Then, use the Color Picker
tool to select the background color, which becomes the foreground
color in Toolbox. Use the Bucket Fill tool with the selected color.
Set the Bucket Fill mode to “ Color Erase ” , which erases
pixels with the selected color; other pixels are partially erased
and their color is changed.
The simplest method is to use
Edit → Clear , which gives complete transparency to a selection.
2.3. Saving Images with Transparency 2. Creating and Using Selections  Report an error in Bugzilla  3. 5. Palettes Dialog 3.5. Palettes Dialog 3. Image-content Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 5. Palettes Dialog A palette is a set of discrete colors, in no
particular order. See the
Palettes section for basic
information on palettes and how they can be created and used.
The “ Palettes ” dialog is used to select a palette, by
clicking on it in a list or grid view . A few dozen more or less randomly
chosen palettes are supplied with GIMP, and you can easily add new
palettes of your own. The “ Palettes ” dialog also give you
access to several operations for creating new palettes or manipulating
the ones that already exist.
Note
The “ Palettes ” dialog is not the same thing as the
Index Palette
dialog ,
which is used to manipulate the colormaps of indexed images.
 3. 5. 1. Activating the dialog
The “ Palettes ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking” for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Palettes ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Palettes . 
3.5.2. Using the Palettes dialog
Clicking on a palette in the dialog selects this palette and brings up
the Palette Editor ,
which allows you to set GIMP's foreground or background colors by
clicking on colors in the palette display. You can also use the
arrow keys to select a palette.
Double-clicking on a palette name
(in List View mode) lets you to edit the name. Note that you are only
allowed to change the names of palettes that you have added yourself,
not those that are supplied with GIMP . If you edit a name that you are
not allowed to change , it will revert back to its previous value as soon
as you hit return or move the pointer focus elsewhere.
Grid/List modes Figure 15.50. The “ Palettes ” dialog Grid View List View
In the Tab menu , you can choose between
View as Grid
and View as List .
In Grid mode, the palettes are laid out in a spectacular
rectangular array, making it easy to see many at once and find
the one you are looking for. In List mode (the default), the
palettes are lined up in a list, with the names beside them.
The option Preview Size allows you to adapt
the size of color cell previews to your liking.
Tagging
You can use tags to reorganize the palettes display.
See Section 3.6, “Tagging” .
The buttons of the Palettes Dialog
Below the palettes view, at the bottom of the dialog window, there are
several buttons:
Edit Palette
This button brings up the
Section 3.5.4, “Palette Editor” .
New Palette
For more information on this button please refer to
New Palette .
Duplicate Palette
For more information on this button please refer to
Duplicate Palette .
Delete Palette
For more information on this button please refer to
Delete Palette .
Refresh Palettes
For more information on this button please refer to
Refresh Palettes .
3.5.3. The “ Palettes ” pop-menu Figure 15.51. The “ Palettes ” pop-menu The “ Palettes ” pop- menu can be accessed by right-clicking in the Palettes dialog, or by choosing the top item from the dialog Tab
menu
( ).
Note
Some of the listed pop-menu entries are installation dependend
and need the Python language
interpreter to be installed. This includes at the
time of writing: Offset
Palette... , Palette to gradient ,
Palette to
Repeating Gradient and Sort Palette... .
Edit Palette “ Edit Palette ” is an alternative way of activating
the
Palette Editor :
it can also be activated by double-clicking on a palette in the
Palettes dialog , or by pressing the “ Edit Palette ”
button at the bottom of the dialog .
New Palette “ New Palette ” creates a new, untitled palette,
initially containing no color entries, and pops up the Palette
Editor so that you can add colors to the palette. The result
will automatically be saved in your personal
palettes folder when you quit GIMP, so it
will be available from the Palettes dialog in future sessions.
Import Palette Figure 15.52. The Import Palette dialog “ Import Palette ”
allows you to create a new palette from the colors in a gradient ,
an image or a palette file. Choosing it brings up the
“ Import Palette ” dialog, which gives you the
following options:
Note
Former versions of GIMP had a “ Save palette ”
command. It no longer exists. To save the palette of an image,
indexed or not, you must import it in fact
from the image.
Select Source
You can import a palette either from any of GIMP's
gradients (choosing one from the adjoining menu), or from
any of the currently open images (chosen from the adjoining
menu). Since GIMP 2.2, you can also import a RIFF palette
file (with extension .pal ), of the
type used by several Microsoft Windows applications.
Two options concerning image as source, available for RGB
images only:
Sample merged : When this option
is checked , colors are picked from all visible
layers. If unchecked, pixels are picked from the
active layer only, even though not visible.
Selected pixels only : As the
name says, pixels are picked from the selected area
only, in the active layer or all visible layers
according to the status of the previous option.
Palette name
You can give a name to the new palette here. If the name
you choose is already used by an existing palette, a unique
name will be formed by appending a number (e. g., "#1").
Number of colors
Here you specify the number of colors in the palette. The
default is 256, chosen for three reasons: (1) every
gradient contains 256 distinct colors; (2) GIF files can
use a maximum of 256 colors; (3) GIMP indexed images can
contain a maximum of 256 distinct colors. You can use any
number you like here, though: GIMP will try to create a
palette by spacing the specified number of colors even
across the color range of the gradient or image.
Columns
Here you specify the number of columns for the palette.
This only affects the way the palette is displayed, and has
no effect on the way the palette is used.
Interval
Even setting “ Number of colors ” to maximum, the
number of colors can't exceed 10000 in the palette. RGB
images have much more colors. Interval
should allow to group similar colors around an average and
so get a better palette. This problem doesn't exist with 256
colors indexed images: Interval to 1 allows picking 256
colors (this option is grayed out with more than 256 colors
indexed palettes too).
The imported palette will be added to the Palettes dialog, and
automatically saved in your personal
palettes folder when you
quit GIMP , so it will be available in future
sessions.
Duplicate Palette
Duplicate Palette creates a new palette by copying the palette
that is currently selected, and brings up a Palette Editor so that
you can alter the palette. The result will automatically be saved
in your personal palettes
folder when you quit GIMP, so it will be available from the
Palettes dialog in future sessions.
Merge Palettes
Currently this operation is not implemented, and the menu entry
will always be insensitive.
Copy Palette Location
This command allows you to copy the palette file location to
clipboard. You can then paste it in a text editor.
Delete Palette
Delete Palette removes the palette from the “ Palettes
” dialog , and deletes the disk file in which it is stored.
Before it acts, it asks you confirm that you really want to do
these things. Note that you cannot remove any of the palettes
that are supplied with GIMP , only palettes you have added
yourself.
Refresh Palettes
Refresh Palettes rescans all of the folders in your palette
search path, and adds any newly discovered palettes to the list
in the Palettes dialog. This may be useful if you obtain palette
files from some external source, copy them into one of your
palettes folders, and want to make them available during the
current session.
Offset Palette... This command opens a dialog window : Figure 15.53. The “ Offset Palette ” dialog
This command takes the last color of the palette and puts it at
the first place. The Offset parameter lets
you set how many times this action must be performed.
With negative “ Offsets ” colors are put from the first
position to the end of the colors list.
Figure 15.54. “ Offset Palette ” examples
From top to bottom: original palette, Offset = 1, Offset =
2.
Palette to gradient
With this command, all the colors of the palette are used to form
the current gradient which is saved in the Gradient Dialog. The
created gradient is build with segments just as much as the number
of colors on the given palette.
Palette to Repeating Gradient
This command creates a repeating gradient, using all the colors
of the palette . This gradient appears in the Gradient Dialog and
becomes the current gradient. The gradient is created with
segments one more than the number of colors on the given palette.
The left side color at the leftmost segment will be the same color
on the right side at the rightmost segment.
Figure 15.55.
“ Palette to repeating gradient ” examples
Top: palette. Bottom: the gradient created with the
command.
Sort Palette...
This command opens a dialog window which allows you to sort the
colors of the palette according to certain criterions:
Figure 15.56. The “ Sort Palette ” dialog Color model : you can choose between
RGB and HSV
Channel to sort : you can choose between
the three RGB channels if the RGB model is selected, or the
three HSV channels if the HSV channel is selected.
Ascending (default is Yes): values are
sorted from the lower to the upper. By clicking on this
Yes you can toggle to
No and values will be sorted in
descending order.
3.5.4. Palette Editor Figure 15.57. The Palette Editor
The Palette Editor is used mainly for two purposes: first, for setting
GIMP's foreground or background colors (as shown in the Color Area of
the Toolbox ) to selected colors from the palette; second, for modifying
the palette. You can activate the Palette Editor for any palette in the
Palettes dialog , but you can only modify palettes that you have created
yourself , not the palettes that are supplied when you install GIMP.
(You can, however, duplicate any palette and then edit the newly
created copy.) If you modify a palette, the results of your work will
automatically be saved when you exit from GIMP.
3.5.4. 1. How to Activate the Palette Editor
The Palette Editor is only accessible from the Palettes dialog: you
can activate it by double-clicking on a palette , or by pressing the
“ Edit Palette ” button at the bottom , or by choosing
“ Edit Palette ” from the “ Palettes ” Menu.
The Palette Editor is a dockable dialog; see the section on
Dialogs and Docking
for help on manipulating it.
3.5.4.2. Using the Palette Editor
If you click on a color box in the palette display, GIMP's foreground
color will be set to the selected color : you can see this in the
Color Area of the Toolbox . If you hold down the Ctrl
key while clicking, GIMP's background color will be set to the
selected color .
If the palette is a custom palette, double-clicking on a color not
only sets the foreground, it also brings up a color editor that
allows you to modify the selected palette entry.
Right-clicking in the palette display area brings up the Palette
Editor menu. It's functions are mainly the same as those of the
buttons at the bottom of the dialog .
Below the palette display area, at the left, appears a text entry
area that shows the name of the selected color (or “ Untitled
” if it does not have one). This information has no functional
significance, and is present only to serve you as a memory aid.
To the right of the name entry is a spinbutton that allows you to set
the number of columns used to display the palette. This only affects
the display, not how the palette works. If the value is set to 0, a
default will be used.
At the bottom of the dialog are a set of buttons, which mostly match
the entries in the Palette Editor menu, accessible by right-clicking
in the palette display area . Here are the buttons:
Save
This button causes the palette to be saved in your personal palettes folder. It
would be saved automatically when GIMP exits
in any case, but you might want to use this button if you are
concerned that GIMP might crash in the
meantime.
Revert
This operation has not yet been implemented.
Edit Color
Pops up a color editor allowing you to alter the color. If
the palette is one you aren't allowed to alter, this button
will be insensitive. See
below
New Color from FG
For more information on this button please refer to
below .
Delete Color
For more information on this button please refer to
below .
Zoom Out
For more information on this button please refer to
below .
Zoom In
For more information on this button please refer to
below .
Zoom All
For more information on this button please refer to
below .
3.5.5. The Palette Editor pop-menu Figure 15.58. The Palette Editor pop-menu
The Palette Editor Menu can be accessed by right-clicking on the
palette display in the Palette Editor, or by choosing the top entry from the dialog Tab menu . The operations in it can also be executed
using the buttons at the bottom of the Palette Editor dialog.
Edit Color “ Edit Color ” brings up a color editor that allows
you to modify the color of the selected palette entry. If
the palette is one that you are not allowed to edit (that is, one
supplied by GIMP when it is installed ), then the menu entry will
beinsensitive.
New Color from FG; New Color from BG
These commands each create a new palette entry, using either
GIMP's current foreground color (as shown in the Color Area of
the Toolbox ) , or the current background color.
Delete Color “ Delete Color ” removes the selected color entry
from the palette.
If the palette is one that you are not allowed to edit , then the
menu entry will be insensitive.
Zoom Out “ Zoom Out ” reduces the vertical scale of the
entries in the palette display.
Zoom In “ Zoom In ” increases the vertical scale of the
entries in the palette display.
Zoom All “ Zoom All ” adjusts the vertical size of the entries
in the palette display so that the entire palette fits into the
display area.
Edit Active Palette
When this option is checked (default), you can edit another
palette by clicking on it in the “ Palettes ” dialog .
3.4. Gradients Dialog 3. 6. Tagging
 Report an error in Bugzilla 
2. 3. Paths Dialog 2.3. Paths Dialog 2. Image Structure Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 3. Paths Dialog
Please see Section 5, “
Paths
” if you don't know what a
path is.
Figure 15.12. The “ Paths ” dialog
The “ Paths ” dialog is used to manage paths, allowing you to
create or delete them, save them, convert them to and from selections, etc.
 2. 3. 1. Activating the dialog
The “ Paths ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking”
for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Paths .
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Paths , 
In the Windows menu, there is a list of
detached windows which exists
only if at least one dialog remains open. In this case, you can raise
the “ Paths ” dialog from the image-menu:
Windows → Paths .
2.3.2. Using the Paths dialog
Each path belongs to one image: paths are components of images just
like layers. The Paths dialog shows you a list of all paths belonging
to the currently active image: switching images causes the dialog to
show a different list of paths. If the Paths dialog is embedded in a
“ Layers, Channels, and Paths ” dock, you can see the name
of the active image in the Image Menu at the top of the dock .
(Otherwise, you can add an Image Menu to the dock by choosing
“ Show Image Menu ” from the Tab menu.)
If you are familiar with the Layers dialog, you have a head start,
because the Paths dialog is in several ways similar. It shows a list of
all paths that exist in the image, with four items for each path:
Path visibility
An “ open eye ” icon if the path is visible, or a
blank space if it is not. “ Visible ” means that a
trace of the path is drawn on the image display. The path is not
actually shown in the image pixel data unless it has been stroked
or otherwise rendered. Clicking in the eye-symbol-space
toggles the visibility of the path.
Chain paths
A “ chain ” symbol is shown to the right of the
eye-symbol-space if the path is transform-locked, or a blank
space if it is not. “ Transform-locked ” means that
it forms
part of a set of elements (layers, channels, etc) that are
all affected in the same way by transformations (scaling,
rotation, etc) applied to any one of them. Clicking in the
chain-symbol-space toggles the transform-lock status of the
path.
Preview image
A small preview-icon showing a sketch of the path. If you click
on the icon and drag it into an image, this will create a copy of
the path in that image.
Path Name
The name of the path , which must be unique within the image.
Double-clicking on the name will allow you to edit it. If the
name you create already exists, a number will be appended (e.g.,
“ #1 ” ) to make it unique.
If the list is non-empty, at any given moment one of the members is the
image's active path ,
which will be the subject of any operations you perform using the
dialog menu or the buttons at the bottom : the active path is shown
highlighted in the list. Clicking on any of the entries will make it
the active path.
Right-clicking on any entry in the list brings up the
Paths Menu .
You can also access the Paths Menu from the dialog Tab menu .
2.3.3. Buttons
The buttons at the bottom of the Paths dialog all correspond to entries
in the Paths menu ( accessed by right-clicking on a path list entry),
but some of them have extra options obtainable by holding down modifier
keys while you press the button.
New Path
See New Path . Holding down
the Shift key brings up a dialog that allows you
to assign a name to the new (empty) path.
Raise Path
See Raise Path .
Lower Path
See Lower Path .
Duplicate Path
See Duplicate Path .
Path to Selection
Converts the path into a selection; see
Path to Selection
for a full explanation. You can use modifier keys to set the way
the new selection interacts with the existing selection:
Modifiers Action None Replace existing selection Shift Add to selection Ctrl Subtract from selection Shift + Ctrl Intersect with selection. Selection to Path
Holding down the Shift key brings up the
Advanced Options dialog, which
probably is only useful to GIMP developers.
Paint along the path
See Stroke Path .
Delete Path Delete Path deletes the current selected
path.
2.3.4. The “ Paths ” context menu Figure 15. 13. The “ Paths ” context menu
The Paths menu can be brought up by right-clicking on a path entry in
the list in the Paths dialog , or by choosing the top entry ("Paths
Menu") from the Paths dialog Tab menu. This menu gives you access to
most of the operations that affect paths.
Path Tool Path Tool is an alternative way to
activate the Path tool ,
used for creating and manipulating paths. It can also be
activated from the Toolbox, or by using the keyboard shortcut
B (for Bézier ).
Edit Path Attributes Edit Path Attributes brings up a small
dialog that allows you to change the name of the path . You
can also do this by double-clicking on the name in the list in
the Paths dialog .
New Path New Path creates a new path , adds it to
the list in the Paths dialog, and makes it the active path
for the image . It brings up a dialog that allows you to give a name to the path. The new path is created with no
anchor points, so you will need to use the Path tool to give
it some before you can use it for anything.
Raise Path Raise Path moves the path one slot higher
in the list in the Paths dialog . The position of a path in
the list has no functional significance, so this is simply a
convenience to help you keep things organized.
Lower Path Lower Path moves the path one slot lower
in the list in the Paths dialog . The position of a path in
the list has no functional significance, so this is simply a
convenience to help you keep things organized.
Duplicate Path “ Duplicate Path ” creates a copy of the active path,
assigns it a unique name, adds it to the list in the Paths dialog,
and makes it the active path for the image . The copy will
be visible only if the original path was visible.
Delete Path Delete Path deletes the current selected
path.
Merge Visible Paths Merge Visible Paths takes all the paths
in the image that are visible (that is, all that show
“ open eye ” symbols in the Paths dialog), and turns
them into components of a single path. This may be convenient if
you want to stroke them all in the same way, etc.
Path to Selection; Add to Selection; Subtract from Selection;
Intersect with Selection
These commands all convert the active path into a selection, and
then combine it with the existing selection in the specified
ways.
( “ Path to Selection ” discards the existing selection
and replaces it with one formed from the path.) If necessary, any
unclosed components of the path are closed by connecting the last
anchor point to the first anchor point with a straight line. The
“ marching ants ” for the resulting selection should
closely follow the path, but don't expect the correspondence to
be perfect.
Selection to Path
This operation can be accessed in several ways:
From an image menubar, as
Select → To Path
From the Paths dialog menu, as
Selection to Path .
From the Selection to Path button at the bottom of the Paths dialog .
Selection to Path creates a new path
from the image's selection. In most cases the resulting path
will closely follow the “ marching ants ” of the
selection, but the correspondence will not usually be perfect.
Converting a two-dimensional selection mask into a
one-dimensional path involves some rather tricky algorithms:
you can alter the way it is done using the
Advanced Options , which are accessed by
holding down the Shift key while pressing
the Selection to Path button at the bottom of the Paths dialog . This brings up the Advanced
Options dialog, which allows you to set 20 different options
and variables, all with cryptic names. The Advanced Options
are really intended for developers only, and help with them
goes beyond the scope of this documentation . Generally
speaking, Selection to Path will do
what you expect it to, and you don't need to worry about how
it is done (unless you want to).
Stroke Path
This operation can be accessed in several ways:
From an image menubar, as
Edit → Stroke Path
From the Paths dialog menu, as Stroke
Path .
From the Paint along the path button
at the bottom of the Paths dialog .
From the Stroke Path button in the
Tool Options for the Path tool.
“ Stroke Path ” renders the active path on the active
layer of the image , permitting a wide variety of line styles and
stroking options. See the section on
Stroking for more
information.
Copy Path Copy Path copies the active path to the
Paths Clipboard, enabling you to paste it into a different image.
Tip
You can also copy and paste a path by dragging its icon
from the Paths dialog into the target image's display.
Note
When you copy a path to an image , it is not visible. You have
to make it visible in the Path dialog.
Paste Path Paste Path creates a new path from the
contents of the Path Clipboard, adds it to the list in the
Paths dialog, and makes it the active path for the image . If
no path has previously been copied into the clipboard, the
menu entry will be insensitive.
Import Path Import Path creates a new path from an SVG
file : it pops up a file chooser dialog that allows you to navigate
to the file . See the Paths
section for information on SVG files and how they relate
to GIMP paths.
Export Path Export Path allows you to save a path to
a file: it pops up a file save dialog that allows you to
specify the file name and location. You can later add this
path to any GIMP image using the Import
Path command. The format used for saving paths is
SVG: this means that vector-graphics programs such as
Sodipodi or
Inkscape will also be able to
import the paths you save. See the
Paths section for more
information on SVG files and how they relate to GIMP paths.
2.2. Channels Dialog 2.4. Colormap Dialog  Report an error in Bugzilla 
4. 7. From Path 4. 7. From Path 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 7. From Path
The From Path command transforms the current
path into a selection. If the path is not closed, the command connects
the two end points with a straight line. The original path is unchanged.
 4. 7. 1. Activating the Command
You can access this command from the image menubar through
Select → From
Path .
In addition, you can click on the
Path to Selection button
in the Path dialog to access the command.
You can also use the keyboard shortcut
Shift + V .  4. 6. By Color 4. 8. Selection Editor
 Report an error in Bugzilla  3. 18. Stroke Path 3. 18. Stroke Path 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 18. Stroke Path
The Stroke Path command strokes a path in
the image. There are two ways you can stroke the path, either by using
a paint tool, or without using one. There are various options which you
can use to specify how this stroke should look.
Note
This command is active only if there is a path in your image.
 3. 18. 1. Activating the Command
You can access this command from the image menubar through
Edit → Stroke Path .
You can also access it by clicking on the button with the same name
in the Path dialog .  3. 18. 2. Description of the Dialog Window Figure 16. 20. The “ Choose Stroke Style ” dialog window
The Choose Stroke Style dialog box allows you to
choose between stroking the path with the options you specify or
stroking it with a paint tool. If you stroke the path with a paint
tool, the current paint tool options are used to draw the stroke.
Stroke line
The stroke is drawn with the current foreground color ,
set in the Toolbox. By clicking on the triangle next to
Line Style however, the dialog expands
and you can set several additional options:
Line Width
You can set the width of the stroke using the text box.
The default unit is pixels, but you can choose another
unit with the drop-down list button .
Solid color / Pattern
You can choose whether the line is drawn in the
Solid or the
Pattern
style. Here, Solid and Pattern are distinct from the dash
pattern. If you select a Solid line with no dash pattern, an
unbroken line is drawn in the foreground color set in the
Toolbox. If you select a Patterned line with no dash
pattern, an unbroken line is drawn with the pattern set in
the Toolbox. If you select a line with a dash pattern, the
color or pattern is still determined by the foreground color
or pattern set in the Toolbox. That is, if you select a
marbled pattern and Patterned, dashed lines, the dashes are
drawn in the marbled pattern
Line Style
This drop-list brings some detailed options :
Cap Style : You can choose the shape of
the ends of an unclosed path, which can be
Butt , Round
or Square .
Join Style :
You can choose the shape of the path corners by
clicking on Miter ,
Round or Bevel .
Miter limit :
When two segments of a path come together, the mitering of
the corner is determined by the Miter Limit. If the strokes
were wide, and no mitering were done, there would be pointed
ends sticking out at the corner. The Miter Limit setting
determines how the gap, formed when the outer edges of the
two lines are extended, will be filled. You can set it to a
value between 0.0 and 100.0, by using the slider or the
associated text box and its arrows.
Figure 16.21. Example of miter limit Left: Limit=0; Right: Limit=5; Dash Pattern :
On the pixel level, a dashed line is drawn as a series of
tiny boxes. You can modify the pattern of these boxes. The
black area with thin vertical lines represents the pixels of
the dash. If you click on a black pixel, you remove it from
the dash. If you click on a white pixel, you add it to the
dash. The gray areas indicate how the pattern will be
repeated when a dashed line is drawn .
Dash Preset :
Instead of making your own dash pattern, you can choose
one from the drop-down box. This pattern will
then be displayed in the Dash pattern
area, so you can get an idea of how it will look.
Anti-aliasing :
Curved strokes or strokes drawn at an angle may look jagged
or stair-stepped. The anti-aliasing option smooths them
out.
Stroking with a Paint Tool Paint Tool
You can select a paint tool to use to draw the stroke from
the drop-down box. If you do that, the currently-selected
options of the paint tool are used, rather than the settings
in the dialog.
Emulate Brush Dynamics
See Brush
Dynamics .
3.17. Stroke Selection 3.19. The “ Preferences ” Command
 Report an error in Bugzilla  3. 3. Patterns Dialog 3.3. Patterns Dialog 3. Image-content Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 3. Patterns Dialog
In GIMP , a pattern
is a small image used to fill areas by placing copies of side by side. See
the Patterns
section for basic information on patterns and how they can be created and
used.
You can use them with the
Bucket Fill
and Clone tools and the
Fill with pattern command .
The “ Patterns ” dialog is used to select a pattern, by
clicking on it in a list or grid view : the selected pattern will then be
shown in the Brush/Pattern/Gradient area of the Toolbox. A few dozen more
or less randomly chosen patterns are supplied with GIMP, and you can
easily add new patterns of your own.
 3. 3. 1. Activating the dialog
The “ Patterns ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking”
for help on manipulating it.
You can access it:
From the Toolbox, by clicking on the pattern symbol in the
Brush/Pattern/Gradient area.
from the image menu:
Windows → Dockable Dialogs → Patterns ;
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Patterns . 
From the Tool Options dialog of the
Clone tool and the
Bucket Fill tool , by
clicking on the pattern source button, you get a pop-up with
similar functionality that permits you to quickly choose a pattern
from the list; if you clic on the Bucket Fill button present on the
right bottom of the pop-up, you open the real pattern dialog. Note
that, depending on your Preferences, a pattern selected with the
pop-up may only apply to the currently active tool, not to other
paint tools. See the
Tool Option Preferences
section for more information.
3. 3.2. Using the pattern dialog Grid/List modes
In the Tab menu , you can choose between
View as Grid
and View as List .
In Grid mode, the patterns are laid out in a rectangular array ,
making it easy to see many at once and find the one you are
looking for. In List mode, the patterns are lined up in a list,
with the names beside them.
Tip
Independent of the real size of a pattern all patterns are shown
the same size in the dialog. So for larger patterns this means
that you see only a small portion of the pattern in the dialog
at all - no matter whether you view the dialog in the list or
the grid view. To see the full pattern you simply click on the
pattern and hold the mouse button
for a second.
Note
In the Tab menu, the option Preview Size
allows you to adapt the size of pattern previews to your liking.
Figure 15. 37. The Patterns dialog List view Grid mode Using the Patterns dialog ( Grid mode)
At the top appears the name of the currently selected
patterns, and its dimensions in pixels.
In the center appears a grid view of all available patterns,
with the currently selected one outlined. Clicking on one of
them sets it as GIMP's current pattern, and causes it to
appear in the Brush/Pattern/Gradient area of the Toolbox.
Using the Patterns dialog (List view )
In this view, instead of a grid, you see a list of patterns,
each labeled with its name and size. Clicking on a row in
the list sets that pattern as GIMP's current pattern, just
as it does in the grid view.
If you double-click
on the name of a pattern, you will be able to edit the name.
Note that you are only allowed to rename patterns that you
have added yourself, not the ones that are supplied with
GIMP . If you edit a name that you don't have permission to
change, as soon as you hit return or move to a different
control, the name will revert back to its previous value .
Everything else in the List view works the same way as it
does in the Grid view.
Delete Pattern
Pressing this button removes the pattern from the list and causes
the file representing it to be deleted from disk. Note that you
cannot remove any of the patterns that are supplied with GIMP and
installed in the system patterns
directory; you can only remove patterns that you have added to
folders where you have write permission.
Refresh Patterns
Pressing this button causes GIMP to rescan the
folders in your pattern search path, adding any newly discovered
patterns to the list. This button is useful if you add new
patterns to a folder, and want to make them available without
having to restart GIMP .
Open pattern as image
If you click on this button, the current pattern is opened in a
new image window. So, you can edit it. But if you try to save it
with the .pat , even with a
new name, you will bang into a “ Denied permission ”
problem because this image file is “ root ” . But this
is possible under Windows, less protected.
3.3. 3. Tagging
You can use tags to reorganize the patterns display.
See Section 3.6, “Tagging” .
3. 3.4. The Pattern context menu
You get it by right-clicking on the “ Patterns ”
dialog . The commands of this menu are described with Buttons,
except for Copy Location which allows to
copy the path to pattern into clipboard.
3.3.5. The Clipboard pattern
When you use the Copy or Cut command , a copy appears as a
new pattern in the upper left corner of the Patterns dialog.
This brush will persist until you use the Copy (or Cut) command again.
It will disappear when you close GIMP.
Figure 15. 38. A new “ Clipboard Pattern ” Note
You can save this clipboard pattern by using the
Edit → Paste as → New pattern
as soon as it appears in the Patterns dialog.
3. 2. Brushes Dialog 3.4. Gradients Dialog  Report an error in Bugzilla 
Chapter 12. Enrich my GIMP Chapter 12. Enrich my GIMP Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 12. Enrich my GIMP Table of Contents 1. Preferences Dialog 1.1. Introduction 1.2. Environment 1.3. Interface 1.4. Theme 1.5. Help System 1.6. Tool Options 1.7. Toolbox 1.8. Default Image Preferences 1.9. Default Image Grid 1.10. Image Windows 1.11. Image Window Appearance 1.12. Image Window Title and Statusbar 1.13. Display 1.14. Color Management 1.15. Input Devices 1.16. Input Controllers 1.17. Window Management 1.18. Folders 1.19. Data Folders 2. Grids and Guides 2.1. The Image Grid 2.2. Guides 3. Rendering a Grid 4. How to Set Your Tile Cache 5. Creating Shortcuts to Menu Functions 6. Customize Splash-Screen 1. Preferences Dialog 1.1. Introduction Figure 12.1. List of preference pages
The preferences dialog can be accessed from the image menu-bar , through
Edit → Preferences .
It lets you customize many aspects of the way
GIMP works. The following sections detail the settings that you
can customize, and what they affect.
All of the Preferences information is stored in a file called
gimprc in your personal GIMP directory , so
if you are a “ power user ” who would rather work with a
text editor than a graphical interface, you can alter preferences by
editing that file. If you do, and you are on a Linux system,
then man gimprc will give you a lot of
technical information about the contents of the file and what
they are used for.
1.2. Environment Figure 12.2. Environment Preferences
This page lets you customize the amount of system memory allocated
for various purposes. It also allows you to disable the confirmation
dialogs that appear when you close unsaved images, and to set the
size of thumbnail files that GIMP produces.
1.2.1. Options Resource Consumption Minimal number of undo levels
GIMP allows you to undo most actions by maintaining an
“ Undo History ”
for each image, for which a certain amount of memory is allocated.
Regardless of memory usage, however, GIMP always permits some
minimal number of the most recent actions to be undone: this is
the number specified here. See
Section 3, “Undoing”
for more information about GIMP's Undo mechanism.
Maximum undo memory
This is the amount of undo memory allocated for each image. If the
Undo History size exceeds this, the oldest points are deleted,
unless this would result in fewer points being present than the
minimal number specified above.
Tile cache size
This is the amount of system RAM allocated for GIMP image
data. If GIMP requires more memory than this, it begins to
swap to disk, which may in some circumstances cause a
dramatic slowdown. You are given an opportunity to set this
number when you install GIMP, but you can alter it here. See
How to Set Your
Tile Cache for more information.
Maximum new image size
This is not a hard constraint: if you try to create a new image
larger than the specified size, you are asked to confirm that you
really want to do it. This is to prevent you from accidentally
creating images much larger than you intend, which can either
crash GIMP or cause it to respond verrrrrrrry slowwwwwwwwly.
Number of processors to use
Default is one. Your computer may have more than one processor.
Image Thumbnails Size of thumbnails
This options allows you to set the size of the thumbnails shown
in the File Open dialog (and also saved for possible use by
other programs). The options are “ None ” ,
“ Normal (128x128) ” , and
“ Large (256x256) ” .
Maximum filesize for thumbnailing
If an image file is larger than the specified maximum size, GIMP
will not generate a thumbnail for it. This options allows you to
prevent thumbnailing of extremely large image files from slowing
GIMP to a crawl.
Saving Images Confirm closing of unsaved images Closing an image is not undoable , so by default GIMP asks you to
confirm that you really want to do it , whenever it would lead to
a loss of unsaved changes. You can disable this if you find it
annoying; but then of course you are responsible for remembering
what you have and have not saved.
Document history Keep record of used files in the Recent Documents list
When checked, files you have opened will be saved in the
Document history. You can access the list of files with the
Document history
dialog from the image menu-bar :
File → Open Recent → Document History .
1.3. Interface Figure 12.3. Assorted Interface Preferences
This page lets you customize language, layer/channel previews and
keyboard shortcuts.
Options Language
The GIMP's default language is that of your system. You can select
another language in the drop-down list . You have to start GIMP again
to make this change effective. Please refer to
Section 1.2, “Language” .
Previews
By default, GIMP shows miniature previews of the contents of
layers and channels in several places, including the Layers
dialog. If for some reason you would prefer to disable
these, you can do it by unchecking Enable layer and
channel previews . If you do want previews to be shown,
you can customize their sizes using the menus for Default
layer and channel preview size and Navigation
preview size .
Keyboard Shortcuts
Any menu item can be activated by holding down
Alt and pressing a sequence of keys.
Normally, the key associated with each menu entry is shown
as an underlined letter in the text, called
accelerator . If for some reason you
would prefer the underlines to go away (maybe because you
think they're ugly and you don't use them anyway), then you
can make this happen by unchecking Show menu
mnemonics .
GIMP can give you the ability to create keyboard shortcuts
(key combinations that activate a menu entry) dynamically,
by pressing the keys while the pointer hovers over the
desired menu entry. However, this capability is disabled by
default, because it might lead novice users to accidentally
overwrite the standard keyboard shortcuts. If you want to
enable it, check Use dynamics keyboard shortcuts
here.
Pressing the button for Configure Keyboard
Shortcuts brings up the Shortcut Editor, which gives you
a graphical interface to select menu items and assign shortcuts
to them.
If you change shortcuts, you will probably want your changes
to continue to apply in future GIMP sessions. If not,
uncheck Save keyboard shortcuts on exit . But
remember that you have done this, or you may be frustrated
later. If you don't want to save shortcuts on exit every
session, you can save the current settings at any time using the
Save Keyboard Shortcuts Now button, and they will
be applied to future sessions. If you decide that you have made
some bad decisions concerning shortcuts, you can reset them to
their original state by pressing Reset Saved Keyboard
Shortcuts to Default Values .
1.4. Theme Figure 12.4. Theme Preference
This page lets you select a theme, which determines many aspects of
the appearance of the GIMP user interface, including the set of
icons used, their sizes, fonts, spacing allowed in dialogs, etc.
Two themes are supplied with GIMP: Default ,
which is probably best for most people, and
Small , which may be preferable for those with
small or low-resolution monitors. Clicking on a theme in the list
causes it to be applied immediately, so it is easy to see the result
and change your mind if you don't like it.
You can also use custom themes, either by downloading them from the
net, or by copying one of the supplied themes and modifying it.
Custom themes should be places in the themes
subdirectory of your personal GIMP directory: if they are, they
will appear in the list here. Each theme is actually a directory
containing ASCII files that you can edit. They are pretty
complicated, and the meaning of the contents goes beyond the scope
of this documentation , but you should feel free to experiment: in
the worst case, if you mess things up completely, you can always
revert back to one of the supplied themes .
You cannot edit the supplied themes unless you have administrator
permissions, and even if you do, you shouldn't: if you want to
customize a theme, make a copy in your personal directory and work
on it. If you make a change and would like to see the result “ on
the fly ” , you can do so by saving the edited theme file and then
pressing Reload Current Theme .
1.5. Help System Figure 12.5. Help System Preferences
This page lets you customize the behaviour of the
GIMP help system.
1.5.1. Options General Show tool tips
Tool tips are small help pop-ups that appear when the pointer
hovers for a moment over some element of the interface, such as a
button or icon. Sometimes they explain what the element does;
sometimes they give you hints about non-obvious ways to use it.
If you find them too distracting, you can disable them here by
unchecking this option. We recommend that you leave them enabled
unless you are a very advanced user.
Show help buttons
This option controls whether the help buttons are shown
on every tool dialog, which may be used alternatively to
invoke the help system.
User manual
This drop-down list lets you select between
Use a locally installed copy and
Use the online version . See
Section 12.2, “Help” .
Help Browser Help browser to use
GIMP Help is supplied in the form of HTML files, i. e., web pages.
You can view them using either a special help browser that comes
with GIMP, or a web browser of your choice. Here you choose which
option to use. Because the help pages were carefully checked to
make sure they work well with GIMP's browser, whereas other web
browsers are somewhat variable in their support of features, the
safer option is to use the internal browser; but really any
modern web browser should be okay.
Note
Note that the GIMP help browser is not available on all
platforms. If it is missing, this option is hidden and the
standard web browser will be used to read the help pages.
1.6. Tool Options Figure 12.6. Tool Options Preferences
This page lets you customize several aspects of the behavior of
tools.
1.6.1. Options General Save Tool Options On Exit Self explanatory Save Tool Options Now Self explanatory Reset Saved Tool Options To Default Values Self explanatory Guide and Grid Snapping Snap distance “ Snapping ” to guides, or to an image grid, means
that when a tool is applied by clicking somewhere on the image
display, if the clicked point is near enough to a guide or grid ,
it is shifted exactly onto the guide or grid. Snapping to
guides can be toggled using
View → Snap to Guides in the image menu ; and if the grid is switched on, snapping
to it can be toggled using
View → Snap to Grid .
This preference option determines how close a
clicked point must be to a guide or grid in order to be
snapped onto it, in pixels.
Scaling Default interpolation
When you scale something, each pixel in the result is calculated
by interpolating
several pixels in the source. This option determines the default
interpolation method: it can always be changed, though, in the
Tool Options dialog.
There are four choices: None
This is the fastest method, but it's quite crude: you should
only consider using it if your machine is very seriously
speed-impaired.
Linear
This used to be the default, and is good enough for most
purposes.
Cubic
This is the best choice (although it can actually look worse
than Linear for some types of images), but also the slowest.
Since GIMP 2.6, this method is the
default.
Sinc (Lanczos3)
This method performs a high quality interpolation.
Paint Options Shared Between Tools Brush, Pattern, Gradient
You can decide here whether changing the brush etc for one tool
should cause the new item to be used for all tools, or whether
each individual tool (pencil, paintbrush, airbrush, etc) should
remember the item that was last used for it specifically.
Move tool Set layer or path as active
You can decide here whether changing the current layer or path
when using the move tool and without pressing any key.
1.7. Toolbox Figure 12.7. Toolbox Preferences 1.7.1. Options Figure 12.8. Default Toolbox appearance
This page lets you customize the appearance of the Toolbox, by deciding
whether the three “ context information ” areas should be
shown at the bottom.
Appearance Show foreground and background color
Controls whether the color area on the left (2) appears in the
Toolbox.
Show active brush, pattern, and gradient
Controls whether the area in the center (3), with the brush,
pattern, and gradient icons, appears in the
Toolbox.
Show active image
Controls whether a preview of the currently active image
appears on the right (4).
Tools configuration
In this list, tools with an eye are present in the Toolbox. By
default , color tools have no eye: you can add them to the Toolbox by
clicking the corresponding checkbox.
You can also sort tools by priority using the arrow up and down
buttons at the bottom of the dialog .
This option replaces the Tools Dialog of former
GIMP versions.
1.8. Default Image Preferences Figure 12.9. Default New Image Preferences
This tab lets you customize the default settings for the New Image
dialog. See the
New Image Dialog section
for an explanation of what each of the values means.
1.9. Default Image Grid Figure 12.10. Default Grid Preferences
This page lets you customize the default properties of GIMP's grid,
which can be toggled on or off using
View → Show Grid
from the image menu. The settings here match those in the
Configure Image Grid dialog, which can be used to reconfigure the
grid for an existing image, by choosing
Image → Configure Grid
from the image menu . See the
Configure Grid
dialog section for information on the meaning of each of
the settings.
1.10. Image Windows Figure 12.11. General Image Window Preference
This page lets you customize several aspects of the behaviour of
image windows.
1.10.1. Options General Use “ Dot for dot ” by default
Using “ Dot for dot ” means that at 1:1 zoom, each
pixel is the image is scaled to one pixel on the display. If
“ Dot for dot ” is not used, then the displayed image
size is determined by the X and Y resolution of the image. See the
Scale Image section for
more information.
Marching ants speed
When you create a selection, the edge of it is shown as a dashed
line with dashes that appear to move, marching slowly along the
boundary: they are jokingly called “ marching ants ” .
The smaller the value entered here, the faster the ants march
(and consequently the more distracting they are!).
Zoom and Resize Behavior Resize window on zoom
If this option is checked , then each time you zoom the image, the
image window will automatically resize to follow it. Otherwise,
the image window will maintain the same size when you zoom the
image.
Resize window on image size change If this option is checked , then each time change the size of the
image , by cropping or resizing it, the image window will
automatically resize to follow . Otherwise, the image window will
maintain the same size .
Initial zoom ratio
You can choose either to have images, when they are first opened,
scaled so that the whole image fits comfortably on your display,
or else shown at 1:1 zoom. If you choose the second option, and
the image is too large to fit on your display, then the image
window will show only part of it (but you will be able to scroll
to other parts).
Space bar While space bar is pressed Pan view (default) or Toogle to Move Tool No action Mouse Cursors Show brush outline
If this option is checked , then when you use a paint tool, the
outline of the brush will be shown on the image as you move the
pointer around. On slow systems, if the brush is very large, this
could occasionally cause some lag in GIMP's ability to follow your
movements: if so, switching this off might help. Otherwise, you
will probably find it quite useful.
Show paint tool cursor
If this is checked, a cursor will be shown. This is in addition to
the brush outline, if the brush outline is being shown. The type
of cursor is determined by the next option.
Cursor mode
This option has no effect unless Show paint tool
cursor is checked. If it is, you have three choices:
Tool icon , which causes a small iconic
representation of the currently active tool to be shown beside
the cursor; Tool icon with crosshair , which
shows the icon as well as a crosshair indicating the center of
the cursor; or Crosshair only .
Cursor rendering
If you choose “ Fancy ” here, the cursor is drawn in
grayscale. If you choose “ Black and White ” , it is
drawn in a simpler way that may speed things up a little bit if
you have speed issues.
1.11. Image Window Appearance Figure 12.12. Image Window Appearance Defaults
This page lets you customize the default appearance of image
windows, for normal mode and for fullscreen mode. All of the
settings here can be altered on an image-specific basis using
entries in the View menu. See the
Image Window
section for information on the meaning of the entries.
The only parts that may need further explanation are the ones related to
padding. “ Padding ”
is the color shown around the edges of the image, if it does not occupy
all of the display area (shown in light gray in all the figures here). You
can choose among four colors for the padding color: to use the color
specified by the current theme; to use the light or dark colors specified
for checks, such as represent transparent parts of the image ; or to use a
custom color, which can be set using the color button for
“ Custom padding color ” .
1.12. Image Window Title and Statusbar Figure 12.13. Image Window Title and Statusbar formats
This page lets you customize the text that appears in two
places: the title bar of an image, and the status bar. The
title bar should appear above the image; however this depends
on cooperation from the window manager, so it is not
guaranteed to work in all cases. The statusbar appears
underneath the image, on the right side. See the Image Window
section for more information.
1. 12.1. Choosing a Format
You can choose among several predesigned formats, or you can
create one of your own, by writing a format
string in the entry area. Here is how to understand
a format string: anything you type is shown exactly as you type
it, with the exception of variables , whose
names all begin with “ % ” . Here is a list of the variables
you can use:
Variable Meaning %f Bare filename of the image, or “ Untitled ” %F Full path to file, or “ Untitled ” %p Image id number (this is unique) %i
View number, if an image has more than one display
%t Image type (RGB, grayscale, indexed) %z Zoom factor as a percentage %s Source scale factor (zoom level = %d/%s) % d Destination scale factor (zoom level = %d/%s) % Dx
Expands to x if the image is dirty , nothing otherwise
%Cx
Expands to x if the image is clean, nothing otherwise
%l The number of layers %L Number of layers (long form) %m Memory used by the image %n Name of the active layer/channel %P id of the active layer/channel %w Image width in pixels %W Image width in real-world units %h Image height in pixels %H Image height in real-world units %u Unit symbol (eg. px for Pixel) %U Unit abbreviation %% A literal “ % ” symbol 1.13. Display Figure 12.14. Display Preferences
This page lets you customize the way transparent parts of an image
are represented, and lets you recalibrate the resolution of your
monitor.
1.13.1. Options Transparency Transparency type
By default, GIMP indicates transparency using a checkerboard
pattern with mid-tone checks, but you can change this if you want,
either to a different type of checkerboard, or to solid black,
white, or gray.
Check size
Here you can alter the size of the squares in the checkerboard
pattern used to indicate transparency.
Figure 12.15. The Calibration dialog Monitor Resolution
Monitor Resolution is the ratio of pixels, horizontally and
vertically, to inches. You have three ways to proceed here:
Get Resolution from windowing system. (easiest, probably
inaccurate).
Set Manually Push the Calibrate Button. The Calibrate Dialog
My monitor was impressively off when I tried the Calibrate Dialog.
The “ Calibrate Game ” is fun to play. You will need a
soft ruler.
1.14. Color Management Figure 12.16. Color Management Preferences 1.14.1. Options
This page lets you customize the GIMP color management.
Some of the options let you choose a color profile from a menu. If the
desired profile is not in the menu yet, you can add it by clicking on
the Select color profile from disk... item.
Tip
Files containing color profiles are easily recognizable by their
.icc suffix. In addition to that they are
usually stored all together in only a few places. If you are running
GIMP on Mac OS X, you should try
/Library/ColorSync/Profiles/ and
Library/Printers/[manufacturer]/Profiles .
Mode of operation
Using this option you can decide how the GIMP color management
operates. There are three modes you can choose from:
No color management : choosing this
selection shuts down the color management in GIMP completely.
Color managed display : with this
selection you can enable the GIMP color management to
provide a fully corrected display of the images according to
the given color profile for the display.
Print simulation : when choosing
this selection, you enable the GIMP color management not only
to apply the profile for the display, but also the selected
printer simulation profile. Doing so, you can preview the
color results of a print with that printer.
Note
Please note, that the GIMP color management is used to
enhance the display of images and the embedding of profiles
to image files only. Especially are the options you choose
in this dialog in no way used for printing from within GIMP.
This is because the printing is a special task done by a
more specialized printing engine that is no part of GIMP.
RGB profile
Select the default color profile for working with RGB images.
CMYK profile
Select the default color profile for conversion between RGB
for the screen work and CMYK for printing.
Monitor profile
This option gives you two elements for interaction:
You should select a display profile for this option. The
selected color profile is used to display GIMP on the screen.
If you activate the Try to use the system monitor
profile option, GIMP will use the color profile
provided for the displays by the operating systems color
management system.
Display rendering intent
Rendering intents, as the one you can configure with this option,
are ways of dealing with colors that are
out-of- Gamut colors
present in the source space that the destination space is
incapable of producing. There are four method rendering intents to
choose from:
Perceptual Relative colorimetric Saturation Absolute colorimetric
A description of the individual methods can be found at
Rendering Intent .
Print simulation mode
You should select a printer profile for this option. The selected
color profile is used for the print simulation mode.
Softproof rendering intent
This option again provides two different elements for interaction:
You can use the menu to select the rendering intent for the
soft proof. They are the same as already described for the
display rendering intent.
If you enable the Mark out of gamut
colors option, all pixels that have a color that
is not printable are marked by a special color. Which color is
used for this can also be chosen by you. You can do this
simply by clicking on the color icon on the right besides the
checkbox.
File Open behaviour
Using this menu you can determine how GIMP behaves when opening a
file that contains an embedded color profile that does not match
the workspace sRGB. You can choose from the following entries:
Ask what to do : if selected, GIMP
will ask every time what to do.
Keep embedded profile : if you
choose this, GIMP will keep the attached profile and not
convert the image to the workspace. The image is displayed
correctly anyways, because the attached profile will be
applied for display.
Convert to RGB workspace : by
choosing this entry GIMP will automatically use the attached
color profile to convert the image to the workspace.
Note For more explanations:
ICC Profiles are explained in Wikipedia
[ WKPD-ICC ] .
See OpenICC project
( [ OPENICC ] ) where GIMP and
others great names of free infography contribute to.
Many profiles to load from the web:
ICC sRGB Workspace:
ICCsRGB ™
[ ICCsRGB ]
Microsoft sRGB Workspace:
MsRGB ™
[ MsRGB ]
Adobe RGB98 Workspace :
Adobe RGB (1998) ™
[ AdobeRGB ]
ECI (European Color Initiative) Profiles :
ECI ™
[ ECI ]
1.15. Input Devices Figure 12.17. Input devices preferences Extended Input Devices Configure Extended Input Devices
This large button allows you to set the devices associated with your
computer: tablet, MIDI keyboard... If you have a tablet, you will
see a dialog like this:
Figure 12.18. Preferences for a tablet Save input device settings on exit When you check this box, GIMP remembers the tool, color, pattern and
brush you were using the last time you quitted.
Save Input Device Settings Now Self explanatory.
Reset Saved Input Device Settings to Default Values
Delete your settings and restore default settings.
1.16. Input Controllers Figure 12.19. Input controllers preferences
This dialog has two lists of additional input controllers:
Available Controllers on the left,
Active Controllers on the right.
A click on an item will highlight it and you can move the controller from
one list to the other by clicking on the respective arrow key. When you
try to move a controller from the list of active controllers to the
available controllers, a dialog pops up and you will have the choice of
removing the controller or just disabling it.
When you double click on a (typically active) controller or alternatively
click on the Edit button at the bottom of the list , you can configure this
controller in a dialog window:
Main Mouse Wheel
Figure 12.20. Main Mouse Wheel General Dump events from this controller
This option must be checked if you want a print on the stdout
of the events generated by the enabled controllers. If you
want to see those event you should start
GIMP from a terminal or making it to print
the stdout to file by the shell redirection. The main use of
this option is for debug.
Enable this controller
This option must be checked if you want to add a new actions
to the mouse wheel.
Mouse Wheel Events
In this window with scroll bars you have: on the left, the
possible events concerning the mouse wheel, more or less
associated with control keys; on the right, the action assigned
to the event when it will happen. You have also two buttons, one
to Edit the selected event, the other to
Cancel the action of the selected event.
Some actions are assigned to events yet. They seem to be examples,
as they are not functional.
Select the action allocated to the event
After selecting an event, if you click on the
Edit button , you open the following dialog:
Figure 12.21. Select Controller Event Action
If an action exists yet for this event, the window will open on this
action. Else, the window will display the sections that order
actions. Click on an action to select it.
Main Keyboard
You can use this dialog in the same way as that of the mouse wheel.
Events are related to the arrow keys of the keyboard , combined
or not with control keys.
Figure 12.22. Main Keyboard Note
You will find an example of these notions in
Creating a variable size brush
.
1.17. Window Management Figure 12.23. Window Management Preferences
This page lets you customize the way windows are handled in GIMP. You
should note that GIMP does not manipulate windows directly, instead it
sends requests to the window manager (i. e., to Windows if you are running
in Windows; to Metacity if you are running in a standard Gnome setup in
Linux; etc). Because there are many window managers, and not all of them
are well behaved, it cannot be guaranteed that the functions described
here will actually work as described. However, if you are using a modern,
standards-compliant window manager, they ought to.
1.17.1. Options Window Manager Hints Window type hints for the toolbox and the docks
The choices you make here determine how the Toolbox, and the docks
that hold dialogs, will be treated. You have three possibilities
for them:
If you choose Normal Window , they will
be treated like any other windows.
If you choose Utility Window , the
reduce button in the title bar is absent and the docks will
remain permanently on your screen.
Figure 12.24. Utility window title bar
Normal title bar
The title bar in a utility window
If you choose Keep above , they will be
kept in front of every other window at all times.
Note that changes you make here will not take effect until the
next time you start GIMP .
Focus Activate the focused image
Normally, when you focus an image window (usually indicated by a
change in the color of the frame), it becomes the “ active
image ” for GIMP, and therefore the target for any
image-related actions you perform. Some people, though, prefer
to set up their window managers such that any window entered by
the pointer is automatically focused. If you do this, you
may find that it is inconvenient for focused images to
automatically become active, and may be happier if you uncheck
this option.
Window Positions Save window positions on exit If this option is checked , the next time you start GIMP ,
you will see the same set of dialog windows, in the same
positions they occupied when you last exited.
Save Window Positions Now
This button is only useful if " Save window positions on exit " is
unchecked. It allows you to set up your windows they way you like,
click the button, and then have them come up in that arrangement
each time you start GIMP .
Reset Saved Window Positions to Default Values
If you decide that you are unhappy with the arrangement of windows
you have saved, and would rather go back to the default
arrangement than spend time moving them around, you can do so by
pressing this button.
1.18. Folders Figure 12.25. Basic Folder Preferences
This page allows you to set the locations for two important folders used
by GIMP for temporary files. The pages below it allow you to customize the
locations searched for resources such as brushes etc.; see
Data Folders
for a description that applies to them. You can change the folders here by
editing the entries, or by pressing the buttons on the right to bring up a
file chooser window.
Folders Temp folder
This folder is used for temporary files: files created for temporary
storage of working data, and then deleted within the same GIMP
session. It does not require a lot of space or high performance. By
default, a subdirectory called tmp
in your personal GIMP directory is used, but if that disk is very
cramped for space, or has serious performance issues, you can change
it to a different directory. The directory must exist and be
writable by you , or bad things will happen.
Swap folder
This is the folder used as a “ memory bank ” when the
total size of images and data open in GIMP exceeds the available
RAM. If you work
with very large images, or images with many layers, or have many
images open at once, GIMP can potentially require hundreds of
megabytes of swap space, so available disk space and performance are
definitely things to think about for this folder. By default, it is
set to your personal GIMP directory, but if you have another disk
with more free space, or substantially better performance, you may
see a significant benefit from moving your swap folder there. The
directory must exist and be writable by you .
1.19. Data Folders Figure 12.26. Preferences: Brush Folders
GIMP uses several types of resources – such as brushes, patterns,
gradients, etc. – for which a basic set are supplied by GIMP when it is
installed , and others can be created or downloaded by the user. For each
such resource type, there is a Preference page that allows you to specify
the search path :
the set of directories from which items of the type in question are
automatically loaded when GIMP starts. These pages all look very much the
same: the page for brushes is shown to the right as an example.
By default, the search path includes two folders : a
system folder, where items installed along
with GIMP are placed, and a personal folder,
inside your personal GIMP directory , where items added by you
should be placed. The system folder should not be marked as
writable, and you should not try to alter its contents. The
personal folder must be marked as writable or it is useless,
because there is nothing inside it except what you put there.
You can customize the search path with the buttons at the top of
the dialog .
Options Select a Folder
If you click on one of the folders in the list, it is selected for
whatever action comes next.
Add/Replace Folder
If you type the name of a folder in the entry space, or navigate to
it using the file chooser button
on the right, and then click the
left button, this will replace the selected folder with the one you
have specified. If nothing in the list is selected, the folder you
specify will be added to the list. If the light- symbol to the left
of the text entry area is red instead of green, it means that the
folder you have specified does not exist. GIMP will not create it
for you, so you should do this immediately.
Move Up/Down
If you click on the up-arrow or down-arrow buttons, the selected
folder will be changed to the following or preceding one in the
list. Since the folders are read in order, using those buttons
change the loading precedence of the items located in those folders.
Delete Folder
If you click the trash-can button, the selected folder will be
deleted from the list. (The folder itself is not affected; it is
merely removed from the search path.) Deleting the system folder is
probably a bad idea, but nothing prevents you from doing it.
Chapter 11. Color Management with GIMP 2. Grids and Guides
 Report an error in Bugzilla  5. 8. Pointer Dialog 5.8. Pointer Dialog 5. Misc. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 8. Pointer Dialog Figure 15.81. Pointer dialog
This dialog offers you, in a same window, in real time, the position of
the mouse pointer , and the channel values of the pointed pixel , in the
chosen color model.  5. 8. 1. Activating the dialog
The “ Pointer ” dialog is a dockable dialog; see the section Section 2.3, “Dialogs and Docking”
for help on manipulating it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Pointer .
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Pointer . 
5. 8.2. “ Pointer ” dialog options Pixels
Shows the position of the pointed pixel, in X (horizontal) and Y
(vertical) coordinates, stated in pixels from the origin ( the
upper left corner of the canvas ).
Units
Shows the distance from the origin, in inches.
Pointer Bounding Box
This information is active when a selection exists. X and Y are
the coordinates of the upper left corner of the rectangular frame
that bounds rectangular and ellipse selections. H and W are
the height and width of this box.
This information also exits for the other selections, but they are
of less interest and the bounding box is not visible.
This information concerning the selection remains unchanged when you
use another tool, while pointer coordinates vary.
Channel values
The channel values for the selected
color model are shown
below. Both pulldown menus contain the same choices, which
makes it easier for you to compare the color values of a
particular pixel using different color models.
“ Hex ” is the
HTML Notation of
the pixel color, in hexadecimal. The choices on the pulldown
menus are ( Pixel is the default):
Pixel
The RGB channel values.
This choice displays the Red ,
Green , Blue and
Alpha values of the pixel, as numbers
between 0 and 255.
RGB
The RGB channel values.
This choice displays the Red ,
Green , Blue and
Alpha values of the pixel, as
percentages. It also shows the hexadecimal value of the
pixel's color.
HSV
The HSV components.
This choice displays the Hue , in
degrees, as well as the Saturation ,
Value and Alpha of
the pixel, as percentages.
CMYK
The CMYK channel
values. This choice displays the Cyan ,
Magenta , Yellow ,
Black and Alpha
values of the pixel, as percentages.
Sample Merged
If this option is checked ( default), sampling is performed on all
layers. If it is unchecked, sampling is performed on the active
layer only .
5.7. Sample Points Dialog Chapter 16. Menus
 Report an error in Bugzilla 
4. 16. Toggle QuickMask 4. 16. Toggle QuickMask 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 16. Toggle QuickMask This command has the same action as clicking on the small button in the
bottom left corner of the image . See
Quick Mask
4.16. 1. Activate Dialog
You can access this command through
Select → Toggle QuickMask .
Default shortcut is
Shift + Q
4.15. Rounded Rectangle 4.17. Save to Channel  Report an error in Bugzilla 
5. 7. Sample Points Dialog 5.7. Sample Points Dialog 5. Misc. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 7. Sample Points Dialog
While the Color Picker
can display color information about one pixel, the
“ Sample Points ” dialog can display the data of four pixels of
the active layer or the image, at the same time. Another important
difference is that the values of these points are changed in real time
as you are working on the image.
 5. 7. 1. Activating the dialog
The “ Sample Points ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Sample Points .
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Sample Points  .
5. 7.2. Using sample points
To create a sample point, Ctrl - click on one of the
two measure rules of the image window and drag the mouse pointer .
Two perpendicular guides appear. The sample point is where both guides
intersect. You can see its coordinates in the lower left corner and
the information bar of the image window. Release the mouse button.
The reticle you get Ctrl + click-and-dragging from a rule.
By default, this sample point comes with a round mark and an order
number. You can cancel these marks by unchecking the Show
Sample Points option in the View
menu.
The “ Sample Points ” dialog should automatically open
when you create a sample point. This is not the case ; you have to
open it manually.
You can delete a sample point, as you do with guides, by
click-and-dragging it up to a rule. Order numbers are automatically
re-arranged in the dialog window; the most recent are moved one rank
up.
By default, sampling is performed on all layers. If you want to
sample on the active layer only , uncheck the Sample
merged option in the tab menu:
Figure 15. 79. The “ Sample Point ” menu 5.7.3. “ Sample Points ” dialog description Figure 15.80. Sample points dialog
The information about four sample points is displayed in this window.
You can create more, which will be existing and not shown. To show
them, you have to delete displayed points.
The color of the sampled point is displayed in a swatch box.
In the drop-down list , you can choose between:
Pixel
This choice displays the Red ,
Green , Blue and
Alpha values of the pixel, as numbers between
0 and 255.
RGB
This choice displays the Red ,
Green , Blue and
Alpha values of the pixel, as percentages. It
also shows the hexadecimal value of the pixel's color.
HSV
This choice displays the Hue , in degrees, as
well as the Saturation ,
Value and Alpha of the
pixel, as percentages.
CMYK
This choice displays the Cyan ,
Magenta , Yellow ,
Black and Alpha values
of the pixel, as percentages.
Data are supplied for every channel in the chosen color model. The
Alpha is present only if the image holds an Alpha channel .
Hexa appears only with the RGB mode. That's the
hexadecimal code of the
HTML Notation .
5.6. Export File 5.8. Pointer Dialog
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5. 5. Save File 5. 5. Save File 5. Misc. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 5. Save File
The Save command saves your image to disk. With
GIMP -2.8, this command saves in XCF format only. If you
try to save to a format other than XCF , you get an error message:
Starting from GIMP -2.8.8, the error dialog sports a
link that jumps directly to the export command dialog.
Please see Section 1.1, “Save / Export Images” .
If you have already saved the image, the previous image file is
overwritten with the current version. If you have not already saved the
image, the Save command opens the Save Image
dialog.
If you quit without having saved your image,
GIMP asks you if you really want to do so,
if the “ Confirm closing of unsaved images ” option is
checked in the Environment
page of the Preferences dialog.
Figure 15.77. Save Image Dialog 5.5.1. Activate the Dialog
You can access this command in the image menu bar through
File → Save ,
or from the keyboard by using the shortcut
Ctrl + S .
Use
Ctrl + Shift + S
to save the opened image with a different name.
5.5.2. The Save Image Dialog
With this file browser, you can edit filename directly in name box
(default is “ Untitled. xcf ” ) or by selecting a file in name
list.
We repeat that only XCF format is permitted. You must also fix the image
destination in Save in Folder . You can create a new
folder if necessary.
Select File Type.
If you develop this option, you can select a compressed format for your
XCF file :
5.4. Error Console 5. 6. Export File
 Report an error in Bugzilla  Chapter 13. Scripting Chapter 13. Scripting Part II.
How do I Become a GIMP Wizard?
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 13. Scripting Table of Contents 1. Plugins 1.1. Introduction 1.2. Using Plugins 1.3. Installing New Plugins 1.4. Writing Plugins 2. Using Script-Fu Scripts 2.1. Script-Fu? 2.2. Installing Script-Fus 2. 3. Do's and Don'ts 2.4. Different Kinds Of Script-Fus 2.5. Standalone Scripts 2.6. Image-Dependent Scripts 3. A Script-Fu Tutorial 3.1. Getting Acquainted With Scheme 3.2. Variables And Functions 3.3. Lists, Lists And More Lists 3.4. Your First Script-Fu Script 3. 5. Giving Our Script Some Guts 3.6. Extending The Text Box Script 3.7. Your script and its working 1. Plugins 1.1. Introduction
One of the nicest things about GIMP is how easily its
functionality can be extended, by using plugins.
GIMP plugins are external programs that run under the
control of the main GIMP application and interact
with it very closely. Plugins can manipulate images in almost any way
that users can. Their advantage is that it is much easier to add a
capability to GIMP by writing a small plugin than by
modifying the huge mass of complex code that makes up the
GIMP core. Many valuable plugins have C source code
that only comes to 100-200 lines or so.
Several dozen plugins are included in the main GIMP
distribution, and installed automatically along with
GIMP . Most of them can be accessed through the
Filters menu (in fact, everything in that menu is a
plugin), but a number are located in other menus. In many cases you can
use one without ever realizing that it is a plugin : for example, the
"Normalize" function for automatic color correction is actually a
plugin, although there is nothing about the way it works that would tell
you this.
In addition to the plugins included with GIMP , many
more are available on the net. A large number can be found at the
GIMP Plugin Registry
[ GIMP-REGISTRY ] ,
a web site whose purpose is to provide a central repository for
plugins. Creators of plugins can upload them there; users in search of
plugins for a specific purpose can search the site in a variety of ways .
Anybody in the world can write a GIMP plugin and make
it available over the web, either via the Registry or a personal web
site, and many very valuable plugins can be obtained in this way some
are described elsewhere in the User's Manual. With this freedom from
constraint comes a certain degree of risk, though: the fact that anybody
can do it means that there is no effective quality control. The plugins
distributed with GIMP have all been tested and tuned
by the developers, but many that you can download were just hacked
together in a few hours and then tossed to the winds. Some plugin
creators just don't care about robustness, and even for those who do,
their ability to test on a variety of systems in a variety of situations
is often quite limited. Basically, when you download a plugin, you are
getting something for free, and sometimes you get exactly what you pay
for. This is not said in an attempt to discourage you, just to make sure
you understand reality.
Warning
Plugins, being full-fledged executable programs, can do any of the
things that any other program can do, including install back-doors on
your system or otherwise compromise its security. Don't install a
plugin unless it comes from a trusted source.
These caveats apply as much to the Plugin Registry as to any other
source of plugins. The Registry is available to any plugin creator who
wants to use it: there is no systematic oversight. Obviously if the
maintainers became aware that something evil was there, they would
remove it. (That hasn't happened yet.) There is, however, for
GIMP and its plugins the same warranty as for any
other free software: namely, none.
Caution
Plugins have been a feature of GIMP for many
versions. However, plugins written for one version of
GIMP can hardly ever be used successfully with
other versions. They need to be ported: sometimes this is easy,
sometimes not. Many plugins are already available in several
versions. Bottom line: before trying to install a plugin, make sure
that it is written for your version of GIMP .
1.2. Using Plugins
For the most part you can use a plugin like any other
GIMP tool, without needing to be aware that it is a
plugin . But there are a few things about plugins that are useful to
understand.
One is that plugins are generally not as robust as the
GIMP core. When GIMP crashes, it
is considered a very serious thing: it can cost the user a lot of
trouble and headache. When a plugin crashes, the consequences are
usually not so serious. In most cases you can just continuing working
without worrying about it.
Note
Because plugins are separate programs, they communicate with the
GIMP core in a special way: The
GIMP developers call it “ talking over a
wire ” . When a plugin crashes, the communication breaks down,
and you will see an error message about a “ wire read
error ” .
Tip
When a plugin crashes, GIMP gives you a very
ominous-looking message telling you that the plugin may have left
GIMP in a corrupted state, and you should consider
saving your images and exiting. Strictly speaking, this is quite
correct, because plugins have the power to alter almost anything in
GIMP , but for practical purposes, experience has
shown that corruption is actually quite rare, and many users just
continue working and don't worry about it. Our advice is that you
simply think about how much trouble it would cause you if something
went wrong, and weigh it against the odds.
Because of the way plugins communicate with GIMP ,
they do not have any mechanism for being informed about changes you make
to an image after the plugin has been started. If you start a plugin,
and then alter the image using some other tool, the plugin will often
crash, and when it doesn't will usually give a bogus result. You should
avoid running more than one plugin at a time on an image, and avoid
doing anything to the image until the plugin has finished working on it.
If you ignore this advice, not only will you probably screw up the
image, you will probably screw up the undo system as well, so that you
won't even be able to recover from your foolishness.
1.3. Installing New Plugins
The plugins that are distributed with GIMP don't
require any special installation. Plugins that you download yourself do.
There are several scenarios, depending on what OS you are using and how
the plugin is structured. In Linux it is usually pretty easy to install
a new plugin; in Windows, it is either easy or very hard. In any case,
the two are best considered separately.
1.3.1. Linux / Unix-sytem like systems
Most plugins fall into two categories: small ones whose source
code is distributed as a single .c file, and larger ones whose
source code is distributed as a directory containing multiple
files including a Makefile .
For a simple one-file plugin, call it borker.c ,
installing it is just a matter of running the command
gimptool-2.0 --install borker.c . This command
compiles the plugin and installs it in your personal plugin directory ,
~/gimp-2.4/plugins unless you have changed it.
This will cause it to be loaded automatically the next time you start
GIMP . You don't need to be root to do these things;
in fact, you shouldn't be. If the plugin fails to compile, well, be
creative.
Once you have installed the plugin, how do you activate it? The menu
path is determined by the plugin itself, so to answer this you need to
either look at the documentation for the plugin (if there is any), or
launch the Plugin Description dialog (from Xtns/Plugins Details)
search the plug-in by its name and look of the
Tree view
tab. If you still don't find, finally explore the menus or look at the
source code in the Register section -- whichever is easiest.
For more complex plugins, organized as a directory with multiple
files, there ought to be a file inside called either
INSTALL or README , with
instructions. If not, the best advice is to toss the plugin in the
trash and spend your time on something else: any code written with so
little concern for the user is likely to be frustrating in myriad
ways.
Some plugins (specifically those based on the GIMP
Plugin Template) are designed to be installed in the main system
GIMP directory, rather than your home directory.
For these, you will need to be root to perform the final stage of
installation (when issuing the make install
command).
If you install in your personal plugin directory a plugin that has the
same name as one in the system plugin directory, only one can be
loaded, and it will be the one in your home directory. You will
receive messages telling you this each time you start
GIMP . This is probably a situation best avoided.
1.3.2. Windows
Windows is a much more problematic environment for building software
than Linux. Every decent Linux distribution comes fully supplied with
tools for compiling software, and they are all very similar in the way
they work, but Windows does not come with such tools. It is possible
to set up a good software-building environment in Windows, but it
requires either a substantial amount of money or a substantial amount
of effort and knowledge.
What this means in relation to GIMP plugins is the
following: either you have an environment in which you can build
software , or you don't. If you don't, then your best hope is to find a
precompiled version of the plugin somewhere (or persuade somebody to
compile it for you), in which case you simply need to put it into your
personal plugin directory. If you do have an environment in which you
can build software (which for present purposes means an environment in
which you can build GIMP ), then you no doubt
already know quite a bit about these things, and just need to follow
the Linux instructions.
1.3.3. Apple Mac OS X
How you install plugins on OS X mostly depends on how you installed
GIMP itself. If you were one of the brave and
installed GIMP
through one of the package managers like fink
[ DARWINORTS ] or darwinports,
[ FINK ] the
plugin installation works exactly the way it is described for the
Linux platform already. The only difference is, that a couple of
plugins might be even available in the repository of you package
manager, so give it a try.
If you on the other hand are one of the Users that preferred to grab a
prebuild GIMP package like GIMP.app, you most
probably want to stick
to that prebuild stuff. So you can try to get a prebuild version of
the plugin of you dreams from the author of the plugin, but I'd not
want to bet on this. Building your own binaries unfortunately involves
installing GIMP through one of the package managers
mentioned above.
1.4. Writing Plugins
If you want to learn how to write a plugin, you can find plenty of help
at the GIMP Developers web site
[ GIMP-DEV-PLUGIN ] .
GIMP is a complex
program, but the development team has made strenuous efforts to flatten
the learning curve for plugin writing: there are good instructions and
examples, and the main library that plugins use to interface with
GIMP (called “ libgimp ” ) has a
well-documented API . Good programmers, learning by
modifying existing plugins, are often able to accomplish interesting
things after just a couple of days of work.
6. Customize Splash-Screen 2. Using Script-Fu Scripts  Report an error in Bugzilla  4. The “Select” Menu 4. The “ Select ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. The “ Select ” Menu 4. 1. Introduction to the “ Select ” Menu Figure 16.26. The Contents of the “ Select ” menu
This section explains the commands on the Select
menu of the image menubar.
Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
3.22. Units 4.2. Select All
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4. 2. Select All 4. 2. Select All 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 2. Select All
The Select All command creates a new
selection which contains everything on the current layer.
 4. 2. 1. Activate the Command
You can access this command from the image menubar through
Select → All ,
or by using the keyboard shortcut
Ctrl + A .
In addition, at the
Selection Editor , you
can access it through the Tab menu :
Selection Editor Menu → All ,
or by clicking on the
icon button on the bottom of this dialog.  4. The “ Select ” Menu 4. 3. None
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4. 13. Border 4.13. Border 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 13. Border Figure 16.34. Example of creating a border from a selection
An image with a selection
After “ Select Border ”
The Select Border command creates a new
selection along the edge of an existing selection in the current image .
The edge of the current selection is used as a form and the new selection
is then created around it. You enter the width of the border , in pixels
or some other unit, in the dialog window. Half of the new border lies
inside of the selected area and half outside of it.
 4. 13. 1. Activating the Command
You can access this command from the image menubar through
Select → Border .  4. 13. 2. Description of the “ Border ” dialog window Figure 16.35. The “ Border ” dialog window Border selection by
Enter the width of the border selection in the box. The default
units are pixels, but you can also choose the units with the
drop-down menu.
Feather border
If this option is checked , the edges of the selection will be
feathered. This creates a smooth transition between the selection
and its surroundings. Note than you can't use the
Feather Edges option of the selection tools
for this purpose.
Lock selection to image edges
With this option enabled, an edge of an (usually rectangle)
selection remains unchanged if it is aligned with an edge of the
image; no new selection will be created around it.
Figure 16.36.
Select border with and without “ Lock to image
edges ”
Select border without (middle) and with (right) locked
selection.
Same selections filled with red.
4.12. Grow 4.14. Distort
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4. 6. By Color 4. 6. By Color 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 6. By Color
The Select By Color command is an alternate
way of accessing the “ Select By Color ” tool, one of the
basic selection tools. You can find more information about using this
tool in Select By Color .
 4. 6. 1. Activating the Command
You can access this command from the image menubar through
Select → By Color ,
or by using the keyboard shortcut
Shift + O .  4. 5. Float 4. 7. From Path
 Report an error in Bugzilla  4. 8. Selection Editor 4.8. Selection Editor 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 8. Selection Editor
The Selection Editor command displays the
“ Selection Editor ” dialog window . This dialog window
displays the active selection in the current image and gives you easy
access to the selection-related commands. It is not really intended for
editing selections directly, but if you are working on a selection, it
is handy to have the selection commands all together, since it is easier
to click on a button than to search for commands in the command tree of
the menubar. The “ Selection Editor ” also offers some
advanced options for the “ Select to Path ” command.
 4. 8. 1. Activating the Command
You can access this command from the image menubar through
Select → Selection Editor .  4. 8. 2.
Description of the “ Selection Editor ” dialog window
Figure 16. 27. The “ Selection Editor ” dialog window The Buttons
The “ Selection Editor ” dialog window has several
buttons which you can use to easily access selection commands:
The Select All
button.
The Select None
button.
The Select Invert
button.
The Save to
Channel button.
The To Path
button. If you hold the Shift key while
clicking on this button, the “ Advanced Settings ”
dialog is displayed. Please see the next section for details
about these options.
The Stroke
Selection button.
The display window
In the display window, selected areas of the image are white,
non-selected areas are black, and partially selected areas are
in shades of gray. Clicking in this window acts like
Select by Color .
See the example below.
Figure 16.28.
Example of clicking in the “ Selection Editor ” display
window
Clicking in the “ Selection Editor ” display window to “ Select By Color ” . Note that this figure could
just as well show the appearance of the
“ Selection Editor ” display window when
“ Select By Color ” is used in the image window.
4.8.3.
The “ Selection to Path Advanced Settings ” dialog
Figure 16.29. The “ Advanced Settings ” dialog window
The “ Selection to Path Advanced Settings ” dialog , that
you get by Shift clicking on the
Selection to Path button ,
contains a number of options, most of which you can set with either
a slider bar or a text box. There is also one check box. These
options are mostly used by advanced users. They are:
Align Threshold :
If two endpoints are closer than this value, they are made to be
equal.
Corner Always Threshold :
If the angle defined by a point and its predecessors
and successors is smaller than this, it is a corner ,
even if it is within Corner Surround
pixels of a point with a smaller angle.
Corner Surround :
Number of points to consider when determining if a
point is a corner or not.
Corner Threshold :
If a point, its predecessors, and its successors
define an angle smaller than this, it is a corner .
Error Threshold :
Amount of error at which a fitted spline [10]
is unacceptable. If any pixel is further away than this from the
fitted curve, the algorithm tries again.
Filter Alternative Surround :
A second number of adjacent points to consider
when filtering.
Filter Epsilon :
If the angles between the vectors produced by
Filter Surround and
Filter Alternative Surround
points differ by more than this, use the one from
Filter Alternative Surround .
Filter Iteration Count :
The number of times to smooth the original data points.
Increasing this number dramatically, to 50 or
so, can produce vastly better results. But if
any points that “ should ” be corners aren't found,
the curve goes wild around that point.
Filter Percent : To produce the new point,
use the old point plus this times the neighbors.
Filter Secondary Surround :
Number of adjacent points to consider if
Filter Surround points defines a
straight line.
Filter Surround :
Number of adjacent points to consider when filtering.
Keep Knees :
This check box says whether or not to remove “ knee ”
points after finding the outline.
Line Reversion Threshold :
If a spline is closer to a straight line than this value,
it remains a straight line, even if it would otherwise
be changed back to a curve. This is weighted by the
square of the curve length, to make shorter curves
more likely to be reverted.
Line Threshold :
How many pixels (on the average) a spline can
diverge from the line determined by its endpoints
before it is changed to a straight line.
Reparametrize Improvement :
If reparameterization doesn't improve the fit by this
much percent, the algorithm stops doing it.
Reparametrize Threshold :
Amount of error at which it is pointless to reparameterize.
This happens, for example, when the algorithm is trying to fit the
outline of the outside of an “ O ” with a single spline.
The initial fit is not good enough for the Newton-Raphson
iteration to improve it. It may be that it would be better
to detect the cases where the algorithm didn't find any corners.
Subdivide Search :
Percentage of the curve away from the worst point
to look for a better place to subdivide.
Subdivide Surround :
Number of points to consider when deciding whether
a given point is a better place to subdivide.
Subdivide Threshold :
How many pixels a point can diverge from a straight
line and still be considered a better place to
subdivide.
Tangent Surround :
Number of points to look at on either side of a
point when computing the approximation to the
tangent at that point.
[10] “ Spline ” is a mathematical term for a
function which defines a curve by using a series of control
points, such as a Bézier curve.
See Wikipedia for more information.
4.7. From Path 4. 9. Feather
 Report an error in Bugzilla 
4. 9. Feather 4. 9. Feather 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 9. Feather
The Feather command feathers the edges of
the selection . This creates a smooth transition between the selection
and its surroundings. You normally feather selection borders with the
“ Feather Edges ” option of the selection tools , but you
may feather them again with this command.
 4. 9. 1. Activating the Command
You can access this command from the image menubar through
Select → Feather .  4. 9. 2.
Description of the “ Feather Selection ” dialog window
Figure 16.30. The “ Feather Selection ” dialog Feather selection by
Enter the width of the selection border feathering. The default
units are pixels, but you can also choose other units with the
drop-down menu.
4. 8. Selection Editor 4.10. Sharpen
 Report an error in Bugzilla  4. 5. Float 4. 5. Float 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 5. Float
The Float command converts a normal selection
into a “ floating selection ” .
A floating selection (sometimes called a “ floating layer ” ) is
a type of temporary layer which is similar in function to a normal layer,
except that before you can resume working on any other layers in the
image , a floating selection must be anchored .
That is, you have to attach it to a normal (non-floating) layer, usually
the original layer (the one which was active previously), for instance, by
clicking on the image outside of the floating selection (see below).
Important
You cannot perform any operations on other layers while the image has a
floating selection!
You can use various operations to change the image data on the floating
selection. There can only be one floating selection in an image at a time.
Tip
If you display the layer boundary by using the
Show Layer Boundary
command , you may have difficulty selecting a precise area of the
image which you want in a layer. To avoid this problem, you can make a
rectangular selection, transform it into a floating selection and
anchor it to a new layer. Then simply remove the original layer.
In early versions of GIMP , floating
selections were used for performing operations on a limited part of an
image. You can do that more easily now with layers , but you can still
use this way of working with images.
 4. 5. 1. Activate the Command
You can access this command from the image menubar through
Select → Float ,
or by using the keyboard shortcut
Shift + Ctrl + L .  4. 5. 2. Creating a Floating Selection Automatically
Some image operations create a floating selection automatically:
The “ paste ” operations,
Paste Named Buffer ,
Paste or
Paste Into , also
create a floating selection.
In addition, the Transform tools,
Flip ,
Shear ,
Scale ,
Rotate and
Perspective ,
create a floating selection when they are used on a selection,
rather than a layer. When the Affect mode is
Transform Layer and a selection already exists,
these tools transform the selection and create a floating selection
with the result. If a selection does not exist, they transform the
current layer and do not create a floating selection. (If the
Affect mode is Transform
Selection , they also do not create a floating selection. )
By click-and-dragging a selection while pressing the
Ctrl + Alt keys
( see Section 2.1, “Moving a Selection” ) you also
automatically create a floating selection.
4.5.3. Anchor a Floating Selection You can anchor a floating selection in various ways:
You can anchor the floating selection to the current layer the
selection is originating from . To do this, click anywhere on the
image except on the floating selection. This merges the floating
selection with the current layer.
Or you can use the
Anchor layer command
( Ctrl + H ).
You can also anchor the floating selection to the current layer by
clicking on the anchor button of the
Layers dialog .
If you create a New Layer
while there is a floating selection , the floating selection is
anchored to this newly created layer.
4.4. Invert 4.6. By Color
 Report an error in Bugzilla  4. 12. Grow 4.12. Grow 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 12. Grow
The Grow command increases the size of a
selection in the current image . It works in a similar way to the
Shrink command, which
reduces the size of a selection .
 4. 12. 1. Activating the Command
You can access this command from the image menubar through
Select → Grow .  4. 12. 2. Description of the “ Grow Selection ” dialog Figure 16.32. The “ Grow Selection ” dialog window Grow selection by
You can enter the amount by which to increase the selection in
the text box. The default unit of measurement is pixels , but you
can choose a different unit by using the drop-down menu.
4. 12.3. A Peculiarity of Rectangular Selections
When you grow a rectangular selection, the resulting selection has
rounded corners. The reason for this is shown in the image below:
Figure 16.33.
Why growing a rectangular selection results in rounded corners
If you do not want rounded corners, you can use the
Rounded
Rectangle command with a 0% radius.
4.11. Shrink 4.13. Border
 Report an error in Bugzilla  4. 4. Invert 4.4. Invert 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 4. Invert
The Invert command inverts the selection
in the current layer. That means that all of the layer contents which
were previously outside of the selection are now inside it, and vice
versa. If there was no selection before, the command selects the
entire layer.
Warning
Do not confuse this command with the
Invert colors command.
 4. 4. 1. Activate the Command
You can access this command from the image menubar through
Select → Invert .
You can also use the keyboard shortcut
Ctrl + I ,
or click on the corresponding icon in the
Selection Editor  4. 3. None 4. 5. Float
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4. 3. None 4. 3. None 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 3. None
The None command cancels all selections in
the image. If there are no selections, the command doesn't do anything.
Floating selections are not affected.
 4. 3. 1. Activating the Command
You can access this command from the image menubar through
Select → None .
You can also use the keyboard shortcut
Shift + Ctrl + A .  In addition, at the
Selection Editor , you
can access it through the Tab menu :
Selection Editor Menu → None ,
or by clicking on the
icon button on the bottom of this dialog. 4.2. Select All 4. 4. Invert
 Report an error in Bugzilla  4. 10. Sharpen 4.10. Sharpen 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 10. Sharpen
The Sharpen command reduces the amount of
blur or fuzziness around the edge of a selection. It reverses the effect
of the Feather Selection
command. The new edge of the selection follows the dotted line of the
edge of the old selection. Anti-aliasing is also removed.
Note
Please do not confuse this command with the
Sharpen filter.
 4. 10. 1. Activating the Command
You can access this command from the image menubar through
Select → Sharpen .  4. 9. Feather 4. 11. Shrink
 Report an error in Bugzilla 
4. 11. Shrink 4.11. Shrink 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 11. Shrink
The Shrink command reduces the size of the
selected area by moving each point on the edge of the selection a
certain distance further away from the nearest edge of the image
( toward the center of the selection ). Feathering is preserved, but the
shape of the feathering may be altered at the corners or at points of
sharp curvature.
 4. 11. 1. Activating the Command
You can access this command from the image menubar through
Select → Shrink... .  4. 11. 2. Description of the “ Shrink ” dialog Figure 16.31. The “ Shrink Selection ” dialog Shrink selection by
Enter the amount by which to reduce the selection in the text
box. The default unit is pixels, but you can choose a different
unit of measurement from the drop-down menu.
Shrink from image border
This option is only of interest if the selection runs along
the edge of the image . If it does and this option is checked,
then the selection shrinks away from the edge of the image . If
this option is not checked, the selection continues to extend to
the image border.
4.10. Sharpen 4.12. Grow
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3. 17. Stroke Selection 3.17. Stroke Selection 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 17. Stroke Selection
The Stroke Selection command strokes a
selection in the image. There are two ways you can stroke the selection,
either by using a paint tool or without using one. This means that the
selection border, which is emphasized in the image with a dotted line,
can be drawn with a stroke. There are various options which you can use
to specify how this stroke should look.
Note
This command is only active if the image has an active selection.
 3. 17. 1. Activate the Command
You can access this command from the image menubar through
Edit → Stroke Selection .
You can also access it through the
Selection Editor .  3. 17.2. The “ Stroke Selection ” dialog Note
The options for stroking selections and for stroking paths
are the same. You can find the documentation about the options
in the dialog box in the
Stroke Path section.
3.16. Fill with Pattern 3.18. Stroke Path
 Report an error in Bugzilla  4. 17. Save to Channel 4.17. Save to Channel 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 17. Save to Channel The Save to Channel command saves the
selection as a channel. The channel can then be used as a channel
selection mask. You can find more information about them in the
Channel Dialog section.
You will find a simple example how to use this command in the introduction
of Section 16, “Alpha to Logo Filters” . It shows how to convert a
selection to an alpha channel so that you can apply an alpha to logo
filter to this selection.
 4. 17. 1. Activate the Command
You can access this command from the image menubar through
Select → Save to Channel .
You can also access it from the
Selection Editor .  4. 16. Toggle QuickMask 4. 18. To Path
 Report an error in Bugzilla  4. 18. To Path 4.18. To Path 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 18. To Path
The To Path command converts a selection
into a path . The image does not seem to change, but you can see the
new path in the Paths Dialog .
By using the Path tool in the
Toolbox, you can precisely adapt the outline of the selection. You can
find further information regarding paths in the
Paths dialog section.
 4. 18. 1. Activating the Command
You can access this command from the image menu bar through Select → To Path .
You can also access it from the
Selection Editor or
from the Paths Dialog
which offers you a lot of
Advanced
Options .  4. 17. Save to Channel 5. The “ View ” Menu
 Report an error in Bugzilla  3. 6. Tagging 3.6. Tagging 3. Image-content Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 6. Tagging
In Brushes, Gradients, Patterns and Palettes dialogs and some other
dockable dialogs, you can define tags and then, you can reorganize items
according to chosen tags only.
You have two input fields:
Figure 15.59. Tagging “ Filter ” field: There, you can enter a tag previously
defined or select a tag in the pop list you get by clicking on
the arrow head at the right end of the field. Brushes, gradients,
patterns, or palettes are filtered and only these that have this
chosen tag will be displayed.
You can enter several tags, separated with commas.
“ Enter tag ” field : There, tags belonging to the current
brush, gradient, pattern, or palette are displayed. You can add
another tag to the current item by clicking on one of the defined
tag in the pop up list of the field. You can also create your own
tag for this item by typing its name in the field. Then the new tag
appears in the tag pop up list.
Figure 15.60. Example
In this example, we defined a “ green ” tag for the Pepper
and Vine brushes. Then, we entered “ green ” in
the Filter input field and so, only
brushes with the green tag are displayed.
Tip
To give several brushes the same tag at once, display brushes in
List Mode, and use Ctrl +
Left click on the brushes you want to
select.
You can delete tags: select a brush, then select a tag in the “ Enter
tag ” field and press the Delete key. When this
tag has been removed from all brushes, it disappears from the list.
3.5. Palettes Dialog 3.7. Fonts Dialog  Report an error in Bugzilla  4. 4. Templates Dialog 4.4. Templates Dialog 4. Image Management Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 4. Templates Dialog Figure 15.69. The Templates dialog
Templates are templates for an image format to be created. GIMP offers you
a lot of templates and you can create your owns. When you create a New
image, you can access to the list of existing templates but you can't
manage them. The “ Templates ”
dialog allows you to manage all these templates.
 4. 4. 1. Activating the dialog
The “ Templates ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Templates .
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Templates . 
4. 4.2. Using the Templates dialog
You select a template by clicking on its icon. Right clicking reveals a
local menu that offers the same functions as buttons.
4.4.2.1. Grid/List modes
In the Tab menu for the “ Templates ” dialog , you can
choose between
View as Grid and View as
List . In Grid mode, templates are laid out in a
rectangular array of identical icons (unless you gave them a
particular icon, as we will see later). Only the name of the
selected template is displayed. In List mode, they are lined up
vertically; icons are identical too; all names are displayed.
In this Tab menu, the Preview Size option allows
you to change the size of thumbnails.
Tip Ctrl + F
in a list view opens a search field.
See View as List; View as Grid
4.4.2.2. Buttons at the bottom
The buttons at the bottom of the dialog allow you to operate on
templates in several ways:
Create a new image from the selected template
Clicking on this button opens the dialog
Create a new image
on the model of the selected template.
Create a new template
Clicking on this button opens the
New template
dialog, identical to the Edit Template dialog, that we will see
below.
Duplicate the selected template
Clicking on this button opens the Edit Template dialog that we
are going to study now.
Edit the selected template
Clicking on this button opens the
Edit Template
dialog .
Delete the selected template Guess what? Tip
Every template is stored in a templaterc
file at your personal GIMP directory.
If you want to restore some deleted templates, you can copy or
append template entries to your file from the master
templaterc file at the
etc/gimp/2.0 directory
of the GIMP 's system folder.
4.4.3. Edit Template Figure 15.70. The Edit Template dialog
The dialog allows you to set the specifications of the selected template.
You can access this editor by clicking on the
Edit Template button at the bottom of the dialog .
Options Name
In this text box , you can modify the displayed template name.
Icon
By clicking on this icon, you open a list of icons. You can choose
one of them to illustrate the selected template name.
Image size
Here you set the width and height of the new image. The
default units are pixels, but you can switch to some other
unit if you prefer, using the adjoining menu. If you do,
note that the resulting pixel size will be determined by
the X and Y resolution (which you can change in the
Advanced Options), and by the setting of
“ Dot for Dot ” , which you can change in the
View menu.
Note
Please keep in mind, that every Pixel of an image is stored
in the memory. If you're creating large files with a high
density of pixels, GIMP will need some
time for every function you're applying to the image.
Portrait/Landscape buttons
These buttons toggle between Portrait and Landscape mode.
Concretely, their effect is to exchange the values for
Width and Height. If the X and Y resolutions are
different ( in Advanced Options), then these values are
exchanged also. On the right, image size, image resolution and
color space are displayed.
Advanced Options
Figure 15.71. The “ Advanced Options ” dialog
These are options that will mainly be of interest to more advanced
users.
X and Y resolution
These values come into play mainly in relation to
printing: they do not affect the size of the image in
pixels, but they determine its size on paper when
printed. They can also affect the way the image is
displayed on the monitor: if “ Dot for Dot ” is
switched off
in the View menu, then at 100% zoom,
GIMP attempts to display the image on the monitor at the
correct physical size, as calculated from the pixel
dimensions and the resolution. The display may not be
accurate, however, unless the monitor has been calibrated.
This can be done either when GIMP is installed, or from
the Display tab of
the Preferences dialog.
Colorspace
You can create the new image as either an RGB image or a grayscale
image. You cannot create an indexed image directly in this way, but
of course nothing prevents you from converting the image to indexed
mode after it has been created.
Fill
You have four choices for the solid color that will fill
the new image's background layer:
Foreground color , as shown in the Main
Toolbox.
Background color , as shown in the Main
Toolbox.
White , the more often used.
Transparent . If this option is chosen,
then the Background layer in the new image will be created
with an alpha channel ; otherwise not.
Comment
You can write a descriptive comment here. The text will
be attached to the image as a “ parasite ” , and will be
saved along with the image by some file formats ( but not
all of them).
4.3. Document History Dialog 5. Misc. Dialogs
 Report an error in Bugzilla  2. Text Tool Box 2. Text Tool Box Chapter 9. Text Management  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Text Tool Box Figure 9.6. Text Tool Box
You get this box, which overlays canvas, as soon as you click on canvas with
the Text Tool. It allows you to edit text directly on canvas.
Apart from the usual text formatting features like font family, style and
size selectors you get numeric control over baseline offset and kerning, as
well as the ability to change text color for a selection.
Help pop-ups are self-explanatory.
You can also use Alt + Arrow keys to change baseline offset and kerning.
Important
These features work on selected text. You get weird effects if no text is
selected.
2.1. Text Tool Box Context menu
TODO
Chapter 9. Text Management 3. Text
 Report an error in Bugzilla  12.4. Tip of the Day 12. 4. Tip of the Day 12. The “ Help ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12.4. Tip of the Day The Tip of the Day command displays the
Tip of the Day dialog. This dialog contains useful
tips to help you gain a better understanding of some of the subtle
points of using GIMP .
New users will find it very valuable to pay attention to these,
because they often suggest ways of doing something that are much
easier or more efficient than more obvious approaches.
 12. 4. 1. Activating the Command
You can access this command in the image menu through
Help → Tip of the Day .  12. 4. 2. Description of the dialog window Figure 16. 209. “ Tip of the Day ” Dialog window
Some tips contain a Learn more link to the
corresponding GIMP manual page.
New in GIMP 2.6
The tip of the day is no longer displayed by default each time you
start GIMP .
12.3. Context Help 12.5. About
 Report an error in Bugzilla 
3. 9. Airbrush 3.9. Airbrush 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 9. Airbrush Figure 14.76. The Airbrush tool in Toolbox
The Airbrush tool emulates a traditional airbrush. This tool is suitable
for painting soft areas of color.
 3.9. 1. Activating the Tool You can activate the Airbrush tool in several ways :
From the image-menu, through :
Tools → PaintTools → Airbrush
By clicking on the tool icon :
in the Toolbox,
By using the A keyboard shortcut. 
3.9. 2. Key modifiers (Defaults) Ctrl Ctrl changes the airbrush to a
Color Picker .
Shift Shift places the airbrush into straight
line mode. Holding Shift while clicking
Button 1 will generate a straight
line. Consecutive clicks will continue drawing straight lines
that originate from the end of the last line.
3. 9. 3. Options Figure  14. 77. Airbrush options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity ; Brush; Size; Dynamics; Dynamic Options; Fade Options;
Color Options; Apply Jitter
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Rate
The Rate
slider adjusts the speed of color application that the airbrush
paints. A higher setting will produce darker brush strokes in a
shorter amount of time.
Flow
This slider controls the amount of color that the airbrush paints.
A higher setting here will result in darker strokes.
3.8. Eraser 3.10. Ink
 Report an error in Bugzilla 
4. 2. Align 4.2. Align 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 2. Align Figure 14.106. The Align tool in the toolbox
The Align tool is useful to align the image layers with various
image objects. When this tool is selected, the mouse pointer turns
to a small hand . By clicking on an element of a layer in the
image , you choose the layer which will be moved (with Shift
+ click, you can choose several layers to be aligned);
this focalised layer has small squares in corners.
Various buttons in the dialog allow you to select how the layer
will be moved. And you can select the image object (other layer,
selection, path...) the selected layer will be aligned on. This
object is called target .
4. 2. 1. Activating the Tool You can activate the Align tool in several ways :
From the image-menu, through:
Tools → Transform Tools → Align ,
by clicking on the tool icon :
in the toolbox,
by using the Q keyboard shortcut.
4. 2. 2. Key modifiers (Defaults) Shift
You can select several layers by holding Shift
when clicking the layers.
Tip
Sometimes it's easier to choose multiple layers using
rubber-banding : click somewhere outside an imaginary rectangular
region covering the layers you want to choose. Then drag out
that region by moving the pointer, and release the mouse button .
Now every layer, which is completely inside the dragged
rectangle, is selected.
Note that now there is no target “ first item ” the
selected layers can be aligned on.
4.2. 3. Tool Options Figure  14. 107. Tool Options for the Align tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Align Relative to:
This is the target - the image object the selected layer
will be aligned on.
First item : the first selected
item when selecting multiple layers holding the
Shift
key. Note that there is no “ first item ”
when you select multiple layers using rubber-banding .
Image : the image is used as a
target.
Selection : the minimal rectangular
region covering the active selection.
Active layer : Active Channel : Active Path :
These buttons become active when a layer is selected.
When you click on one of these buttons , you align the
selected layer with left edge, horizontal middle, right edge,
top edge, vertical middle, or bottom of the target.
Distribute
These options seem to differ from the “ Related to
” options only by the possibility to set an
offset. This offset is the distance which will
separate the selected layer(s) from the target once the
alignment is performed. It can be positive or negative
and is expressed in pixel. Distribute add this offset to
the left edges, horizontal centers, right edges, top
edges, vertical centers, or bottoms of targets.
Offset
This entry controls the amount of displacement that could
be given to the desired alignment effect (in pixel)
regarding the target. The default value is 0; it can be
positive or negative .
4.2.4. Example for the “ Align ” command Figure 14.108. Base image
This image has three layers with different sizes and a
rectangular selection. The yellow layer is active.
Figure 14.109. Red layer selected
Click on red: the red layer is selected, with a small square
in every corner.
Figure 14.110. Red layer aligned
We chose “ Selection ” as a target and we clicked
on the
button ( Related to). The red layer alignes with
the right side of the selection.
Figure 14.111. Distribute with offset
We set Offset to -5, we chose “ Active layer ” as a
target and we clicked on the
button ( Distribution).
The layer is aligned 5 pixels before the right side of the
yellow active layer.
Figure 14.112. Align using rubber-band box
We clicked left from and above the red layer, and dragged out a
region covering the red and the yellow layer by moving the pointer
towards the bottom right corner.
Again, Selection is the target. After a click
on the
button , both layers aligne with the left side of the
selection.
4. Transform Tools 4.3. Move
 Report an error in Bugzilla 
3. 5. Blend 3.5. Blend 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 5. Blend Figure 14.62. The Blend tool in Toolbox
This tool fills the selected area with a gradient blend of the foreground
and background colors by default, but there are many options. To make a
blend, drag the cursor in the direction you want the gradient to go, and
release the mouse button when you feel you have the right position and
size of your blend. The softness of the blend depends on how far you drag
the cursor. The shorter the drag distance, the sharper it will be.
There are an astonishing number of things you can do with this tool, and
the possibilities may seem a bit overwhelming at first. The two most
important options you have are the Gradient and the Shape. Clicking the
Gradient button in the tool options brings up a Gradient Select window,
allowing you to choose from among a variety of gradients supplied with
GIMP; you can also construct and save custom gradients. Further
information about gradients can be found in
Section 10, “Gradients” and
Section 3.4, “Gradients Dialog” .
For Shape, there are 11 options: Linear, Bilinear, Radial, Square, Conical
(symmetric), Conical (asymmetric), Shaped (angular), Shaped (spherical),
Shaped (dimpled) , Spiral (clockwise), and Spiral (counterclockwise); these
are described in detail below. The Shaped options are the most
interesting: they cause the gradient to follow the shape of the selection
boundary, no matter how twisty it is. Unlike the other shapes, Shaped
gradients are not affected by the length or direction of the line you
draw: for them as well as every other type of gradient you are required to
click inside the selection and move the mouse, but a Shaped appears the
same no matter where you click or how you move.
Tip
Check out the Difference option in the Mode menu, where doing the same
thing (even with full opacity) will result in fantastic swirling
patterns, changing and adding every time you drag the cursor.
 3. 5. 1. Activating the Tool
There are different possibilities to activate the tool:
From the image-menu :
Tools → Paint Tools → Blend .
By clicking the tool icon
.
By clicking on the L keyboard shortcut. 
3. 5. 2. Key modifiers (Defaults) Ctrl Ctrl is used to create straight lines that are
constrained to 15 degree absolute angles.
3.5. 3. Options Figure  14. 63. “ Blend ” tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Gradient
A variety of gradient patterns can be selected from the drop-down
list. The tool causes a shading pattern that transitions from
foreground to background color or introducing others colors, in
the direction the user determines by drawing a line in the image.
For the purposes of drawing the gradient, the
Reverse
check-box reverse the gradient direction with the effect, for
instance, of swapping the foreground and background colors.
Offset
The Offset value permits to increase the
“ slope ” of the gradient. It determines how far
from the clicked starting point the gradient will begin.
Shaped forms are not affected by this option.
Figure 14.64. “ Blend ” tool: Offset example Top, Offset = 0 ; Bottom, Offset = 50% Shape
The GIMP
provides 11 shapes, which can be selected from the drop-down list.
Details on each of the shapes are given below.
Figure 14.65. Examples of gradient shapes Linear Bi-Linear Radial Linear
This gradient begins with the foreground color at the
starting point of the drawn line and transitions linearly to
the background color at the ending point.
Bi-Linear
This shape proceeds in both directions from the starting
point, for a distance determined by the length of the drawn
line. It is useful, for example, for giving the appearance
of a cylinder.
Radial
This gradient gives a circle, with foreground color at the
center and background color outside the circle. It gives the
appearance of a sphere without directional lighting.
Square; Shaped Figure 14.66. Square-shaped gradient examples Square
Shaped (angular)
Shaped (spherical)
Shaped (dimpled)
There are four shapes that are some variant on a
square: Square ,
Shaped (angular) ,
Shaped (spherical) , and
Shaped (dimpled) . They all
put the foreground color at the center of a square,
whose center is at the start of the drawn line, and
whose half-diagonal is the length of the drawn line.
The four options provide a variety in the manner in
which the gradient is calculated; experimentation is
the best means of seeing the differences.
Conical (symmetric); Conical (asymmetric) Figure 14.67. Conical gradient examples
Conical (symmetrical)
Conical (asymmetrical)
The Conical (symmetrical) shape
gives the sensation of looking down at the tip of a
cone, which appears to be illuminated with the
background color from a direction determined by the
direction of the drawn line.
Conical (asymmetric) is similar to
Conical (symmetric) except that
the "cone" appears to have a ridge where the line is
drawn.
Spiral (clockwise); Spiral
(counterclockwise) Figure 14.68. Spiral gradient examples
Spiral (clockwise)
Spiral (counterclockwise)
The Spiral shape provide spirals
whose repeat width is determined by the length of
the drawn line.
Repeat
There are two repeat modes: Sawtooth Wave
and Triangular Wave . The Sawtooth
pattern is achieved by beginning with the foreground,
transitioning to the background, then starting over with the
foreground. The Triangular starts with the foreground,
transitions to the background, then transitions back to the
foreground.
Dithering
Dithering is fully explained in the
Glossary
Adaptive Supersampling
This a more sophisticated means of smoothing the "jagged" effect
of a sharp transition of color along a slanted or curved line.
Only tests can allow you to choose.
3.4. Bucket Fill 3. 6. Pencil
 Report an error in Bugzilla  5. 5. Brightness-Contrast 5. 5. Brightness-Contrast 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 5. Brightness-Contrast
The Brightness-Contrast tool adjusts the brightness and contrast levels
for the active layer or selection. This tool is easy to use, but
relatively unsophisticated. The Levels and Curve tools allow you to make
the same types of adjustments, but also give you the ability to treat
bright colors differently from darker colors. Generally speaking, the BC
tool is great for doing a "quick and dirty" adjustment in a few seconds,
but if the image is important and you want it to look as good as possible,
you will use one of the other tools.
In GIMP 2.4 , a new way of operating this tool has been added: by
clicking the mouse inside the image, and dragging while keeping the
left mouse button down. Moving the mouse vertically changes the
brightness; moving horizontally changes the contrast. When you are
satisfied with the result, you can either press the
OK button on the dialog, or hit the
Return key on your keyboard.
5. 5. 1. Activating the Tool
You can get to the Brightness-Contrast tool in two ways:
In the image-menu through:
Tools → Color Tools → Brightness-Contrast or
Colors → Brightness-Contrast ,
by clicking the tool icon :
in Toolbox , provided that you have installed color tools in Toolbox.
For this, please refer to Section 1.7, “Toolbox” .
5. 5.2. Options Figure 14.150. Brightness-Contrast options dialog Presets
You can save the color settings of your image by clicking the
Add settings to favourites button
The
button opens a menu:
Figure 14. 151. Preset Menu
which lets you Import Settings from File or
Export Settings to File ,
and gives you access to the Manage Save Settings dialog:
Figure 14. 152. Manage saved Settings Dialog Brightness
This slider sets a negative (to darken) or positive (to brighten)
value for the brightness, decreasing or increasing bright tones.
Contrast
This slider sets a negative (to decrease) or positive (to
increase) value for the contrast.
Edit these settings as Levels
To make your work easier, this button lets you turn to the
Levels tool with the same
settings.
Preview
The Preview check-box makes all changes to the brightness and
contrast dynamically so that the new level settings can be viewed
immediately.
5. 4. Colorize 5.6. Threshold
 Report an error in Bugzilla  3. 4. Bucket Fill 3. 4. Bucket Fill 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 4. Bucket Fill Figure 14.58. Toolbox Fill
This tool fills a selection with the current foreground color . If you
Ctrl +click and use the Bucket tool, it will use the
background color instead. Depending on how the tool options are set, the
Bucket Fill tool will either fill the entire selection, or only parts
whose colors are similar to the point you click on. The tool options also
affect the way transparency is handled.
The amount of fill depends on what Fill Threshold you have specified. The
fill threshold determines how far the fill will spread (similar to the way
in which the magic wand works). The fill starts at the point where you
click and spreads outward until the color or alpha value becomes
“ too different ” .
When you fill objects in a transparent layer (such as letters in a text
layer) with a different color than before, you may find that a border of
the old color still surrounds the objects. This is due to a low
fill-threshold in the Bucket Fill options dialog. With a low threshold,
the bucket tool won't fill semi-transparent pixels, and they will stand
out against the fill because they have kept their original color.
If you want to fill areas that are totally transparent, you have to make
sure that the “ Lock ” option ( in the Layers dialog ) is
unchecked. If this option is checked , only the non-transparent parts of
the layer will be filled.
 3. 4. 1. Activating the tool
You can find the Bucket Fill tool from the image-menu through:
Tools → Paint Tools → Bucket Fill
You can also call it by clicking the tool icon :
in the toolbox.
or by pressing the
Shift + B keys. 
3. 4.2. Key modifiers (Defaults) Ctrl toggles the use of BG Color Fill or FG
Color Fill on the fly.
Shift toggles the use of Fill Similar Color or
Fill Whole Selection on the fly.
3.4. 3. Options Figure  14. 59. “ Bucket Fill ” tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity
See Paint Tools
for help with options that are common to all these tools. Only
options that are specific to the Bucket Fill tool are
explained here.
Fill Type GIMP provides three fill types:
FG Color Fill
sets the fill color to the currently selected foreground
color.
BG Color Fill
sets the fill color to the currently selected background
color.
Pattern Fill
sets the fill color to the currently selected pattern. You
can select the pattern to use in a drop down list .
This drop-down list allows the user to select one of many
fill patterns to use on the next fill operation. The manner
in which the list is presented is controlled by the four
buttons at the bottom of the selector.
Affected Area Fill whole selection
This option makes GIMP fill a pre-existent selection or the
whole image. A quicker approach to do the same thing could
be to click and drag the foreground, background or pattern
color, leaving it onto the selection.
Fill similar colors
This is the default setting: the tool fills the area with a
color near the pixel onto you have clicked. The color
similarity is defined by a brightness threshold, that you
can set by a value or by a cursor position.
Finding Similar Colors Under this section you can find two options: Fill Transparent Areas
The option Fill Transparent Areas
offers the possibility of filling areas with low opacity.
Sample Merged
The option Sample Merged
toggles the sampling from all layers. If Sample Merged is
active, fills can be made on a lower layer, while the color
information used for threshold checking is located further
up. Simply select the lower level and ensure that a layer
above is visible for color weighting.
Threshold
The Threshold slider sets the level at which color weights
are measured for fill boundaries. A higher setting will fill
more of a multi colored image and conversely, a lower
setting will fill less area.
Fill by
With this option you can choose which component of the image
GIMP shall use to calculate the similarity and to determine
the borders of filling.
The components you can choose from are
Composite ,
Red ,
Green ,
Blue ,
Hue ,
Saturation and
Value .
This option is not easy to understand. You have chosen,
for example, the Red channel. When you click on any pixel,
the tool searches for contiguous pixels similar for
the red channel to the clicked pixel,
according to the set threshold. Here is an example:
Original image: three strips with gradients of pure
colors. Red (255;0;0), Green (0;255;0), Blue
(0;0;255). We are going to use the Bucket-fill tool
with the magenta color and a Threshold set to 15.
Image 1: Fill By = Composite. We successively clicked in the
three color strips. Every strip is filled according
to the threshold.
Image 2: Fill By = Red. We clicked in the red strip. The
tool searches for contiguous pixels which have a similar
value in the red channel, according to the set
threshold. Only a narrow area corresponds to these
standards. In the green and the blue strip, the value
of pixels in the red channel is 0 , very much different from
the red channel value of the clicked pixel : the color
doesn't spread to them.
Image 3: Fill By = Red. We clicked in the green strip.
There, the value of the clicked pixel in the red channel is
0 . All pixels in the green and the blue strips have the
same red channel value (0): they are all painted.
Figure 14.60. Example for “ Fill By ” Original image Image 1 Image 2 Image 3 3.4.4. Fill a feathered selection
By clicking repeatedly in a selection with feathered edges, you
progressively fill the feathered border:
Figure 14.61. Example for “ Fill a feathered Selection ” Original image
After clicking 3 times more with the Bucket-Fill tool
3.3. Brush Tools (Pencil, Paintbrush, Airbrush) 3.5. Blend
 Report an error in Bugzilla  2. 6. Select By Color 2.6. Select By Color 2. Selection Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 6. Select By Color Figure 14.24. Select by Color tool icon in the Toolbox
The Select by Color tool is designed to select areas of an image
based on color similarity. It works a lot like the Fuzzy Select
tool ( “ Magic Wand ” ). The main difference between them is
that the Magic Wand selects contiguous regions, with
all parts connected to the starting point by paths containing no
large gaps; while the Select by Color tool selects all pixels that
are sufficiently similar in color to the pixel you click on ,
regardless of where they are located.
 2. 6. 1. Activating the tool
You can access the Select by Color Tool in different ways:
From the image menu bar
Tools → Selection Tools → By Color Select ,
by clicking on the tool icon
in the ToolBox,
by using the keyboard shortcut Shift
+ O . 
2. 6. 2. Key modifiers (Defaults) The select by color tool does not have any special key modifiers,
only the ones that affect all selection tools in the same way.
See Selection Tools for
help with these.
2. 6.3. Handling tool Figure 14.25.
Using Select by Color tool: selected pixels are not only contiguous
As with fuzzy tool, the selection starts as soon as you click and the
reference is the first clicked pixel. If you click and drag , you can
change the threshold by the same way as with the fuzzy tool.
To move the selection see
Moving selections .
2. 6.4. Options Figure  14. 26. Tool Options for the Select by Color tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Note
See Selection Tools
for help with options that are common to all these tools. Only
options that are specific to this tool are explained here.
Mode; Antialiasing; Feather edges
Common select options. Similar colors
All these options work exactly the same way, they were described
for the fuzzy selection already. See for
Section 2. 5.4, “Options” details.
2.5. Fuzzy selection (Magic wand) 2. 7. Intelligent Scissors
 Report an error in Bugzilla  4. 10. The Cage Tool 4.10. The Cage Tool 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 10. The Cage Tool Figure 14.135. The Cage Tool in the Toolbox
The Cage tool is a special transforming tool allowing you to select the
transforming area by setting anchor points by free hand drawing similar
to the way you do it with the Free Selection (Lasso) tool. The tool adds
nothing to the image until you confirm the transformation by pressing the
Enter key.  4. 10. 1.
Activating the Tool
You can activate the Cage tool in several ways:
From the image-menu, through:
Tools → Transform Tools → Cage Transform
by clicking on the tool icon :
in the toolbox
or by using the Shift G keyboard shortcut.  4. 10.2. Tool Options Figure  14. 136. Cage Tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options
which opens the option window of the selected tool.  Create or adjust the cage
When activating the Cage Tool this option is selected. You can now
click in the image to make anchor points around the desired area.
If you need to add anchor points at a later stage, you click on
this option.
Deform the cage to deform the image GIMP switch to this option automatically when the
cage outline is finished. Now you are able to drag the anchor points
around in the image and even outside it to transform the picture.
The transforming starts when you release the mouse button .
You can activate more than one anchor point by holding down the
Shift key while clicking on the points. You can
also select more points by holding down the mouse button while
drawing a rectangle around the desired points.
Fill the original position of the cage with a plain color
If the transforming action results in empty areas these areas will
be filled with color if this option is checked . It looks like the
color is picked from the start pixel of the cage line.
4.10.3. Example for the “ Cage ” tool Figure 14.137. Cage Tool example The cage area selected Transformed
When clicking on the cage icon in the toolbox the cage option is set to
“ Create or adjust the cage ” . You are now able to draw a cage
outline in the image by successively clicking around the area you want to
transform. Click on the starting point to finish the selection.
GIMP will then do some mathematics and activate the
“ Deform the cage to deform the image ” to allow you to drag
the points on the line to deform the cage and the image.
The selected point(s) turns to a square. Drag the points around in the
image to transform it. The transforming will occur every time you release
the press on the mouse button. The transforming may take some time so be
patient especially when working with large images.
If you desire to add more points to the line you have to select the “ Create or adjust the cage ” in the tool options dialog.
Put the points on the line and switch back to the “ Deform the cage
to deform the image ” to transform the image or layer .
When the work is done, press the Enter key to confirm it.
4.9. Flip 5. Color Tools
 Report an error in Bugzilla  3. 11. Clone 3.11. Clone 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 11. Clone Figure 14.80. Clone tool icon in the Toolbox
The Clone tool uses the current brush to copy from an image or pattern.
It has many uses: one of the most important is to repair problem areas in
digital photos, by “ painting over ” them with pixel data from
other areas. This technique takes a while to learn, but in the hands of a
skilled user it is very powerful. Another important use is to draw
patterned lines or curves: see
Patterns for examples.
If you want to clone from an image, instead of a pattern, you must tell
GIMP which image you want to copy from. You do this by holding down the
Ctrl key and clicking in the desired source image.
Until you have set the source in this way, you will not be able to paint
with the Clone tool: the tool cursor tells you this by showing
.
If you clone from a pattern, the pattern is tiled ;
that is, when the point you are copying from moves past one of the
edges, it jumps to the opposite edge and continues, as though the pattern
were repeated side-by-side, indefinitely. When you clone from an image
this does not happen: if you go beyond the edges of the source, the Clone
tool stops producing any changes.
You can clone from any drawable (that is, any layer, layer mask, or
channel) to any other drawable. You can even clone to or from the
selection mask, by switching to QuickMask mode. If this means copying
colors that the target does not support (for example, cloning from an RGB
layer to an Indexed layer or a layer mask), then the colors will be
converted to the closest possible approximations.
3.11. 1. Activating the tool You can activate this tool in several ways :
From the image menu through
Tools → Paint Tools → Clone .
By clicking on the tool icon
in Toolbox .
By pressing the C keyboard shortcut.
3.11.2. Key modifiers (default)
See the Paint tools key
modifiers for a description of key modifiers that have the same
effect on all paint tools.
Ctrl
The Ctrl key is used to select the source , if
you are cloning from an image: it has no effect if you are
cloning from a pattern. You can clone from any layer of any
image, by clicking on the image display, with the
Ctrl key held down, while the layer is active
(as shown in the Layers dialog). If Alignment is set to
None , Aligned , or
Fixed in tool options, then the point you
click on becomes the origin for cloning: the image data at that
point will be used when you first begin painting with the Clone
tool . In source-selection mode, the cursor changes to a reticle
cross symbol
.
3.11. 3. Options Figure  14. 81. Tool Options for the Clone tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity; Brush; Dynamics; Dynamics Options;
Fade Options; Apply Jitter; Smooth Stroke; Hard Edge
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Source
The choice you make here determines whether data will be copied
from the pattern shown above, or from one of the images you have
open.
Image
If you choose Image source , you must
tell GIMP which layer to use as the
source, by Ctrl -clicking on it, before
you can paint with the tool.
If you check Sample merged it's what
you “ see ” (color made with all the layers of
a multi-layer image) that's cloned. If it's unchecked,
only the selected layer is cloned. For more information
see the glossary entry Sample Merge .
Pattern
Clicking on the pattern symbol brings up the Patterns
dialog, which you can use to select the pattern to paint
with. This option is only relevant if you are cloning from a
Pattern source.
Alignment
The Alignment mode defines the relation between the brush
position and the source position.
In the following examples, we will use a source image where the
sample to be cloned will be taken, and a destination image where
the sample will be cloned (it could be a layer in the source
image)
Figure 14.82. Original images for clone alignment
We will use the largest brush with the Pencil tool. The
source is represented here with a ringed cross.
An image with a solid background only. We shall draw three
cloning strokes successively.
None
In this mode, each brushstroke is treated separately. For
each stroke, the point where you first click is copied from
the source origin; there is no relationship between one
brush stroke and another. In non-aligned mode, different
brush strokes will usually clash if they intersect each
other.
Example below: At every new brush stroke, the source goes
back to its first position. The same sample is always
cloned.
Figure 14.83. “ None ” clone alignment Aligned
In this mode, the first click you make when painting sets
the offset between the source origin and the cloned result,
and all subsequent brushstrokes use the same offset. Thus,
you can use as many brushstrokes as you like, and they will
all mesh smoothly with one another.
If you want to change the offset, select a new source origin
by clicking with the Ctrl key pressed .
In the example below, at every new brush stroke, the source
keeps the same offset it had with the previous brush stroke.
So, there is no cloning offset for the first brush stroke.
Here, for the following strokes, the source ends up out of
the source image canvas; hence the truncated aspect.
Figure 14.84. “ Aligned ” clone alignment Registered
The “ Registered ” mode is different from the
other alignment modes. When you copy from an image, a
Ctrl -click will register a source layer.
Then painting in a target layer will clone each
corresponding pixel (pixel with the same offset) from the
source layer. This is useful when you want to clone parts
of an image from one layer to another layer within the same
image. (But remember that you can also clone from one image
to another image.)
At every brush stroke, the source adopts the position of the
mouse pointer in the destination layer. In the following
example, the destination layer is smaller than the source
layer; so, there is no truncated aspect.
Figure 14.85. “ Registered ” clone alignment Fixed
Using this mode you will paint with the source origin,
unlike the modes None or
Aligned even when drawing a line. The
source will not be moved.
See that the source remains fixed. The same small sample is
reproduced identically in a tightened way:
Figure 14.86. “ Fixed ” clone alignment 3.11.4. Further Information Transparency
The effects of the Clone tool on transparency are a bit
complicated. You cannot clone transparency: if you try to clone
from a transparent source, nothing happens to the target. If you
clone from a partially transparent source, the effect is weighted
by the opacity of the source. So, assuming 100% opacity and a hard
brush:
Cloning translucent black onto white produces gray.
Cloning translucent black onto black produces black.
Cloning translucent white onto white produces white.
Cloning translucent white onto black produces gray.
Cloning can never increase transparency, but, unless “ keep
transparency ” is turned on for the layer, it can reduce
it.
Cloning an opaque area onto a translucent area produces an opaque
result; cloning a translucent area onto another translucent area
causes an increase in opacity.
“ Filter ” brushes
There are a few non-obvious ways to use the Clone tool to obtain
powerful effects. One thing you can do is to create “ Filter
brushes ” , that is, create the effect of applying a filter
with a brush. To do this, duplicate the layer you want to work
on , and apply the filter to the copy. Then activate the Clone
tool, setting Source to “ Image source ” and Alignment
to “ Registered ” . Ctrl -click on the
filtered layer to set it as the source, and paint on the original
layer: you will then in effect be painting the filtered image
data onto the original layer.
History brush
You can use a similar approach to imitate Photoshop's
“ History brush ” , which allows you to selectively
undo or redo changes using a brush. To do this, start by
duplicating the image; then, in the original, go back to the
desired state in the image's history, either by undoing or by
using the Undo History dialog . (This must be done in the
original, not the copy, because duplicating an image does not
duplicate the Undo history.) Now activate the Clone tool,
setting Source to “ Image source ” and Alignment to
“ Registered ” . Ctrl -click on a layer
from one image, and paint on the corresponding layer from the
other image. Depending on how you do it, this gives you either
an “ undo brush ” or a “ redo brush ” .
3.10. Ink 3.12. Heal
 Report an error in Bugzilla  5. 2. Color Balance 5. 2. Color Balance 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 2. Color Balance
The color balance tool modifies the color balance of the active selection
or layer . Changes are not drastic. This tool is suitable to correct
predominant colors in digital photos.
 5. 2. 1. Activating the Tool
You can get to the Color balance tool in several ways :
In the image-menu through:
Tools → Color Tools → Color Balance , or
Colors → Color Balance ,
by clicking the tool icon :
in Toolbox , provided that you have installed color tools in Toolbox.  For this, please refer to Section 1.7, “Toolbox” .
5. 2.2. Options Figure 14.140. Color Balance options Presets
You can save the color settings of your image by clicking the
Add settings to favourites button
The
button opens a menu:
Figure 14. 141. Preset Menu
which lets you Import Settings from File or
Export Settings to File ,
and gives you access to the Manage Save Settings dialog:
Figure 14. 142. Manage saved Settings Dialog Select range to adjust
Selecting one of these options will restrict the range of colors
which are changed with the sliders or input boxes for Shadows
(darkest pixels), Midtones (medium pixels) and Highlights
(brightest pixels).
Adjust color levels
Sliders and range from the three RGB colors to their
complementary colors (CMY). The zero position corresponds to
the current level value of pixels in the original image. You can
change the pixel color either towards Red or Cyan, Green or
Magenta, Blue or Yellow.
Reset Range
This button sets color levels of the selected range back to
the zero position (original values).
Preserve Luminosity
This option ensures that brightness of the active layer or
selection is maintained. The Value of brightest pixels is not
changed.
Preview
The Preview checkbox toggles dynamic image updating. If this
option is on, any change made to the RGB levels are immediately
seen on the active selection or layer .
5. Color Tools 5.3. Hue-Saturation
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6. 3. Color Picker 6.3. Color Picker 6. Other  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 3. Color Picker Figure 14.180. The Color Picker in the toolbox (eye dropper icon)
The Color Picker Tool is used to select a color on any image opened on
your screen. By clicking a point on an image, you can change the active
color to that which is located under the pointer. By default, the tool
works on the active layer , but the Sample Merge
option lets you grab the color as it is in the image, resulting of the
combination of all layers.
Only colors in visible layers are used . An
Info window opens when you click on the image.
6. 3. 1. Activating the Tool You can get to this tool in several ways :
In the image menu through
Tools → Color Picker. ,
by clicking the tool icon
in Toolbox ,
by pressing the O keyboard shortcut,
by pressing the Ctrl key while using a paint
tool. The Color-picker dialog is not opened during this operation
and the tool remains unchanged after releasing the key.
Nevertheless, you can get information by using the
Pointer window .
6.3.2. Key modifiers (Defaults) Ctrl
If the pick mode is set to Set foreground
color , then pressing the Ctrl key
switches the tool into the Set background
color mode. If the pick mode is set to Set
background color then the key switches the mode to
Set foreground color .
When the pick mode is Pick only , the key
doesn't do anything.
Shift
By pressing the Shift key , the
Color Picker Information window is opened
when you click on a pixel .
Note
The Pointer
Information gives you the same information permanently.
But be warned, it defaults to Sample
merged .
6.3. 3. Options Figure  14. 181. Color Picker Options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Sample Merged
The Sample Merged check-box when enabled will take color
information as a composite from all the visible layers .
Further information regarding Sample Merge is available in
the glossary entry,
Sample Merge .
Sample Average
The Radius slider adjusts the size of
the square area that is used to determine an average color
for the final selection. When you keep clicking the layer, the
mouse pointer shows the size of the square or radius.
Pick Mode Pick Only
The color of the selected pixel will be shown in an
Information Dialog, but not otherwise used.
Set Foreground Color
The Foreground color, as shown in the Toolbox Color
Area, will be set to the color of the pixel you click
on .
Set Background Color
The Background color , as shown in the Toolbox Color
Area, will be set to the color of the pixel you click
on .
Add to Palette
When this option box is checked, the picked color is sent
to the active color palette. See Palette Editor .
Use info window
When this option is checked , the information window is opened
automatically. The Shift key allows you to
toggle this possibility temporarily.
Figure 14.182. Color Picker Info Window 6.2. Paths 6. 4. Zoom
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5. 4. Colorize 5.4. Colorize 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 4. Colorize
The Colorize tool renders the active layer or selection into a greyscale
image seen through a colored glass . You can use it to give a
“ Sepia ” effect to your image. See
Color model for Hue, Saturation, Luminosity.
 5. 4.1. Activating tool
You can get to the Colorize tool in two ways:
In the image-menu through:
Tools → Color Tools → Colorize
or
Colors → Colorize ,
or by clicking the tool icon :
in Toolbox , provided that you have installed color tools in Toolbox.  For this, please refer to Section 1.7, “Toolbox” .
5. 4.2. Options Figure 14.147. Colorize options Presets
You can save the color settings of your image by clicking the
Add settings to favourites button
The
button opens a menu:
Figure 14. 148. Preset Menu
which lets you Import Settings from File or
Export Settings to File ,
and gives you access to the Manage Save Settings dialog:
Figure 14. 149. Manage saved Settings Dialog Select Color Hue :
The slider and the numeric text box allow you to select a hue
in the HSV color circle (0 - 360).
Saturation :
The slider and the input box allows you to select a
saturation: 0 through 100.
Lightness :
The slider and the text box allow you to select a value :
-100 (dark) through 100 (light).
Preview
The Preview button makes all changes dynamically so that they can
be viewed immediately.
5. 3. Hue-Saturation 5.5. Brightness- Contrast
 Report an error in Bugzilla  3. 14. Blur/Sharpen 3.14. Blur/Sharpen 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 14. Blur/Sharpen Figure 14.93. Blur/Sharpen tool icon in the Toolbox
The Blur/Sharpen tool uses the current brush to locally blur or sharpen your
image. Blurring with it can be useful if some element of your image stands
out too much, and you would like to soften it. If you want to blur a whole
layer, or a large part of one, you will probably be better off using one
of the Blur Filters .
The direction of a brushstroke has no effect: if you want directional
blurring, use the Smudge tool.
In “ Sharpen ” mode, the tool works by increasing the contrast
where the brush is applied . A little bit of this may be useful, but
over-application will produce noise. Some of the
Enhancement Filters , particularly
the Unsharp Mask , do a
much cleaner job of sharpening areas of a layer.
Tip
You can create a more sophisticated sharpening brush using the Clone
tool. To do this, start by duplicating the layer you want to work on ,
and run a sharpening filter, such as Unsharp Mask, on the copy. Then
activate the Clone tool, and in its Tool Options set Source to
“ Image source ” and Alignment to “ Registered ” .
Set the Opacity to a modest value, such as 10. Then
Ctrl -click on the copy to make it the source image. If
you now paint on the original layer, you will mix together, where the
brush is applied , the sharpened version with the unsharpened version.
Both blurring and sharpening work incrementally: moving the brush
repeatedly over an area will increase the effect with each additional
pass. The Rate control allows you to determine how quickly the
modifications accumulate. The Opacity control, however, can be used to
limit the amount of blurring that can be produced by a single brushstroke,
regardless of how many passes are made with it.
 3. 14. 1. Activating the Tool
There are different possibilities to activate the tool:
From the image-menu :
Tools → Paint tools → Blur/Sharpen .
The Tool can also be called by clicking the tool icon :
in the Toolbox.  By using the keyboard shortcut
Shift + U .
3.14.2. Key modifiers (Defaults)
See the Paint Tools' Common
Features for a description of key modifiers that have the same
effect on all paint tools.
Ctrl
Holding down the Ctrl key toggles between Blur
and Sharpen
modes; it reverses the setting shown in the Tool Options.
3.14. 3. Options Figure  14. 94. Tool Options for the Blur/Sharpen tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Opacity; Brush; Dynamics; Dynamics Options;
Apply Jitter; Hard Edges
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Convolve Type Blur
mode causes each pixel affected by the brush to be blended with
neighboring pixels, thereby increasing the similarity of pixels
inside the brushstroke area. Sharpen
mode causes each pixel to become more different from its neighbors
than it previously was: it increases contrast inside the
brushstroke area. Too much Sharpen ends in an ugly flocculation
aspect. Whatever setting you choose here, you can reverse
it on-the-fly by holding down the Ctrl key .
“ Convolve ” refers to a mathematical method using
matrices.
Rate
The Rate
slider sets the strength of the Blur/Sharpen effect.
3.13. Perspective Clone 3. 15. Smudge
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4. 4. Crop 4.4. Crop 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 4. Crop Figure 14.115. Crop tool
The Crop Tool is used to crop or clip an image. It works on all the
layers of the image , visible and invisible. This tool is often used
to remove borders, or to eliminate unwanted areas to provide you with a
more focused working area. It is also useful if you need a specific image
size that does not match the original dimensions of your image.
Just like the selection tools, the new crop tool has been enhanced with
the v2.4 release. The resize handles actually resize the crop rectangle
instead of providing both resize and move functionality. The tool behaves
more naturally and consistently with other GIMP tools. To move, simply drag the rectangle clicking within the area. Resizing is
possible in one or two axes at the same time dragging the handle-bars on
the sides and corners. The outside area can be darkened with a nice
passepartout effect to better get the idea of how the final crop will
look like. To validate cropping, click inside the crop rectangle or
press the Enter key .
When the mouse becomes the moving cross-hair, you can use the keyboard
arrow keys to move the crop rectangle. Holding the
Shift key down allows to move by increments of 25 pixels.
You can use Guides to position the crop area. Make sure that the
View → Snap to Guides
option is checked.
Note
You can see the aspect ratio in the status bar:
 4. 4. 1. Activating the Tool
You can activate this tool in different ways:
From the image menu bar
Tools → Transform tools → Crop ,
by clicking the tool icon :
in the ToolBox,
by using the keyboard shortcut
Shift + C . 
4. 4.2. Key modifiers (Defaults)
When you maintain click on the crop rectangle, handles
disappear and
holding down the Ctrl key toggles to the
Extend from Center option,
holding down the Shift key toggles to the
Fixed option, which makes some
dimensions fixed.
4.4. 3. Tool Options Figure  14. 116. Tool Options for the “ Crop ” tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Current Layer Only
This option will make crop affect only the active layer.
Allow Growing
This option allows the crop or resize to take place outside the
image (or layer), and even the canvas. So, you can give the size
you want to the resulting image. Transparency will be used if
there is no material to crop.
Figure 14.117. Example for “ Allow Growing ” An image on a big canvas
The option is checked. The crop rectangle extends outside
the canvas.
The resulting image. Expand from Center
When this option is checked , the crop rectangle expands from
the first pixel you clicked taken for center. You can toggle
this option with Ctrl while drawing the crop
rectangle.
Fixed
You can also access this option by holding down the
Ctrl key while drawing the crop rectangle.
This option offers you several to make drawing
the crop rectangle respect fixed dimensions, or their ratio:
Aspect ratio : That's the default
possibility. Width and Height keep the same ratio they have
in the original image, when drawing the crop rectangle.
Width / Height : Only Width or Height
will remain fixed. The value of this dimension can be set in
the text box below ; it defaults to 100 pixels.
Size : Both Width and Height will be
fixed. Their values can be set in the text box below , in the
form “ 150x100 ” for example. The crop rectangle
will adopt this values as soon as you click the image. On the
right , two buttons let you choose a
Landscape (widthwise) or
Portrait (upright) format for the
crop rectangle.
Position
These two text boxes show the position ( horizontal on the left,
vertical on the right) of the upper left corner of the crop
rectangle in real time and you can change it manually too. It is
stated in pixels, but you can change the unit thanks to the
drop-down list of the px button. The
coordinate origin is the upper left corner of the canvas (not of
the image).
Size
These two text boxes show the size ( horizontal on the left,
vertical on the right) of the crop-rectangle in real time and you
can change it manually too. It is stated in pixels, but you can
change the unit thanks to the drop-down list of the
px button.
Highlight
This option toggles the dark outside area intended for
highlighting the crop rectangle.
Guides
All kinds of guides are described in
Section 2.2, “Rectangle Selection”
Autoshrink
The Auto Shrink button will attempt to locate a border, in the
active layer, from which to draw dimensions from. This option
only works well with isolated objects contrasting sharply with
background.
Figure 14.118. Example for “ Autoshrink ”
An image with a sharp limit in it and a crop rectangle.
After clicking the Autoshrink button, the crop rectangle
has been shrunk to fit the sharp limits.
Shrink Merged
This option works the same, with Auto Shrink or not. It uses the
pixel information from all visible layers,
rather than just from the active layer.
4.3. Move 4.5. Rotate
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5.8. Curves 5.8. Curves 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 8. Curves
The Curves tool is the most sophisticated tool for changing the color,
brightness, contrast or transparency of the active layer or a selection.
While the Levels tool allows you to work on Shadows and Highlights, the
Curves tool allows you to work on any tonal range. It works on RGB
images.
 5. 8. 1. Activating the Tool You can get to this tool in several ways:
In the image menu through
Tools → Color Tools → Curves or
Colors → Curves .
By clicking on the tool icon
in Toolbox , if this tool has been installed there.  For this, please
refer to Section 1.7, “Toolbox” .
5. 8.2. “ Adjust Color Curves ” options Figure 14.168. The “ Adjust Color Curves ” dialog Presets
You can save the color settings of your image by clicking the
Add settings to favourites button
The
button opens a menu:
Figure 14. 169. Preset Menu
which lets you Import Settings from File or
Export Settings to File ,
and gives you access to the Manage Save Settings dialog:
Figure 14. 170. Manage saved Settings Dialog Channel There are five options: Value
The curve represents the Value, i.e. the brightness of
pixels as you can see them in the composite image.
Red; Green; Blue
The curve represents the quantity of color in each of the
three RGB channels. Here, dark means
little of the color.
Light means a lot
of the color.
Alpha
The curve represents the opacity of the pixels.
Dark means
very transparent .
Light means very
opaque . Your image or active layer must have
an Alpha channel for this option to be enabled.
Reset Channel
This button deletes all changes made to the selected channel and
returns to default values.
Linear and Logarithmic buttons
These buttons allow to choose the Linear or Logarithmic type of
the histogram. You can also use the same options in Tool Options
dialog. This grayed out histogram is not displayed by default.
Main Editing Area The horizontal gradient : it represents
the input tonal scale. It, too, ranges from 0 (black) to 255
(white), from Shadows to Highlights. When you
adjust the curve, it splits up into two parts; the upper part
then represents the tonal balance of the
layer or selection.
The vertical gradient : it represents the
destination, the output tonal scale. It ranges from 0 (black)
to 255 (white), from Shadows to Highlights.
The chart : the curve is drawn on a grid
and goes from the bottom left corner to the top right corner.
The pointer x/y position is permanently displayed in the top
left part of the grid. By default, this curve is straight,
because every input level corresponds to the same
ouput tone. GIMP automatically places an anchor at both
ends of the curve, for black (0) and white (255).
If you click on the curve, a new anchor
is created. When the mouse pointer goes over an anchor, it
takes the form of a small hand . You can
click-and-drag the anchor to bend the curve. If you click
outside of the curve, an anchor is also created, and the
curve includes it automatically.
Unactive anchors are black. The active anchor is white. You
can activate an anchor by clicking on it. You can also swap
the anchor activation by using the Left and Right arrow keys
of your keyboard. You can move the anchor vertically with the
Up and Down arrow keys. This allows you to fine tune the
anchor position. Holding the Shift down lets
you move it by increments of 15 pixels.
Two anchors define a curve segment which
represents a tonal range in the layer. You can click-and-drag
this segment (this creates a new anchor). Of course, you
can't drag it beyond the end anchors.
To delete all anchors (apart from both ends), click on the
Reset Channel button. To delete only one
anchor, move beyond any adjacent anchor on horizontal axis.
Meanwhile, on the canvas, the mouse pointer has the form of
an eye-dropper. If you click on a pixel , a vertical line
appears on the chart, positioned to the source value of this
pixel in the selected channel. If you
Shift - click, you create an anchor in the
selected channel. If you Ctrl - click, you
create an anchor in all channels, possibly including the
Alpha channel. You can also Shift -drag and
Ctrl -drag: this
will move the vertical line and the anchor will show up when
releasing the mouse left button.
The histogram of the active layer or selection for the
selected channel is represented grayed out in the chart. It's
only a reference.
Curve type Smooth
This the default mode. It constrains the curve type to a
smooth line with tension. It provides a more realistic
render than the following.
Free Hand
With this mode, you can draw a broken line that you can
smooth by clicking the Curve Type
button again.
Preview
The Preview button makes all changes to the levels dynamically so
that the new level settings can be viewed immediately.
Tool Options dialog
Although this tool is not present in the Toolbox by default ( For this,
please refer to Section 1.7, “Toolbox” if you want to add
it), nevertheless it has a Tool Option Dialog under the Toolbox. These
options are described here:
Histogram Scale
These two options have the same action as the Logarithmic
and Linear
buttons in the Curves dialog.
Sample Average
This slider sets the “ radius ” of the color-picking
area. This area appears as a more or less enlarged square when you
maintain the click on a pixel. Here, the eye-dropper is used to
locate a pixel: radius = 1 seems the best.
5.8.3. Using the “ Curves ” tool 5.8.3.1. Summary and basic shapes
We create anchors and segments on the curve and we move them to
shape the curve. This curve maps “ input ” tones of
the active layer or selection to “ output ” tones.
How the Curves tool works
Moving the anchor of a pixel upwards makes this pixel brighter.
Moving the anchor upwards Making the curve more horizontal Making the curve more horizontal forces all the input tonal range to
occupy a shrunk output tonal range.
The histogram shows the compression of pixels into the output range.
Darkest and brightest pixels disappeared: contrast decreases.
Figure 14.171. Making the curve more horizontal Make the curve more horizontal The resulting histogram Making the curve more vertical
Moving the upper end point to the left and the lower end point to
the right is the same as moving the white slider to the left and the
black slider to the right in the Levels tool: all pixels whose value
is more than the white point (the flat part of the curve) are made
white ( more colored / more opaque according to the selected
channel). All pixels whose value is less than the black point (the
lower flattened curve) are made black (black / completely
transparent). Pixels corresponding to points of the curve that have
moved up are made lighter. Pixels corresponding to points of the
curve that have moved down are made darker (green arrows). All
these pixels will be extended to the whole output tonal range.
The histogram shows the extension of values, from black (0) to White
(255): contrast is increased. Since the Value channel is selected ,
changes affect all color channels and colors increase.
Figure 14.172. Making the curve more vertical Make the curve more vertical Result and its histogram 5.8.3.2. Practical cases Invert colors Inverted curve
Black is made White (fully colored / fully opaque). White is made
black (black, fully transparent). All pixels adopt the complementary
color. Why that? Because subtracting the channel values from 255
gives the complementary color. For example: 19;197;248 a sky blue
gives 255-19; 255-197; 255-248 = 236;58;7, a bright red.
Enhance contrast Contrast enhanced
Contrast is increased in mid tones because the curve is steeper
there. Highlights and Shadows are increased but contrast is slightly
less in these areas because the curve is flatter.
Working on color channels
For every channel, we moved the white point horizontally to the
left, to the first Highlights. This lightens Highlights up. Then we
shaped the curve to lighten Mid tons and Shadows while keeping
black.
The original image and the result 5.7. Levels 5.9. Posterize
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5. 10. Desaturate 5.10. Desaturate 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 10. Desaturate
By using the Desaturate command, you can
convert all of the colors on the active layer to corresponding shades
of gray . This differs from converting the image to grayscale in two
respects. First, it only operates on the active layer and second,
the colors on the layer are still RGB values with three components. This
means that you can paint on the layer, or individual parts of it,
using color at a later time.
Note
This command only works on layers of
RGB images . If the image is in Grayscale or Indexed mode, it can do nothing.
 5. 10. 1. Activating the Command You can get to this tools in several ways:
In the image menu through
Tools → Color Tools → Desaturate or
Colors → Desaturate ,
by clicking on the tool icon
in Toolbox , if this tool has been installed there. For this, please
refer to Section 1.7, “Toolbox” .  5. 10. 2. Options Figure 14.175. The “ Desaturate ” option dialog Three options are available: Choose shade of gray based on Lightness The graylevel will be calculated as
Lightness = ½ × (max(R,G,B) + min(R,G,B))
Luminosity The graylevel will be calculated as
Luminosity = 0.21 × R +
0.72 × G +
0.07 × B
Average The graylevel will be calculated as Average Brightness = (R + G + B) ÷ 3 Figure 14.176. Comparing the three options Original image “ Lightness ” applied “ Luminosity ” applied.
“ Average ” applied.
5.9. Posterize 6. Other
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3. 16. Dodge/Burn 3.16. Dodge/Burn 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 16. Dodge/Burn Figure 14.97. Dodge tool
The Dodge or Burn tool uses the current brush to lighten or darken the
colors in your image. The mode will determine which type of pixels are
affected.
 3. 16. 1. Activating the Tool
There are different possibilities to activate the tool:
From the image-menu :
Tools → Paint Tools → Dodge / Burn .
The Tool can also be called by clicking the tool icon :
,
or by using the
Shift + D
keyboard shortcut. 
3. 16.2. Key modifiers (Defaults) Ctrl
Toggle between dodge or burn types. The type will remain switched
until Ctrl is released.
Shift Shift places the Dodge or Burn tool into
straight line mode. Holding Shift while clicking
Button1 will Dodge or Burn in a
straight line. Consecutive clicks will continue Dodge or
Burn in straight lines that originate from the end of the
last line.
3. 16. 3. Options Figure  14. 98. “ Dodge/Burn ” tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Opacity; Brush; Dynamics; Dynamics Options;
Apply Jitter; Hard Edge See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Type The dodge effect lightens colors. The burn effect darkens colors. Range There are three modes: Shadows
restricts the effect to darkest pixels.
Midtones
restricts the effect to pixels of average tone.
Highlights
restricts the effect to lightest pixels.
Exposure
Exposure defines how much the tool effect will be strong, as a
more or less exposed photograph. Default slider is 50 but can vary
from 0 to 100.
3.15. Smudge 4. Transform Tools
 Report an error in Bugzilla  3. 2. Dynamics 3.2. Dynamics 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Dynamics
The dynamics apply a more “ real feeling ” to the brush by
connecting one or more of the brush parameters to the way of using the
brush. You may for instance let the width of the pencil vary according to
the speed of the stylus or the mouse , make the color saturation
depending on the stylus pressure, make the color changing as the
direction of the brush changes on the canvas, and so on. You may choose
among several presets or define your own. The dynamics are created to be
used together with drawing tablets, but some are available using the mouse.
The dynamics will make some of the behaviors of the drawing tools act more
like the physical ( “ real ” ) tools.
Figure 14.49. Dynamics in Tool Options The Dynamics in Tool Options Dialog The Dynamics Preset List
The Dynamics area in the Tool Option dialog shows from left to right, the
button to open the list containing the available dynamic presets, a field
displaying the name of the current preset, and rightmost the edit button.
Click on the
button to open the dialog window displaying the available dynamics presets
and select another preset.
3.2.1. The Paint Dynamics Selection Dialog Figure 14.50. The Paint Dynamics Selection Dialog
The Paint Dynamics dialog window can be opened
from the image-menu:
Windows → Dockable Dialogs → Paint Dynamics ,
or by clicking on the Open the dynamics
selection
button in the list of dynamics presets.
The Paint Dynamics dialog is a dockable dialog;
please see the section Section 2.3, “Dialogs and Docking” for help on
manipulating it.
From this dialog you can select from all the available presets, just
as from the list of dynamics presets. In addition there are five
buttons:
Edit dynamics: Click on this to edit the selected dynamics.
Create a new dynamics: Do just that.
Duplicate this dynamics: Make a copy of the selected dynamics.
Delete this dynamics: Delete the selected dynamics.
Refresh dynamics: Update the dynamics list.
3.2.2. Editing Paint Dynamics Figure 14.51. Editing Paint Dynamics
The Paint Dynamics Editor can be called from:
the edit button in the Tool Options dialog ,
the Paint Dynamics selection dialog by clicking either the
Edit Dynamics button or the Create
a New Dynamics button.
You select the desired behaviors by clicking in the small squares.
Clicking a second time will unselect the marking.
Note
Pre-installed dynamics are grayed out meaning you are not allowed to
change the settings. To edit the options you have to work on a copy
made from one of the pre-installed dynamics or create a new dynamics.
3.2.3. The Paint Dynamics Matrix
The main part of the edit dialog is a table where you can decide
which brush parameters should be affected by the way you use the stylus
or the mouse . You can enable as many parameters and parameter
combinations you want, but usually the fewer the better.
Each column in the table represents a stylus or mouse action except
the random and the fade functions. All functions works with graphic
tablet. Some of the functions are also available using the mouse. These
functions are marked in the tables. The descriptions are using the
default settings of all functions
Pressure : It allows you to decide which
aspects of the tool's action will be affected by pressing the
stylus against the tablet.
Velocity : (mouse) This is the speed of
the brush.
Direction : (mouse) This is the moving direction
of the brush.
Tilt : The behavior of the function depends
on the tilting of the stylus.
Wheel : The output depends on the rotation of
the stylus or the setting of the wheel on the airbrush pen.
Random : ( mouse) The selected option will
change at random.
Fade : ( mouse) The selected option will be
faded in or out depending on the settings of the fade options in
the Dynamic Options menu of the Tools Option dialog.
Each row shows a brush parameter and seven check-boxes, one for
each action. You connect the parameters to the actions by clicking
the appropriate boxes. Clicking on a selected box will unselect the
connection.
Opacity Pressure : Press harder to make the drawing
less transparent.
Velocity : (mouse) The opacity decreases as
the speed of the stylus increases.
Direction : (mouse) The opacity depends on
the direction of the stylus or the mouse . The effect seems to
have a touch of randomness built in.
Tilt : The opacity depends on the tilt of
the stylus.
Wheel : TO DO
Random : (mouse) The opacity changes at
random in the interval set by the opacity slider in the Tool
Options dialog.
Fade : (mouse) Starting with full transparency
and ending with the opacity set by the opacity slider in the
Tool Options dialog.
Size Pressure : Press harder to make the brush
wider.
Velocity : (mouse) Increasing speed decreases
the width of the brush .
Direction : ( mouse) The size of the brush depends on the moving direction of the stylus or the mouse . The
effect seems to have a touch of randomness built in.
Tilt : The size of the brush depends on the
tilt of the stylus.
Wheel : TODO
Random : ( mouse) The size of the brush changes at random up to the size set in the brush size slider
in the Tool Options dialog.
Fade : (mouse) Fades from a narrow brush to
the size set by the brush size slider in the Tools Options dialog.
Angle
TO DO
Color
By default the color is picked from the foreground color in the
toolbox. However, if the color is activated in the dynamics
editor, the color is instead collected from the active gradient.
Velocity : (mouse) At slow speeds the color
is collected from the right side of the gradient . As the speed
increase the color is picked more and more from the left side
of the gradient .
Direction : (mouse) The direction determine
where on the gradient the color is picked from. The effect seems
to work a bit on random.
Random : (mouse) The color is picked at
random from the gradient.
Fade : (mouse) The start color is collected
from the left side of the gradient and then more and more from
the right side during the stroke. The behavior of the fading is
set in the Fade Options in the Tool Options Dialog.
Hardness
The hardness option is useful only for fuzzy brushes.
Velocity : (mouse) At slow speed the brush
is hard and become more fuzzy as the speed increase.
Random : (mouse) The fussiness of the brush
varies at random.
Fade :(mouse) The brush become less fuzzy
during the stroke. The behavior of the fading is set in the Fade
Options in the Tool Options Dialog.
Force
TO DO
Aspect Ratio
The Aspect Ratio Slider in the Tool Options Dialog must be set
to other values than the default value of 0.00 to activate the
dynamics. If the aspect ratio slider is set to a negative value
the width of the brush will vary while the height of the brush
is constant. If the slider is set to a positive value only the
height of the brush will vary .
Velocity : ( mouse) The aspect
ratio of the brush (width / height) varies with the speed of
the brush.
Direction : ( mouse) The aspect ratio of the
brush varies with the moving direction of the brush. The effect
seems to have a touch of randomness built in.
Random : ( mouse) The aspect ratio of the
brush varies at random.
Fade : (mouse) If the Aspect Ratio Slider
is set to a positive value the brush will fade from full height
at the start of the stroke to the height set by the aspect ratio
slider. If the slider is set to a negative value the brush fades
from full width to the width set by the aspect ratio slider. The
behavior of the fading is set in the Fade Options in the Tool
Options Dialog.
Spacing
Spacing is the distance between the marks set by the brush when
drawing lines. With this option set the spacing is affected by how
the stylus or mouse is used.
Velocity : (mouse) The spacing between the
footprints of the brush increases with increasing speed.
Direction : (mouse) The spacing varies with
the moving direction of the brush. The effect seems to have a
touch of randomness built in.
Random : (mouse) The spacing varies at random.
Fade : (mouse) Starting with a wide spacing
and gradually make the spacing narrower. The behavior of the
fading is set in the Fade Options in the Tool Options Dialog.
Rate
This option applies to the Airbrush, Convolve tool, and
Smudge tool, all of which have time-based effects.
The actions of these tools are more or less quick. The amount
of Rate depends on the setting of the Rate slider in the Tool
Options dialog.
Flow
Significant only for the Airbrush: more or less paint is delivered.
The amount of flow depends on the setting of the Flow slider in the
Tool Options dialog.
Jitter
Normally the brush draws a line by printing the brush marks close
together. Adding jitter means that the brush prints are scattered
along the line. The amount of scattering depends on the setting
of the jitter slider in the Tool Options dialog window.
Pressure : At low pressure the brush prints
are spread according to the value set in the jitter amount
slider. As the pressure increases the scattering amount decreases.
Velocity : (mouse) At slow speed the brush
prints are spread according to the value set in the jitter amount
slider. As the speed increase the scattering amount decrease.
Direction : (mouse) The jitter effect depends
on the direction of the brush . The effect seems to have a touch
of randomness built in.
Random : (mouse)The jitter varies at random.
Fade : (mouse) Starting with no jitter
and ending with the amount of jitter set in the jitter amount
slider. The behavior of the fading is set in the fade options
in the Tool Options dialog.
3.2.4. Customizing the Dynamics Figure 14.52. Customizing the Dynamics
If the current options do not suits you, you may fine-tune the settings
from the Paint Dynamics Editor. Click on the down arrow to open the
drop down menu and then select what option to change.
Figure 14.53. The Fine Tuning Curve
Click on one of the options to open the customizing dialog. The upper
part of the dialog contains a curve where you can adjust the behaviour
of the chosen parameters selected in the lower part of the dialog. You
can drag the curve by pointing on it with the mouse pointer , holding
down the left mouse button and the move the curve wherever you want
inside the diagram.
3.2.5. Dynamics Examples Figure 14.54. Dynamics Options
The brush strokes
The brush size - fade curve
The color - fade curve
The examples shown are very brief, but will perhaps give you an idea
of how to use this functions. Feel free to try other combinations. In
these examples the foreground color is set to blue (#0000ff) and the
background color to yellow (#ffff00). Fading: 200 pixels. Paintbrush
size: 72. All other settings are the default values except for those
values changed
Example 1 shows the result when the brush size is connected to the
fading. Default options. The brush size starts as zero and increase
to the size set in the brush size slider in the Tools Options Dialog.
In example 2 the brush size is still connected to the fade tool,
but the fade curve is set as in image 5 . The brush size starts at
zero, fades up to full size and then fades down to zero again.
The full fade length is set along the x-axis from left to right. The
y-axis determines the size of the brush . At the bottom the brush size
is zero, and at the top of the diagram the brush is set to the full
size according to the size set in the slider in the Brush Options
Dialog. Study the example and the curve to see the relationship.
In example 3 the brush size is disconnected from the fade tool. The
color is connected with the fade option with the curve set as in
image 6. At the start of the drawing the color is picked from the
left side of the gradient , then gradually more from the right side
of the gradient and then finally fading back to the left side again.
As usual the x-axis is the total fade length. When the curve is
near the bottom of the diagram the color is picked from the left
side of the gradient . With the curve at the top of the diagram
the color is picked from the right side of the gradient .
The last example shows a combination of these two settings. Both
the size of the brush and the color are connected to the fading
function with the curves set as in image 5 and 6.
3.2.6. Dynamics Options Figure 14.55. Dynamics Options
Many of the dynamics behaviors also depends on the settings of the
Dynamics Options in the Tool Options dialog and vice versa. For example
the fading will not work if it is not applied in the Dynamics section.
Fade Options
This slider determines the length of the fading. What will
actually happen depends on the setting of the Dynamic. If
set to act on the color for example, the color will be taken from
the current gradient starting from the left side of the gradient
and moving toward the right side of the gradient .
The Fade Options has a drop down list determining how the
fading is repeated.
Figure 14.56.
Illustration of the effects of the three gradient-repeat
options, for the Abstract 2 gradient.
Abstract2 Gradient None Sawtooth Triangular
This option determines what happens if a brush stroke extends
farther than the Length specified by the slider. There are three
possibilities:
None means that the color from the end of
the gradient will be used throughout the remainder of the
stroke;
Sawtooth wave means that the
gradient will be restarted from the beginning, which
will often produce a color discontinuity;
Triangular wave means that the
gradient will be traversed in reverse, afterwards bouncing
back and forth until the end of the brush stroke.
Color Options
Here you can choose the gradient to use as color source
when using the brush with the color option set. Click on the box
showing the gradient to change to another one from the gradient
list.
If no color option is selected in the currently used
dynamics, the brush will use the foreground color set in the
toolbox.
3. Paint Tools 3.3. Brush Tools (Pencil, Paintbrush, Airbrush)
 Report an error in Bugzilla  2. 3. Ellipse Selection 2.3. Ellipse Selection 2. Selection Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 3. Ellipse Selection Figure 14.14. Ellipse Select icon in the Toolbox
The Ellipse Selection tool is designed to select circular and elliptical
regions from an image, with high-quality anti-aliasing if you want it. For
information on selections and how they are used in GIMP see
Selections ;
for information on features common to all selection tools see
Selection Tools .
This tool is also used for rendering a circle or ellipse on an image. To
render a filled ellipse, create an elliptical selection, and then fill it
using the Bucket Fill tool .
To create an elliptical outline, the simplest and most flexible approach
is to create an elliptical selection and then
stroke
it. However, the quality of anti-aliasing with this approach is rather
crude. A higher quality outline can be obtained by creating two elliptical
selections with different sizes, subtracting the inner one from the outer
one; however this is not always easy to get right. The command
Select → Border...
makes it easy.
 2. 3. 1. Activating the tool
You can access the Ellipse Selection Tool in different ways:
From the image menu bar
Tools → Selection Tools → Ellipse Select ;
By clicking on the tool icon
in the ToolBox,
By using the keyboard shortcut E .  2. 3. 2. Key modifiers Note
See Selection Tools for
help with modifier keys that affect all these tools in the same
way. Only effects options that are specific to this tool are explained
here.
Ctrl
Pressing the key after starting your selection, and holding it
down until you are finished, causes your starting point to be used
as the center of the selected ellipse, instead of a corner of the
rectangle that may contain it. Note that if you press the
Ctrl key before
starting to make the selection, the resulting selection will be
subtracted from the existing selection.
Shift
Pressing the Shift key after starting your
selection, and holding it down until you are finished, constrains
the selection to be a circle. Note that if you press the
Shift key before
starting to make the selection, the resulting selection will be
added to the existing selection.
Ctrl + Shift
Pressing both keys combines the two effects, giving you a circular
selection centered on your starting point.
2.3. 3. Tool handling Figure 14. 15. Example of Ellipse Selection.
When this tool is selected the mouse pointer comes with a circle icon
as soon as it is over the image. A drag-and-drop allows you to
get an ellipse (or a circle) within a rectangular box.
When the mouse button is relaxed, a dotted line ( “ marching
ants ” ) outlines the elliptic selection. It's not necessary to
adjust the selection with care; you can resize it easily later.
When the pointer is moving on the canvas, the pointer and selection
aspects change . You can change the size of the selection by using
handles. See
Tool handling within
the rectangular chapter.
2.3.4. Options Figure  14. 16. Tool Options for the Ellipse Select tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Note
See Selection Tools
for help with options that are common to all these tools. Only
options that are specific to this tool are explained here.
Modes; Antialiasing; Feather edges Common select options. All other options
All these options work exactly the same way, they were described
for the rectangular selection already. See for
Section 2. 2.4, “Tool Options” details.
2.2. Rectangle Selection 2. 4. Free Selection (Lasso)  Report an error in Bugzilla 
3.8. Eraser 3.8. Eraser 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 8. Eraser Figure 14.73. Eraser tool icon in the Toolbox
The Eraser is used to remove areas of color from the current layer or from
a selection of this layer. If the Eraser is used on something that does
not support transparency (a selection mask channel, a layer mask, or the
Background layer if it lacks an alpha channel), then erasing will show the
background color, as displayed in the Color Area of the Toolbox (in case
of a mask, the selection will be modified). Otherwise, erasing will
produce either partial or full transparency, depending on the settings for
the tool options. You can learn more on how to add an alpha channel to a
layer in Section 7.33, “Add Alpha Channel” .
Figure 14.74. Eraser and Alpha channel
The Background Color is White. The image has no Alpha channel. The
Eraser (Opacity 100%) shows the BG color.
The image has an Alpha channel . The Eraser shows transparency.
If you need to erase some group of pixels completely, leaving no trace
behind of their previous contents, you should check the "Hard edge" box in
the Tool Options. Otherwise, sub-pixel brush placement will cause partial
erasure at the edges of the brush-stroke , even if you use a hard-edged
brush.
Tip
If you use GIMP with a tablet, you may find it convenient to treat the
reverse end of the stylus as an eraser. To make this work, all you need
to do is click the reverse end on the Eraser tool in the Toolbox.
Because each end of the stylus is treated as a separate input device,
and each input device has its own separate tool assignment, the reverse
end will then continue to function as an Eraser as long as you don't
select a different tool with it.
 3.8. 1. Activating the tool You can activate this tool in several ways :
From the image menu through
Tools → Paint Tools → Eraser ;
from the Toolbox by clicking on the tool icon
;
or from the keyboard using the shortcut
Shift + E .  3.8.2. Key modifiers
See the Section 3.1, “Common Features” for a description of key
modifiers that have the same effect on all paint tools.
Ctrl
For the Eraser, holding down the Ctrl key puts it
into “ color picker ” mode, so that it selects the
color of any pixel it is clicked on. Unlike other brush tools,
however, the Eraser sets the background
color rather than the foreground color. This is more useful,
because on drawables that don't support transparency, erasing
replaces the erased areas with the current background color .
Alt
For the Eraser, holding down the Alt key switches
it into “ anti-erase ” mode, as described below in the
Tool Options section. Note that on some systems, the
Alt key is trapped by the Window Manager . If this
happens to you, you may be able to use
Alt + Shift
instead.
3.8. 3. Tool Options Figure  14. 75. Tool Options for the Eraser tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Brush; Size; Brush Dynamics; Dynamic Options; Apply Jitter; Incremental
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Opacity
The Opacity slider, in spite of its name,
in this tool determines the “ strength ” of the tool.
Thus, when you erase on a layer with an alpha channel, the higher
the opacity you use, the more transparency you get!
Hard Edge
This option avoids partial erasure at the edges of the
brush-stroke . See above.
Anti Erase
The Anti Erase option of the Erase tool can un-erase areas of an
image, even if they are completely transparent. This feature only
works when used on layers with an alpha channel. In addition to
the check- button in the Tool Options, it can also be activated on-the-fly by holding down the Alt key (or, if
the Alt key is trapped by the Window Manager , by
holding down
Alt + Shift ).
Note
To understand how anti-erasing is possible, you should realize
that erasing (or cutting, for that matter) only affects the
alpha channel, not the RGB channels that contain the image data.
Even if the result is completely transparent, the RGB data is
still there, you simply can't see it. Anti-erasing increases the
alpha value so that you can see the RGB data once again.
Tip
You can use the Eraser tool to change the shape of a floating
selection. By erasing, you can trim the edges of the selection .
3.7. Paintbrush 3.9. Airbrush
 Report an error in Bugzilla  4. 9. Flip 4.9. Flip 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 9. Flip Figure 14.133. Flip tool
The Flip tool provides the ability to flip layers or selections either
horizontally or vertically. When a selection is flipped, a new layer with
a Floating Selection is created. You can use this tool to create
reflections.
 4. 9. 1. Activating the Tool
You can access the Flip Tool in different ways:
From the image menu bar
Tools /
Transform Tools
Flip ,
By clicking the tool icon :
in Toolbox ,
by using the
Shift + F key
combination. 
4. 9. 2. Key modifiers (Defaults) Ctrl Ctrl lets you change the modes between
horizontal and vertical flipping.
4. 9. 3. Options Figure  14. 134. “ Flip Tool ” Options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Affect Note
These options are described in
Transform tools common options .
Flip Type
The Tool Toggle settings control flipping in either a Horizontal
or Vertical direction. This toggle can also be switched using a
key modifier.
4.8. Perspective 4.10. The Cage Tool  Report an error in Bugzilla  2.8. Foreground Select 2.8. Foreground Select 2. Selection Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 8. Foreground Select Figure 14.30. The “ Foreground Select ” tool in the Toolbox
This tool lets you extract the foreground from the active layer or from a
selection . It is based on the SIOX method (Simple Interactive Object
Extraction). You can visit its Web page at
[ SIOX ] .
2.8.1. Directions for use
The creation of a selection with this tool works in a couple of steps:
Roughly select the foreground you want
to extract. When you select this tool, the mouse pointer goes with
the lasso icon. It actually works like the Fuzzy Select tool .
Select as little as possible from the background.
As soon as you release the mouse button, the non selected part of
the image is covered with a dark blue mask. If the selection is not
closed, its ends will be linked automatically together by a straight
line. The mouse pointer goes now with the Paint-brush icon for the
next step.
Figure 14.31. The foreground is roughly selected Draw a line through the foreground : using the
paintbrush, whose size can be changed in options, draw a continuous
line in the selected foreground going over colors which will be
kept for the extraction. The color used to draw the line is of no
importance; not using the same color as foreground is better. Be
careful not painting background pixels.
Figure 14.32. The line drawn on the foreground
In this example, it is important that the line goes over the
yellow capitulum of the flower.
When you release the mouse button , all non-selected areas are in
dark:
Figure 14.33. The area which will be selected
You still have to press the Enter key to get the
wanted selection:
Figure 14.34. Foreground is selected Note
Until you press Enter , you can't undo this selection
by
Ctrl + Z nor by
Select → None ,
and the Undo History is not concerned. To delete this selection, you
must select another tool.
2.8. 2. Activating the Tool
You can activate the Foreground Select tool in two ways:
by clicking on the tool icon
in the Toolbox,
through
Tools → Selection Tools → Foreground Select
in the image menu .
This tool has no shortcut, but you can set one using
Edit → Preferences → Interface → Configure Keyboard Shortcuts → Tools → Foreground Select
2.8. 3. Key modifiers (Defaults) Ctrl
By pressing the Ctrl key , you can switching
between foreground and background selection painting.
2.8.4. Options Figure  14. 35. “ Foreground Select ” tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Antialiasing; Feather edges Note
See Selection Tools
for help with options that are common to all these tools. Only
options that are specific to this tool are explained here.
Contiguous
If this option is enabled , only the area contiguous to the stroke
will be selected. Otherwise all the areas with same colors will be
selected.
Figure 14.36. “ Contiguous ” option effect
Two separated areas with the same color. On the left, only
the left area is marked.
The Contiguous option is checked: only the area close to the
painted line is selected.
The Contiguous option is not checked: both areas, although
they are separated, are selected.
Interactive refinement
Here are some options to work more precisely on your selection:
Mark foreground
default option. The foreground color of the Toolbox is used
to paint. Colors covered by the painted line will be used
for extraction.
Mark background
You can access this option either by clicking on the radio
button or, more simply, by pressing the Ctrl
key . The mouse pointer goes with a small eraser icon. The used color is the background color of
Toolbox.
The pixels of the selection which have the same color as the
“ erased ” pixels will NOT be extracted.
Small brush / Large brush
This slider lets you adapt the size of the brush used to
paint the line. A small brush fits well thin details.
Smoothing
Smaller values give a more accurate selection border but may
introduce holes in the selection.
Preview color
You can select between Red, Green and Blue to mask the image
background.
Color Sensitivity
This option uses the
L*a*b color model. If your
image contains many pixels of the same color in different tones,
you can increase the sensibility of the selection for this
color.
2.7. Intelligent Scissors 3. Paint Tools
 Report an error in Bugzilla  2. 4. Free Selection (Lasso) 2. 4. Free Selection (Lasso) 2. Selection Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 4. Free Selection (Lasso) Figure 14.17. Free Selection icon in the Toolbox
The Free Selection tool, or Lasso, lets you create a selection by drawing
it free-hand with the pointer, while holding down the left mouse button
(or, for a stylus, pressing it against the tablet). When you release the
mouse button , the selection is closed by connecting the current pointer
location to the start location with a straight line. You can go outside
the edge of the image display and come back in if you want to. The Lasso
is often a good tool to use for “ roughing in ” a selection;
it is not so good for precise definition. Experienced users find that
it is often convenient to begin with the lasso tool, but then switch to
QuickMask mode for detail work.
For information on selections and how
they are used in GIMP see
Selections . For
information on features common to all selection tools see
Selection Tools .
Note
The Free Selection tool is much easier to use with a tablet than
with a mouse.
A new possibility came up with GIMP-2.6: the polygonal selection.
Instead of click-and-dragging to draw a free hand selection, you can
click only. This creates an anchor point. Then moving the mouse pointer
draws a line with a new anchor point that you can move as long as you
don't click again ( the mouse pointer comes with the moving cross).
Clicking again anchors this point and creates a segment. By pressing
the Ctrl keyboard key while moving the mouse pointer
contrains moving angles to 15°.
So, you can mix free hand segments and polygonal segments .
Figure 14.18. Mixing free hand segments and polygonal segments  2. 4. 1. Activating the tool
You can access the Lasso Tool in different ways:
From the image menu bar
Tools → Selection Tools → Free Select ,
by clicking on the tool icon
in the ToolBox,
by using the keyboard shortcut F . 
2. 4.2. Key modifiers
The Free Select tool does not have any special key modifiers,
only the ones that affect all selection tools in the same way.
See Selection Tools for
help with these.
2. 4.3. Tool handling
To move the selection, see
Moving selections .
Figure 14.19. Rough selection with the Free Selection tool. 2.4.4. Options Figure  14. 20. Tool Options for the Lasso tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  The Free Select tool has no special tool options,
only the ones that affect all selection tools in the same way.
See Selection Tools for
help with these.
2.3. Ellipse Selection 2.5. Fuzzy selection (Magic wand)  Report an error in Bugzilla  2.5. Fuzzy selection (Magic wand) 2. 5. Fuzzy selection (Magic wand) 2. Selection Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 5. Fuzzy selection (Magic wand) Figure 14.21. Magic Wand tool icon in the Toolbox
The Fuzzy Select (Magic Wand) tool is designed to select areas of the
current layer or image based on color similarity.
When using this tool, it is very important to pick the right starting
point. If you select the wrong spot, you might get something very
different from what you want, or even the opposite.
The Wand is a good tool for selecting objects with sharp edges. It is fun
to use, so beginners often start out using it a lot. You will probably
find, however, that the more you use it, the more frustrated you become
with the difficulty of selecting exactly what you want, no more, no less.
More experienced users find that the
Path and
Color Select
tools are often more efficient, and use the Wand less. Still, it is useful
for selecting an area within a contour, or touching up imperfect
selections. It often works very well for selecting a solid-colored (or nearly
solid-colored) background area.
Note that as the selected area expands outward from the center, it does
not only propagate to pixels that touch each other: it is capable of
jumping over small gaps, depending on Threshold option.
To increase/decrease Threshold, during the use of Fuzzy Selection, after the
first button-press, dragging the pointer downward (or to the right ) or
upward (or to the left ).
 2. 5. 1. Activating the tool
You can access the Magic Wand Tool in different ways:
From the image menu bar
Tools → Selection Tools → Fuzzy Select ,
by clicking on the tool icon
in the ToolBox,
by using the keyboard shortcut U . 
2. 5. 2. Key modifiers (Defaults)
The Fuzzy Select tool does not have any special key modifiers, only the
ones that affect all selection tools in the same way. See
Section 2.1, “Common Features” for help with these.
2.5. 3. Tool handling Figure 14. 22.
Using Magic Wand tool: selected pixels are contiguous
It starts selecting when you click at a spot in the image, and expands
outwards like water flooding low-lying areas, selecting contiguous
pixels whose colors are similar to the starting pixel. You can control
the threshold of similarity by dragging the mouse downward or to the
right: the farther you drag it, the larger you get the selected region.
And you can reduce the selection by dragging upwards or to the left.
To move the selection see
Moving selections .
2. 5.4. Options Figure  14. 23. Tool Options for the Magic Wand tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Note
See Selection Tools
for help with options that are common to all these tools. Only
options that are specific to this tool are explained here.
Mode; Antialiasing; Feather edges
Common select options. Finding Similar Colors
These options affect the way the Magic Wand expands the selection
out from the initial point.
Select Transparent Areas
This option gives the Magic Wand the ability to select areas
that are completely transparent. If this option is not
checked, transparent areas will never be included in the
selection.
Sample Merged
This option becomes relevant when you have several layers in
your image, and the active layer is either semi-transparent
or is set to another Layer Mode than Normal. If this is the
case, the colors present in the layer will be different from
the colors in the composite image. If the
“ Sample Merged ”
option is unchecked, the wand will only react to the color
in the active layer when it creates a selection. If it is
checked it will react to the composite color of all visible
layers. For further information, see the glossary entry
Sample Merged .
Threshold
This slider determines the range of colors that will be
selected at the moment you click the pointer on the initial
point, before dragging it: the higher the threshold, the
larger the resulting selection. After the first
button-press, dragging the pointer downward or to the right
will increase the size of the selection ; dragging upward or
to the left will decrease it. Thus, you have the same set of
possibilities regardless of the Threshold setting: what
differs is the amount of dragging you have to do to get the
result you want .
Selection by
With this option you can choose which component of the image
GIMP shall use to calculate the similarity .
The components you can choose from are
Red ,
Green ,
Blue ,
Hue ,
Saturation and
Value .
2.4. Free Selection (Lasso) 2. 6. Select By Color
 Report an error in Bugzilla  6. 7. GEGL Operation 6.7. GEGL Operation 6. Other  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 7. GEGL Operation Figure 14.193. GEGL Operation tool GEGL ( “ Generic Graphical Library ” ) is a
graph based image processing library designed to handle various image
processing tasks needed in GIMP .
The GEGL Operation tool has been added in GIMP 2.6
and was originally meant as an useful experimental tool for
GIMP developers. The GEGL Operation
tool enables applying GEGL operations to the image and
gives on-canvas previews of the results.
Warning GEGL is in a very early phase and still under
construction.
The GEGL Operation tool is experimental .
6. 7. 1. Activating the Tool
You can get to this tool only from the image menu:
Tools → GEGL Operation .
Tip
In addition to this tool for performing special
GEGL operations you can configure
GIMP to use
GEGL for all color operations.
6. 7.2. Options Figure 14. 194. GEGL Operation tool options GEGL Operation tool with no operation selected. Operation
Click on this button to select the operation you want to apply to
the active selection or, if there is no selection , to the active
layer.
Some of these operations are very basic operations like
“ color ” which fills the active selection or layer
with the specified color, while operations like
“ fractal-explorer ” produce fairly complex patterns
— just like a rendering
filter .
Remember that this is an experimental tool, so some operations may
not work or even crash GIMP . As a consquence,
it doesn't make sense to describe the operations here as long as
the GEGL Operation tool is experimental
Operation Settings
The operation settings depend on the selected
Operation :
Figure 14.195. “ Operation Settings ” example
GEGL operation “ Gaussian Blur ” selected.
If the options of the selected GEGL operation
are not self-explanatory (guess what's the purpose of the
“ color ” operation's “ Color ” option)
you can look for a corresponding non- GEGL tool.
For example, the Fractal
Explorer filter may have the same or similar options as the
“ fractal-explorer ” operation.
Or you can make use of the nice realtime preview feature and just
experiment with different settings.
Preview
If this options is checked, as it is by default, you will get an
on-canvas preview of the selected operation as soon as the
operation in finished. You will have to press the
OK button to actually apply the operation
to the image.
The tool buttons Reset
Pressing this button resets the operation settings the to their
defaults.
Cancel
Clicking on this button aborts the GEGL
operation tool and leaves your image untouched. This is equivalent
to close the dialog window using the usual
Close button provided by your window
manager.
OK
You have to press this button to apply the selected operation to
the image. Then the dialog window will be closed.
6.6. Text Chapter 15. Dialogs
 Report an error in Bugzilla  3. 12. Heal 3.12. Heal 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 12. Heal Figure 14.87. The “ Heal tool ” in the Toolbox
This tool was once described as “ The healing brush looks like a
smart clone tool on steroids ” . And indeed the Healing Tool is a
close relative to the Clone Tool, but it is more smart to remove small
failures in images. A typical usage is the removal of wrinkles in
photographs. To do so, pixels are not simply copied from source to
destination, but the area around the destination is taken into account
before cloning is applied. The algorithm used for this, is described in
a scientific paper by Todor Georgiev
[ GEORGIEV01 ] .
To use it, first choose a brush with a size adapted to the defect. Then
Ctrl -click on the area you want to reproduce. Release the
Ctrl key and drag the sample to the defect. Click. If the
defect is slight, not very
different from its surrounding, it will be corrected as soon. Else, you
can correct it with repeated clicks, but with a risk of daubing
 3. 12. 1. Activating the Tool
There are different possibilities to activate the tool:
From the image-menu :
Tools → Paint tools → Heal ,
or by clicking the tool icon :
in the Toolbox,
or by clicking on the H keyboard shortcut. 
3. 12.2. Key modifiers (Defaults) Ctrl
The Ctrl key is used to select the source .
You can heal from any layer of any image, by clicking on the
image display, with the Ctrl key held down,
while the layer is active (as shown in the
Layers dialog). If Alignment is set to “ Non-aligned ”
or “ Aligned ” in Tool Options, then the point you
click on becomes the origin for healing: the image data at that
point will be used when you first begin painting with the Heal
tool. In source-selection mode, the cursor changes to a
crosshair-symbol.
Shift
Once the source is set, if you press this key, you will see a
thin line connecting the previously clicked point with the current
pointer location. If you click again, while going on holding
the Shift key down , the tool will
“ heal ” along this line.
3.12. 3. Options Figure  14. 88. Heal Tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity ; Brush; Dynamics; Dynamics Options; Apply Jitter; Smoot
Stroke; Hard Edge
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Sample merged
If you enable this option, healing is not calculated only
from the values of the active layer , but from all visible layers.
Alignment
This option is described in Clone
tool .
3.12.4. Healing is not cloning
Although the Heal tool has common features with the Clone tool on using,
the result is quite different.
Figure 14.89. Comparing “ Clone ” and “ Heal ”
Two black spots in the red area. Zoom x800. The source is where the
four colors meet. Cloning on the left spot. Healing on the right
spot.
3.11. Clone 3.13. Perspective Clone  Report an error in Bugzilla  5. 3. Hue-Saturation 5.3. Hue-Saturation 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 3. Hue-Saturation
The Hue-Saturation tool is used to adjust hue, saturation and lightness
levels on a range of color weights for the selected area or active layer.
 5. 3. 1. Activating the Tool You can get to the Hue-Saturation tool in two ways :
In the image-menu through:
Tools → Color Tools → Hue-Saturation , or
Colors → Hue-Saturation
By clicking the tool icon :
in Toolbox , provided that you have installed color tools in Toolbox.  For this, please refer to Section 1.7, “Toolbox” .
5. 3.2. Options Figure 14.143. Hue-Saturation tool options Presets
You can save the color settings of your image by clicking the
Add settings to favourites button
The
button opens a menu:
Figure 14. 144. Preset Menu
which lets you Import Settings from File or
Export Settings to File ,
and gives you access to the Manage Save Settings dialog:
Figure 14. 145. Manage saved Settings Dialog Select Primary Color to Adjust
You can choose, between six, the three primary colors ( Red,
Green and Blue) and the three complementary colors (Cyan,
Magenta and Yellow), the color to be modified. They are
arranged according to the color circle. When hue increases, hue
goes counter-clockwise. When it decreases, it goes clockwise. If
you click on the Master button, all colors
will be concerned with changes. GIMP standard is to set Red as 0.
Note that this colors refer to color ranges and not to color
channels.
Hue changes are shown in color swatches and the result is visible
in the image if the “ Preview ” option is enabled.
Overlap
This slider lets you set how much color ranges will overlap. This
effect is very subtle and works on very next colors only:
Figure 14.146.
Example for the “ Overlap ” option
Original image . From the
left to the right: a reddish yellow (255;240;0); a pure
yellow (255;255;0); a greenish yellow (240;255;0).
Overlap = 0 . Hue = 15.
Colors become ( 186;255;1), (168;255;1), (156;255;1).
Overlap = 100 . Hue = 15.
Colors become ( 192;255;1), (168;255;1), (162;255;1).
Because of overlap, greenish is less green and reddish is
less red.
Adjust Selected Color Hue :
The slider and the input box allow you to select a hue in
the color circle (-180, 180).
Lightness :
The slider and the input box allow you to select a value
(luminosity): -100, 100.
Note
Lightness changes here concern a color range, while they
concern a color tone with Curves and Levels tools, which
work on color channels. If you change the Yellow lightness
with Hue-Saturation, all yellow pixels will be changed,
while only dark, bright or medium pixels luminosity will
be changed with Curves or Levels tools.
Saturation :
The slider and the input box allow you to select a
saturation: -100, 100.
The Initialize Color
button deletes changes to hue, lightness and saturation of the
selected color.
Preview
The Preview button makes all changes dynamically so that they can
be viewed straight away.
5. 2. Color Balance 5. 4. Colorize
 Report an error in Bugzilla  3. 10. Ink 3.10. Ink 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 10. Ink Figure 14.78. The “ Ink ” tool in Toolbox
The Ink tool uses a simulation of an ink pen with a controllable nib to
paint solid brush strokes with an antialiased edge. The size, shape and
angle of the nib can be set to determine how the strokes will be rendered.
 3. 10. 1. Activating the Tool You can find the Ink tool in several ways :
In the image-menu through:
Tools → Paint Tools → Ink .
By clicking on the tool icon :
in Toolbox ,
or by using the K keyboard shortcut. 
3. 10. 2. Key modifiers (Defaults) Ctrl
This key changes the nib to a
Color Picker .
3.10. 3. Options Figure  14. 79. Ink Tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Adjustment Size
Controls the apparent width of the pen's nib with values
that ranges from 0 (very thin) to 20 (very thick).
Angle
This controls the apparent angle of the pen's nib relative
to horizontal.
Sensitivity Size
This controls the size of the nib, from minimum to maximum.
Note that a size of 0 does not result in a nib of size zero,
but rather a nib of minimum size.
Tilt
Controls the apparent tilt of the nib relative to
horizontal. This control and the Angle control described
above are interrelated. Experimentation is the best means of
learning how to use them.
Speed
This controls the effective size of the nib as a function of
drawing speed. That is, as with a physical pen, the faster
you draw, the narrower the line.
Type and Shape Type
There are three nib shapes to choose from: circle, square,
and diamond.
Shape
The geometry of the nib type can be adjusted by holding
button 1 of the mouse on the small square at the center of
the Shape icon and moving it around.
3.9. Airbrush 3.11. Clone
 Report an error in Bugzilla 
2. 7. Intelligent Scissors 2. 7. Intelligent Scissors 2. Selection Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 7. Intelligent Scissors Figure 14.27. Intelligent Scissors tool icon in the Toolbox
The Intelligent Scissors tool is an interesting piece of equipment: it has
some features in common with the Lasso, some features in common with the
Path tool, and some features all its own. It is useful when you are trying
to select a region defined by strong color-changes at the edges. To use
the Scissors, you click to create a set of "control nodes", also referred to
as anchors or control points, at the edges of
the region you are trying to select . The tool produces a continuous curve
passing through these control nodes, following any high-contrast edges it
can find. If you are lucky, the path that the tool finds will correspond
to the contour you are trying to select .
Unfortunately, there seem to be some problems with the edge-following
logic for this tool, with the result that the selections it creates tend
to be pretty crude in a lot of cases. A good way to clean them up is to
switch to QuickMask
mode, and use paint tools to paint in the problematic parts. On the whole,
most people find the Path tool to be more useful than the Scissors,
because, even though it does not have the intelligent edge-finding
capability, the paths it produces persist until you delete them, and can
be altered at any time.
 2. 7. 1. Activating the tool
You can access the Intelligent Scissors Tool in different ways:
From the image menu bar
Tools → Selection Tools → Intelligent Scissors ,
by clicking on the tool icon
in the ToolBox,
by using the keyboard shortcut I  .
2. 7.2. Key modifiers
The default behavior of the Shift ,
Ctrl , and Alt keys is described in
Section 2. 1.1, “Key modifiers (Defaults)” for all selection tools.
There is, however, one key modifier that has a special behavior if you
use it while editing a selection, that is after you
have added the first node:
Shift
By default, the auto-edge snap feature is
enabled: whenever you click and drag the mouse pointer , the
Scissors tool finds the point of the maximal gradient (where the
color change is maximal) for placing a new control node or moving
an existing node.
Holding down this key while clicking and dragging disables this
feature, and the control node will be placed at the position of
the mouse pointer .
2.7. 3. Tool handling Figure 14. 28. Using Intelligent Scissors
Each time you left-click with the mouse, you create a new control point,
which is connected to the last control point by a curve that tries to
follow edges in the image. To finish, click on the first point (the
cursor changes to indicate when you are in the right spot). You can
adjust the curve by dragging the control nodes, or by clicking to create
new control nodes. When you are satisfied, click anywhere inside the
curve to convert it into a selection.
As said above when you click with this tool you drop points. The
selection boundary is driven by these control points. During creation you
can move each one by clicking and dragging, except the first and the last
one. The selection is closed when you are clicking the last point over
the first one. When the selection is closed the pointer shape
changes according to its position: inside
,
on the boundary
,
and outside
.
You can adjust the selection creating new points by clicking on the
boundary or by moving each control points (merged first and last
point). The selection is validated when you click inside.
You have to notice that you can get only one selection; if you
create a second selection, the first one is erased when you validate the
second one.
Warning
Be sure not to click inside the curve until you are completely done
adjusting it. Once you have converted it into a selection, undoing
takes you back to zero, and you will have to start constructing the
curve again from scratch if you need to change it. Also be sure not to
switch to a different tool, or again all of your carefully created
control nodes will be lost. (But you still can transform your
selection into a path and work it with the Path tool.)
To move the selection, see
Moving selections .
2. 7.4. Options Figure  14. 29. Tool Options for the Intelligent Scissors
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Modes; Antialiasing; Feather edges Note
See Selection Tools
for help with options that are common to all these tools. Only
options that are specific to this tool are explained here.
Interactive boundary
If this option is enabled , dragging a control node during
placement will indicate the path that will be taken by the
selection boundary. If it is not enabled, the node will be shown
connected to the previous node by a straight line while you are
dragging it around, and you won't see the resulting path until you
release the pointer button. On slow systems, if your control nodes
are far apart, this may give a bit of a speed-up.
2.6. Select By Color 2.8. Foreground Select
 Report an error in Bugzilla  5. 7. Levels 5.7. Levels 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 7. Levels
The Level tool provides features similar to the
Histogram dialog but can also
change the intensity range of the active layer or selection in every
channel. This tool is used to make an image lighter or darker, to change
contrast or to correct a predominant color cast.
5. 7. 1. Activating the Tool You can get to this tools in several ways:
In the image menu through
Tools → Color Tools → Levels .
In the image menu through
Colors → Levels .
By clicking on the tool icon
in the toolbox if this tool has been installed there. For this, please
refer to Section 1.7, “Toolbox” .
5. 7.2. Options Figure 14. 160. Level tool options Presets
You can save the color settings of your image by clicking the
Add settings to favourites button
The
button opens a menu:
Figure 14. 161. Preset Menu
which lets you Import Settings from File or
Export Settings to File ,
and gives you access to the Manage Save Settings dialog:
Figure 14. 162. Manage saved Settings Dialog Channel
You can select the specific channel which will be modified by the
tool:
Value makes changes to the value of
all RGB channels in the image: the image becomes darker or
lighter.
Red , Green and
Blue work on a particular color
channel: the image gets more or less color. Remember that
adding or removing a color result in removing or adding
the complementary color
Alpha works on semi-transparent layers
or selections: here, dark means more transparency, and
white is fully opaque. Your image must have an Alpha
Channel, otherwise this option is disabled.
Initialize channel cancels changes to
the selected channel.
Input Levels
The main area is a graphic representation of the active layer or
selection dark (Shadows), mid and light (Highlight)tones content
(the Histogram). They are on abscissa from level 0 (black) to
level 255 (white). Pixel number for a level is
on ordinate axis. The curve surface represents all the pixels of
the image for the selected channel. A well balanced image is an
image with levels (tones) distributed all over the whole range.
An image with a blue predominant color, for example, will produce
a histogram shifted to the left in Green and Red channels,
signified by green and red lacking on highlights.
Level ranges can be modified in three ways:
Three triangles as sliders: one black for dark tones
(Shadows), one grey for midtones (Gamma), one white for light
(Highlights) tones.
The black slider determines the black point
: all pixels with this value or less
will be black (no color with a color channel selected /
transparent with the Alpha channel selected).
The white slider determines the white point
: all pixels with this value or
higher, will be white (fully colored with a color channel
selected / fully opaque with the Alpha channel selected).
The gray slider determines the mid point .
Going to the left, to the black, makes the image lighter
( more colored / more opaque ) . Going to the right, to the
white, makes the image darker (less colored / more
transparent).
Two eye-droppers: when you click them, the mouse pointer
becomes an eye-dropper. Then clicking on the image determines
the black or the white point according to the chosen
eye-dropper. Use the left, dark one
to determine the black-point; use the right, white one
to determine the white point.
Three numeric text boxes to enter values directly.
Input Levels are used to lighten highlights (bright tones),
darken shadows (dark tones), change the balance of bright and
dark tones. Move sliders to the left to increase lightness
(increase the chosen color / increase opacity). Move the sliders
to the right to lessen lightness (lessen the chosen color /
lessen opacity).
Examples for Input Levels
The original image is a gray-scaled image with three stripes:
Shadows (64), Mid Tones (127), Highlights (192). The histogram
shows three peaks, one for each of the three tones.
Original image
The Value channel is selected . The black slider (Shadows) has
been moved up to the Shadows peak. The 64 value became 0 and
the Shadows stripe became black (0). The Gamma (mid tones)
slider is automatically moved to the middle of the tone range.
Mid tones are made darker to 84 and Highlights to 171.
Black slider has been moved
The white slider (highlights) has been moved up to the
highlight peak. The 192 value became 255 and the highlight
stripe became white. The Gamma (mid tones) slider is
automatically moved to the middle of the tone range. Mid tones
are made lighter to 169 and Shadows to 84.
White slider has been moved Output Levels
Output levels allows manual selection of a constrained output
level range. There are also numeric text boxes with arrow-heads
located here that can be used to interactively change the Output
Levels.
Output levels force the tone range to fit the new limits you have
set.
Working with Value: values are compressed and look more
alike; so contrast is reduced. Shadows are made lighter:
new details can show up but contrast is less; a compromise
is necessary. Highlights are made darker.
Working with Color channels: if you the use the green
channel for example and set the output levels between 100
and 140, all pixels with some green, even a low value, will
have their green channel value shifted between 100 and 140.
Working with Alpha channel: all Alpha values will be
shifted to the range you have set.
Example for Output Levels
The original image is a RGB gradient from black (0;0;0) to
white (255;255;255). Output Levels has no histogram; here, we
used
Windows → Dockable Dialogs → Histogram .
Original image (a gradient)
Value channel selected. The black slider has been moved to 63
and the white slider to 189. The Histogram shows the
compression of pixels . No pixel is less than 63, and no pixel
is more than 189. In the image, Shadows are lighter and
Highlights are darker: contrast is reduced.
Black slider has been moved All Channels Auto : Performs an automatic setting
of the levels.
Three eyedroppers
,
,
.
.
These three buttons
respectively represent a white, a gray and a black eye-dropper.
When you click one of these buttons, the mouse pointer takes the
form of the eye-dropper it represents. Then, when clicking the
image, the clicked pixel determines the white point
, the black point or the
mid point according to the eye-dropper you
chose. Works on all channels, even if a particular channel is
selected.
Figure 14.163. Example for Levels eye-droppers
Above is original gradient from black to white. Below is the
result after clicking with the white eye-dropper: all
pixels with a value higher than that of the clicked pixel
turned to white.
Edit these settings as Curves
To make your work easier, this button lets you turn to the
Curves tool with the same
settings.
Preview
The Preview button makes all changes to the levels dynamically so
that the new level settings can be viewed straight away.
5. 7.3. Tool Options dialog
Figure 14.164. “ Levels ” tool options
Although this tool is not present in the Toolbox by default ( please
refer to Section 1.7, “Toolbox” if you want to add it),
nevertheless it has a Tool Option Dialog under the Toolbox. These
options are described here:
Histogram Scale
These two options have the same action as the Logarithmic
and Linear
buttons in the Levels dialog.
Sample Average
This slider sets the “ radius ” of the color-picking
area. This area appears as a more or less enlarged square when
you maintain the click on a pixel.
5.7.4. Actual practice Figure 14.165. A very under-exposed image Original image
The histogram shows a predominance of Shadows and missing
Highlights.
Figure 14.166. Setting the white point
The white slider has been moved to the start of well marked
Highlights. The image lightens up.
The resulting histogram (down) shows Highlights now, but Shadows
are still predominant.
Figure 14.167. Setting the balance between Shadows and Highlights
The mid slider has been moved to the left. This results in
reducing the proportion of Shadows and increasing the proportion
of Highlights.
The resulting histogram (down) confirms the reduction of Shadows.
5.6. Threshold 5.8. Curves
 Report an error in Bugzilla 
6. 5. Measure 6.5. Measure 6. Other  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 5. Measure Figure 14.185. Measure tool
The Measure Tool is used to gain knowledge about pixel distances in your
working image. By clicking and holding the mouse button, you can determine
the angle and number of pixels between the point of click and where the
mouse pointer is located. The information is displayed on the status bar
or can also be displayed in the Info Window.
When you pass the mouse pointer over the end point it turns to a move
pointer. Then if you click you can resume the measure.
6.5.1. Status Bar
Information is displayed in the
status bar , at the
bottom of the Image window :
Distance between the original point and the mouse pointer, in
pixels.
Angle, in every quadrant, from 0° to 90°.
Pointer coordinates relative to the original point.
6. 5. 2. Activating the Tool
You can get to the Measure Tool from the image-menu through:
Tools → Measure ,
or by clicking the tool icon :
in Toolbox .
6.5.3. Key modifiers (Defaults) Shift
Holding down the Shift allows to start a new
measure from the pointed point without deleting the previous
measure. Angle is measured from the previous line and not from
the default horizontal. The mouse pointer goes with a
“ + ” sign. So, you can
measure any angle on the image.
Ctrl
Holding down the Ctrl key puts the tool
into constrained straight line mode. The orientation of the
line is constrained to the nearest multiple of 15 degrees.
Ctrl key pressed and click on an end point
creates a horizontal guide. The mouse pointer goes with the
icon.
Alt Alt key and click on an end point creates a
vertical guide. The mouse pointer goes with the
icon.
Ctrl + Alt
This key combination and click on a measure line allows to move
the measure.
Ctrl + Alt
key combination and click on an end point creates a vertical and a
horizontal guides.
6.5.4. Options Figure 14.186. “ Measure ” tool options Use Info Window
This option will display an Info Window dialog that details the
measure tool results. The results are more complete on the status
bar.
6.5.5. Measuring surfaces
You can't measure surfaces directly, but you can use the
Histogram that gives you
the number of pixels in a selection.
6.4. Zoom 6.6. Text
 Report an error in Bugzilla  4. 3. Move 4.3. Move 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 3. Move Figure 14.113. The Move tool in Toolbox
The Move Tool is used to move layers, selections, paths or guides. It
works also on texts.
 4. 3. 1. Activating the Tool
You can access the Move Tool in different ways:
From the image menu bar
Tools → Transform Tools → Move ,
By clicking the tool icon :
.
By using the keyboard shortcut M .  The Move tool is automatically activated when you create a
guide.
Note
Holding down the space bar changes the active
tool to Move temporarily. The Move tool remains active as long as
the space bar is held down. The original tool is reactivated
after releasing the space bar. This behaviour exists only if the
Switch to Move tool option is
enabled in
Edit → Preferences → Image Windows → Space Bar .
4.3. 2. Options Figure  14. 114. Move Tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Move Note
These options are described in
Transform tools common options .
Keep in mind that your Move choice persists after quitting the
tool.
Tool toggle (Shift) If Move is on “ Layer ” Pick a layer or guide
On an image with several layers , the mouse pointer turns to
a crosshair when it goes over an element belonging to the
current layer. Then you can click-and-drag it . If the mouse
pointer has a small hand shape (showing that you do
not pick an element of the active
layer), you will move a non-active layer instead (it becomes
the active layer while moving).
If a guide exists on your image, it will turn to red when
the mouse pointer goes over . Then it is activated and you
can move it .
Move the active layer
Only the current layer will be moved. This may be useful if
you want to move a layer with transparent areas, where you
can easily pick the wrong layer.
If Move is on “ Selection ”
The selection's outline will be moved ( see
Section 2.1, “Moving a Selection” ).
If Move is on “ Path ” Pick a path
That's the default option. The mouse pointer turns to a
small hand when it goes over a
visible path .
Then you can move this path by click-and-dragging it (it
will be the active path while moving).
Move the active path
Only the current path will be moved. You can change the
current path in the
Path Dialog .
4.3.3. Summary of Move tool actions Moving a selection
The Move tool allows to move the selection outline only. If the
Move Mode is “ Layer ” , you must hold down
Ctrl + Alt keys .
If the Move Mode is Selection, you can click-and-drag any point in
canvas to move the selection outline . You can also use the arrow
keys to move selections precisely. Then, holding down the
Shift key moves then by increments of 25 pixels.
When you move a selection with the Move tool, the center of the
selection is marked with a small cross. This cross and selection
boundaries snap to guides or grid if the
View → Snap to Guides (or Grid)
option is checked: this makes aligning selections easier.
See Moving
selections for other possibilities.
Moving a layer
The Move Mode must be “ Layer ” . Then you can choose
between Move the Active Layer and, if you
have one or more layers, Point to Layer (or
Guide) .
Moving Grouped Layers
If layers are grouped (with the little chain symbol) they will all
move, regardless of which layer is currently active.
Moving a guide
When you pull a guide from a ruler, the Move tool is automatically
activated . That's not the case after using another tool, and you
have to activate it by yourself. When the mouse pointer goes over a
guide, this guide turns to red and you can click-and-drag to move
it.
Moving a path
The Path Tool dialog has its own moving function: see
Section 6.2, “Paths” . But you can also use the Move
Tool. The Move Mode must be set to “ Path ” . Note that
the path becomes invisible; make it visible in the Path Dialog.
You can choose the path to be moved or move the active path.
Moving a text
Every text has its own layer and can be moved as layers. See
Section 6.6, “Text” .
4.2. Align 4.4. Crop
 Report an error in Bugzilla  3. 7. Paintbrush 3.7. Paintbrush 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 7. Paintbrush Figure 14.71. Paintbrush
The paintbrush tool paints fuzzy brush strokes. All strokes are rendered
using the current brush.
 3. 7. 1. Activating the Tool
You can call the Paintbrush Tool in the following
order, from the image-menu:
Tools → Paint Tools → Paintbrush .
The Tool can also be called by clicking the tool icon :
or by using the P keyboard shortcut. 
3. 7. 2. Key modifiers (Defaults) Ctrl
This key changes the paintbrush to a
Color Picker .
Shift
This key places the paintbrush into straight
line mode. Holding Shift while clicking
Button 1 will generate a straight
line. Consecutive clicks will continue drawing straight lines
that originate from the end of the last line.
3. 7. 3. Options Figure  14. 72. Paintbrush tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity ; Brush; Dynamics; Dynamics Options;
Apply Jitter; Smoot Stroke; Incremental:
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
3. 6. Pencil 3.8. Eraser
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6. 2. Paths 6.2. Paths 6. Other  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 2. Paths Figure 14.178. Paths tool
The Paths tool allows to create complex selections called Bézier Curves, a
bit like Lasso but with all the adaptability of vectorial curves. You can
edit your curve, you can paint with your curve, or even save, import, and
export the curve. You can also use paths to create geometrical figures.
Paths have their own dialog box:
Dialog .
6. 2. 1. Activating the Tool You can get this tool in several ways :
In the image menu through
Tools → Paths ,
By clicking the tool icon :
in Toolbox ,
or by using the B keyboard shortcut.
6. 2.2. Key modifiers (Defaults) Note
Help messages pop up at the bottom of the image window to help you
about all these keys.
Shift
This key has several functions depending on context. See Options
for more details.
Ctrl ; Alt
Three modes are available to work with the Paths tool:
Design , Edit
and Move . Ctrl key
toggles between Design and Edit. Alt (or
Ctrl + Alt )
key toggles between Design and Move.
6.2. 3. Options Figure  14. 179. “ Path ” tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Design Mode
By default, this tool is in Design mode.
You draw the path by clicking successively. You can move
control points by clicking on them and dragging them. Between
control points are segments.
Numbers are steps to draw a two segments straight path.
Curved segments are easily built by dragging a segment or a
new node. Blue arrows indicate curve. Two little handles
appear that you can drag to bend the curve.
Tip
To quickly close the curve, press Ctrl
key and click on the initial control point. In previous
versions, clicking inside a closed path converted it into
Selection. Now, you can use the Create
selection from path button or
the Path to Selection button
in the Path Dialog.
Tip
When you have two handles, they work symmetrically by
default. Release the pressure on the mouse button to move
handles individually. The Shift key will
force the handles to be symmetrical again.
Several functions are available with this mode: Add a new node :
If the active node (a small empty circle after clicking on a node)
is at the end of the path, the mouse pointer is a '+' sign and a new
node is created, linked to the previous one by a segment. If the
active node is on the path, the pointer is a square and you can
create a new component to the path. This new component is
independent from the other, but belongs to the path as you can see
on the Path dialog. Pressing Shift
forces the creation of a new component.
Move one or several nodes : On a node,
the mouse pointer becomes a 4-arrows cross. You can click
and drag it .
You can select several nodes by Shift and
click and move them by click and drag.
Pressing Ctrl + Alt
allows to move all the path, as a
selection.
Modify handles : You have to Edit a node
before. A handle appears. Drag it to bend the curve.
Pressing Shift toggles to symmetric handles.
Modify segment : When the mouse pointer
goes over a segment, it turns to a 4-arrows cross. Click-and- drag
it to bend the segment. As soon as you move, handles appear
at both ends of the segment. Pressing Shift
key toggles to symmetric handles.
Edit Mode Edit performs functions which are not
available in Design mode. With this
mode, you can work only on the existing path. Outside, the
pointer is a small crossed circle ( on the whole image if
there is no path!) and you can do nothing.
Add a segment between two nodes : Click
on a node at one end of the path to activate it. The pointer is
like a union symbol. Click on an other node to link both
nodes. This is useful when you have to link unclosed
components.
Remove a segment from a path : While pressing
Shift + Ctrl
key combination, point to a segment. Pointer turns to -.
Click to delete the segment.
Add a node to a path : point to a
segment. Pointer turns to +. Click where you want to place
the new control point.
Remove a node : While pressing
Shift + Ctrl
key combination, point to a node. Pointer turns
to -. Click to delete the node.
Add a handle to a node : Point to a
node. Pointer turns to small hand. Drag the node: handle
appears.
Pressing Shift toggles to symmetric
handles.
Remove a handle from a node : While pressing
Shift + Ctrl
key combination, point to a handle. The pointer
doesn't turn to the expected - and remains a hand. Click
to delete the handle.
Caution
No warning before removing a node, a segment or a handle.
Move Mode Move mode allows to move one or all
components of a path. Simply click on the path and drag it.
If you have several components, only the selected one is moved. If
you click and drag outside the path, all components are moved.
Pressing Shift
key toggles to move all components also.
Polygonal
With this option, segments are linear only. Handles are not
available and segments are not bent when moving them.
Create selection from path
This button allows creation of a selection that is based on
the path in its present state. This selection is marked with
the usual "marching ants". Note that the path is still present:
current tool is still path tool and you can modify this path without
modifying the selection that has become independent. If you
change tool, the path becomes invisible, but it persists in
Path Dialog and you can re-activate it.
If the path is not closed, GIMP will close it with a straight line.
As the help pop-up tells, pressing Shift
when clicking on the button will add the new selection to an
eventually pre-existent. Pressing the Ctrl will
subtract the selection from the pre-existent and the
Shift + Ctrl
key combination will intersect the two selections.
Stroke path
In previous versions, you could access to this command
only by the Edit sub-menu in the Image Menu. Now you can
access to it also via this button. See
Section 3.18, “Stroke Path” and
Section 5, “
Paths
” .
See the “ Path ” concept.
6. Other 6.3. Color Picker
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3. 6. Pencil 3.6. Pencil 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 6. Pencil Figure 14.69. Pencil tool
The Pencil tool is used to draw free hand lines with a hard edge. The
pencil and paintbrush are similar tools. The main difference between the
two tools is that although both use the same type of brush, the pencil
tool will not produce fuzzy edges, even with a very fuzzy brush. It does
not even do anti-aliasing.
Why would you want to work with such a crude tool? Perhaps the most
important usage is when working with very small images, such as icons,
where you operate at a high zoom level and need to get every pixel exactly
right. With the pencil tool, you can be confident that every pixel within
the brush outline will be changed in exactly the way you expect.
Tip
If you want to draw straight lines with the Pencil (or any of several
other paint tools), click at the starting point, then hold down
Shift and click at the ending point.
 3. 6.1. Activating the Tool
The Pencil Tool can be called from the image-menu:
Tools → Paint Tools → Pencil
The Tool can also be called by clicking the tool icon :
or by clicking on the N keyboard shortcut. 
3. 6. 2. Key modifiers (Defaults) Ctrl
This key changes the pencil to a
Color Picker .
Shift
This key places the pencil tool into straight
line mode. Holding Shift while clicking
Button 1 will generate a straight
line. Consecutive clicks will continue drawing straight lines
that originate from the end of the last line.
3. 6. 3. Options Figure  14. 70. “ Pencil ” Tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Mode; Opacity ; Brush; Dynamics; Dynamics Options;
Apply Jitter; Smooth Stroke; Incremental
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
3. 5. Blend 3.7. Paintbrush
 Report an error in Bugzilla  3. 13. Perspective Clone 3. 13. Perspective Clone 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 13. Perspective Clone Figure 14.90. The “ Perspective Clone ” tool in the Toolbox
This tool allows you to clone according to the perspective you want.
First, set the wanted vanishing lines in the same way as with the Perspective tool. Then
copy the source area in the same way as with the Clone tool.
 3. 13. 1. Activating the Tool
There are different possibilities to activate the tool:
From the image-menu :
Tools → Paint tools → Perspective Clone .
The Tool can also be called by clicking the tool icon :
in the Toolbox.  3. 13. 2. Key modifiers (Defaults) Ctrl Ctrl -click allows you to select a new clone source.
Shift
When the source is set and you press this key, you will see a thin
line connecting the previously clicked point with the current
pointer location. If you click again, while continuing to hold
down the Shift key, the tool will clone along
this line. Particularly useful when cloning from a pattern.
3.13. 3. Options Figure  14. 91. Perspective Clone tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Operating mode
When using this tool you first have to choose
Modify Perspective . This works like the tool
perspective .
Then you choose Perspective Clone and use
this in the same way as the
Clone tool.
Mode; Opacity; Brush; Dynamics; Dynamics Options; Fade Options;
Apply Jitter; Smooth Stroke; Hard Edge
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
Source , Alignment
This are the same as in the tool
Clone .
3.13.4. Example Figure 14.92. “ Perspective Clone ” example
The “ Modify Perspective Plane ” is checked. Vanishing
lines have been placed.
The “ Perspective Clone ” option is checked. The
white rectangle has been cloned. You see it goes smaller going
away.
3.12. Heal 3.14. Blur/Sharpen
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4.8. Perspective 4.8. Perspective 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 8. Perspective Figure 14.130. Perspective tool
The Perspective Tool is used to change the “ perspective ” of
the active layer content, of a selection content or of a path. When you
click on the image , according to the Preview type you have selected, a
rectangular frame or a grid pops up around the selection (or around the
whole layer if there is no selection ), with a handle on each of the four
corners. By moving these handles by click-and-drag, you can modify the
perspective. At the same time, a “ Transformation
information ” pops up, which lets you valid the transformation. At
the center of the element, a circle lets you move the element by
click-and-drag.
Note
This tool is not actually a perspective tool, as it doesn't impose
perspective rules. It is better described as a distort tool.
 4. 8. 1. Activating the Tool
You can access the Perspective tool in different ways:
From the image menu bar
Tools /
Transform Tools
Perspective ,
By clicking the tool icon :
in Toolbox ,
By using the
Shift + P key
combination. 
4. 8. 2. Options Figure  14. 131. “ Perspective ” tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Transform ; Interpolation; Direction; Clipping; Preview; Guides
Note
These options are described in
Transform tools common options .
4. 8.3.
The information window for perspective transformation
Figure 14.132.
The information window of the “ Perspective ” tool
Matrix
The information window shows a mathematical representation
of the perspective transformation. You can find more
information about transformation matrices on
Wikipedia .
4.7. Shear 4.9. Flip
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5. 9. Posterize 5.9. Posterize 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 9. Posterize
This tool is designed to intelligently weigh the pixel colors of the
selection or active layer and reduce the number of colors while
maintaining a semblance of the original image characteristics.
 5. 9. 1. Activating the Tool You can get to this tool in several ways:
In the image menu through
Tools → Color Tools → Posterize or
Colors → Posterize .
By clicking on the tool icon
in Toolbox , if this tool has been installed there.  For this, please
refer to Section 1.7, “Toolbox” .
5. 9.2. Options Figure 14.173. Posterize tool options Posterize Levels
This slider and the input boxes with arrow-heads allow you
to set the number of levels (2-256) in each RGB channel that
the tool will use to describe the active layer. The total number
of colors is the combination of these levels. A level to 3
will give 2 3 = 8 colors.
Preview
The Preview check-box makes all changes dynamically so that
they can be viewed straight away.
5. 9.3. Example Figure 14. 174. Example for the “ Posterize ” tool
Image posterized in 4 levels. The histogram shows the 4 levels
and 10 colors, counting black and white also.
5.8. Curves 5.10. Desaturate
 Report an error in Bugzilla  2. 2. Rectangle Selection 2. 2. Rectangle Selection 2. Selection Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Rectangle Selection Figure 14.10. Rectangle Select icon in the Toolbox
The Rectangle Selection tool is designed to select rectangular regions of
the active layer: it is the most basic of the selection tools, but very
commonly used. For information on selections and how they are used in GIMP
see Selections ;
for information on features common to all selection tools see
Selection Tools .
This tool is also used for rendering a rectangle on an image. To render a
filled rectangle, create a rectangular selection, and then fill it using
the Bucket Fill tool .
To create a rectangular outline, the simplest and most flexible approach
is to create a rectangular selection and then
stroke it.  2. 2. 1. Activating the tool
You can access the Selection Tool in different ways:
from the image menu bar
Tools → Selection Tools → Rectangle Select ,
by clicking on the tool icon
in the ToolBox,
by using the keyboard shortcut R . 
2. 2. 2. Key modifiers Note
See Selection Tools for
help with modifier keys that affect all these tools in the same
way. Only effects options that are specific to this tool are explained
here.
Ctrl
Pressing the Ctrl key after starting
your selection, and holding it down until you are finished,
causes your starting point to be used as the center of the
selected rectangle, instead of a corner. Note that if you
press the Ctrl key before
starting to make the selection, the resulting selection will be
subtracted from the existing selection. The cursor becomes
Shift
If you press the Shift key
before starting the selection, the
resulting selection will be added to the existing one. The cursor
becomes
Pressing the Shift key after
starting your selection, toggles the Fixed
option, and holding it down until you are finished,
will constrain the selection to a square, if it is your first
selection. Later, with the default Aspect Ratio
, your selection will respect the aspect ratio of the
previous selection.
Ctrl + Shift
Pressing both keys after starting your selection
combines the two effects, giving you a square selection centered
on your starting point. Note that pressing these keys before
starting your selection intersects the resulting selection with
the existing one and the pointer change shape accordingly :
2.2.3. Tool manipulation Figure 14.11. Example of Rectangle Selection.
When this tool is selected the mouse pointer is displayed like this:
as soon as it is over the image. A drag and drop allows to get a
rectangular (or square) shape. When the mouse button is relaxed, a
dotted line ( “ marching ants ” ) outlines the selection. It's
not necessary to adjust the selection with care; you can resize it
easily later.
When the pointer is moving on the canvas, the pointer and selection
aspects change :
- outside the selection it looks like previously; this allows to design
a new selection but will erase the existing one if this isn't combined
with an action on the relevant key to add or subtract another selection
as described in the previous paragraph.
- within selection peripheral parts, the mouse pointer changes into
various shapes when overflying rectangular sensitive and clearly marked
areas. These handles allow you to resize the
selection. In selection corners the pointer changes into a shape
according to the context; for instance in the low right corner it
becomes:
.
So, by click-and-dragging these areas, you can magnify or shrink the
selection size. Over median selection parts, lateral, low or up,
pointer is changed into appropriate shapes according to the context.
For instance , when the mouse pointer is over the median right side, the
pointer looks like:
.
So you can click-and-drag to magnify or to shrink the selection size by
moving the chosen boundary.
- inside selection central area the mouse pointer looks like usual for
object manipulation, i.e.:
.
So you can move the whole selection by a click-and-drag.
Moreover, if you have not unchecked the Highlight
option, your work will be easier because what is out the selection will be
darkest than what is in the selection, and then the selection seems
highlighted.
Tip
If you use moving keys you can move the selection or modify its size
by one pixel step. If you use it in combination with
Shift you can move it by a 25 pixel step.
Figure 14.12. Sensitive selection areas
Display of all possible pointers in function of their localization
with respect to the selection area.
After creating and modifying the selection, you will have to exit this
editing mode (and commit any changes). You can do this with a single
click inside the selection or by pressing the Enter
key. Or you can just use a non-selection tool and, for example, fill or
paint the selection.
2.2. 4. Tool Options Figure  14. 13. Tool Options for the Rectangle Select tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Note
See Selection Tools
for help with options that are common to all these tools. Only
options that are specific to this tool are explained here.
Mode; Antialiasing; Feather edges
Common select options. Rounded corners
If you enable this option, a slider appears. You can use this to
adjust the radius that is used to round the corners of the
selection.
Expand from center
If you enable this option, the point the selection is started by
pressing the mouse button is used as center of the selected area.
Fixed
This menu allows you the option of constraining the shape of
the rectangle in different ways.
Aspect ratio
This option allows you to design and resize the selection
while keeping the aspect ratio fixed and written within the
relevant box. By default the ratio is 1:1 (so we have a
square) but it can be changed. With the two little landscape
and picture icons, you can invert this ratio.
Width
With this choice you can fix the width of the selection .
Height
With this choice you can fix the height of the selection .
Size
With this choice you can fix the width and height of the
selection.
Position
These two text fields contain the current horizontal and vertical
coordinates of the upper left corner of the selection. You can use
these fields to adjust the selection position precisely.
Size
These two text fields contain the current width and height of the the selection. You can use these fields to adjust the selection
size precisely.
Highlight
If you enable this option, the selected area is emphasized by a
surrounding mask to make visual selection much easier.
Guides
With this menu you can select the type of guides that is shown
within the selection to make the creation of a selection easier,
respecting Photo composition rules .
Six options are available:
No Guides Center lines Rule of thirds Rule of fifths Golden sections Diagonal lines
Auto Shrink Selection
The Auto Shrink Selection check-box will
make your next selection automatically shrink to the nearest
rectangular shape available on the image layer. The
algorithm for finding the best rectangle to shrink to is
“ intelligent ” , which in this case means that it
sometimes does surprisingly sophisticated things, and sometimes
does surprisingly strange things. In any case, if the region
that you want to select has a solid-colored surround,
auto-shrinking will always pick it out correctly. Note that
the resulting selection does not need to have the
same shape as the one you sweep out.
Shrink merged
If Sample Merged
is also enabled, then Auto Shrink will use the pixel information
from the visible display of the image, rather than just from the
active layer. For further information regarding Sample Merge , see
the glossary entry
Sample Merge .
2. Selection Tools 2.3. Ellipse Selection
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4. 5. Rotate 4.5. Rotate 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 5. Rotate Figure 14.119. The Rotate tool in Toolbox 4.5.1. Overview
This tool is used to rotate the active layer, a selection or a path .
When you click on the image or the selection with this tool a
Rotation Information dialog is opened.
There, you can set the rotation axis, marked with a point, and the
rotation angle. You can do the same by dragging the mouse pointer on
the image or the rotation point.
 4. 5. 2. Activating the Tool
You can access the Selection Tool in different ways:
from the image menu bar
Tools → Transform Tools → Rotate ,
by clicking the tool icon :
in the Toolbox,
by using the
Shift + R
key combination. 
4. 5. 3. Key modifiers (Defaults) Ctrl
Holding Ctrl will constrain the rotation
angle to 15 degrees increments.
4. 5.4. Options Figure  14. 120. Rotation tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Transform ; Direction, Interpolation; Clipping; Preview; Guides
Note
These options are described in
Transform tools common options .
Transform Direction
The Transform Direction sets which way or direction a layer is
rotated. The Normal mode will rotate the layer as one might
expect. If a layer is rotated 10 degrees to the right, then the
layer will be rendered as such. This behaviour is contrary to
Corrective rotation.
Corrective Rotation is primarily used to repair digital images
that are not straight. If the image is 13 degrees askew then you
need not try to rotate by that angle. By using Corrective Rotation
you can rotate visually and line up the layer with the image.
Because the transformation is reversed, or performed backwards,
the image will be rotated with sufficient angle to correct the
error.
Constraints 15 Degrees ( Ctrl) will constrain the rotation
to angles divisible by 15 degrees.
4.5.5. The Rotation Information window Figure 14.121. The Rotation Information dialog window Angle
Here you can set the rotation angle, from -180° to +180°, i.e.
360°.
Center X/Y
This option allows you to set the position of the rotation center,
represented by a cross surrounded by a circle in the image. A
click-and-drag on this point also allows you to move this center
even outside the image. Default unit of measurement is pixel , but
you can change it by using the drop-down list.
Figure 14.122. The rotating center
The layer rotated around the rotating center outside the
image
Note
You can also rotate layers with
Layer → Transform → Arbitrary Rotation ...
4.4. Crop 4.6. Scale
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4. 6. Scale 4.6. Scale 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 6. Scale Figure 14.123. The Scale tool in Toolbox 4.6.1. Overview
The Scale Tool is used to scale layers, selections or paths (the
Object).
When you click on image with the tool the Scaling Information dialog box
is opened, allowing to change separately Width
and Height .
At the same time a Preview (possibly with a grid or an outline) is
superimposed on the object and handles appear on corners and borders
that you can click and drag to change dimensions. A small circle
appears at center of the Preview allowing to move this preview.
 4. 6. 2. Activating the Tool
You can access the Scale Tool in different ways:
from the image menu bar
Tools → Transform Tools → Scale ,
by clicking the tool icon :
in the Toolbox,
by using the
Shift + T
key combination. 
4. 6. 3. Key modifiers (Defaults) Ctrl
Holding the Ctrl key down
will toggle the Keep Aspect option.
4.6. 4. Tool Options Figure  14. 124. Tool options for the Scale tool
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Transform; Interpolation; Direction; Clipping; Preview; Guides
Note
These options are described in
Transform tools common options .
Note
The Transform mode works on the active layer only . To work on
all layers of the image, use
Scale Image .
Keep Aspect (Ctrl)
When you move a corner of the selection frame, this option will
constrain the scale such as the Height/Width ratio of the layer
will remain constant. Note that this doesn't work with border
handles. Note also that it toggles the linking chain in the
dialog.
4.6.5. The Scaling Information dialog window Figure 14.125. The Scaling Information dialog window Width/Height
Here, you can set Width and Height you want to give to the object.
The default unit of measurement is pixel . You can change it by
using the drop-down list. These values are also automatically
changed when you drag handles in the image. If the associated
linking chain is broken, you can change Width and Height
separately.
4.5. Rotate 4.7. Shear
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4. 7. Shear 4.7. Shear 4. Transform Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 7. Shear Figure 14.126. The Shear tool in Toolbox
Shear tool is used to shift one part of an image , a layer, a selection or
a path to a direction and the other part to the opposite direction. For
instance, a horizontal shearing will shift the upper part to the right and
the lower part to the left. A rectangle becomes a diamond. This is not a
rotation: the image is distorted. To use this tool after selecting, click
on the image or the selection : a grid is possibly surperimposed and the
Shearing Information dialog is opened. By dragging the mouse pointer on
the image you distort the image, horizontally or vertically according to
the direction given to the pointer. When you are satisfied, click on
the Shear button in the info dialog to validate.
Figure 14.127. Shear example Note
You can't shear both ways at the same time, you have to use the
shear tool twice on end.
 4. 7. 1. Activating the Tool
You can access the Shear Tool in different ways:
from the image menu bar
Tools → Transform Tools → Shear ,
by clicking on the tool icon :
in Toolbox ,
by using the
Shift + S key
combination. 
4. 7. 2. Options Figure  14. 128. Shear tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Transform Direction; Interpolation; Clippping; Preview; Guides
Note
These options are described in
Transform tools common options .
4. 7.3. Shearing Information Figure 14.129. Shearing Information window Shear magnitude X
Here, you can set the horizontal shearing amplitude. A positive
value produces a clock-wise tilt. A negative value gives a
counter-clock-wise tilt. The unit used by shearing are
half-pixels.
Shear magnitude Y As above, in the vertical direction. 4.6. Scale 4. 8. Perspective
 Report an error in Bugzilla  3. 15. Smudge 3.15. Smudge 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 15. Smudge Figure 14.95. Smudge tool
The Smudge tool uses the current brush to smudge colors on the active
layer or a selection. It takes color in passing and uses it to mix it to
the next colors it meets, on a distance you can set .
3.15. 1. Activating the Tool
You can find the Smudge tool in various ways :
through
Tools → Paint Tools → Smudge.
in the image menu,
by clicking on the tool icon :
in Toolbox ,
or by pressing the S key on keyboard.
3.15. 2. Key modifiers (Defaults) Shift
The Shift key places the smudge tool into
straight line mode. Holding Shift while clicking
Button1 will smudge in a straight
line. Consecutive clicks will continue smudging in straight
lines that originate from the end of the last line.
Ctrl
Using Ctrl with Shift , you can
constrain the angle between two successive lines to vary by steps
of 15°.
3.15. 3. Options Figure  14. 96. The Smudge tool in Toolbox
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Opacity; Brush; Dynamics; Dynamics Options; Fade Options;
Apply Jitter; Hard Edge ; Rate
See the Common Paint Tool
Options for a description of tool options that apply to many or all
paint tools.
3. 14. Blur/Sharpen 3.16. Dodge/Burn
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6. 6. Text 6.6. Text 6. Other  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 6. Text Figure 14.187. The Text tool in Toolbox
The Text tool places text into an image. With GIMP-2.8 ,
you can write your text directly on the canvas. No Text Editor is needed
anymore (although you can still use it if you want by checking the
Use editor option in the Tool Options dialog. A text
toolbar has been added which allows you to edit text in different ways but
you can still go on using the Text Option dialog , to
change the font, color and size of your text, and justify it,
interactively. Right clicking on the frame opens a context menu that allows
you to copy, cut, paste, load a text...
As soon as you type your text, it appears on the canvas in a rectangular
frame. If you draw the rectangular frame first, the text is automatically
adapted to the frame size. You can enlarge this frame as you do with
rectangular selections.
To move the text on canvas, you have to select the Move tool and click
on a character to drag the frame and its text.
 6. 6. 1. Activating the Tool
You can access this tool in several ways:
In the image menu through
Tools → Text ,
by clicking the tool icon
in Toolbox ,
or by using the T keyboard shortcut.  6.6. 2. Options Figure  14. 188. Text tool options
Normally, tool options are displayed in a window attached under the
Toolbox as soon as you activate a tool. If they are not, you can access
them from the image menu bar through
Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.  Font
Click on the fonts button Aα to open
the font selector of this tool, which offers you a list of
installed X fonts.
At the bottom of the font selector you find some icons which
act as buttons for:
resizing the font previews,
selecting list view or grid
view ,
opening the font
dialog .
Choose a font from the installed fonts. When you select a font it
is interactively applied to your text.
Tip
You can use the scroll wheel of your pointing device (usually
your mouse) on the fonts button in order to quickly change the
font of your text (move the pointer on the fonts button, and
don't click, just use the wheel button).
Size
This control sets the size of the font in any of several
selectable units.
Use editor
Use an external editor window for text editing instead of
direct-on-canvas editing.
Antialiasing
Antialiasing will render the text with much smoother edges and
curves. This is achieved by slight blurring and merging of the
edges. This option can radically improve the visual appearance of
the rendered typeface. Caution should be exercised when using
antialiasing on images that are not in RGB color space.
Hinting
Uses the index of adjustment of the font to modify characters in
order to produce clear letters in small font sizes.
Color
Color of the text that will be drawn next. Defaults to black.
Selectable from the color picker dialog box that opens when the
current color sample is clicked.
Tip
You can also click-and-drag the color from the Toolbox color
area onto the text.
Justify
Causes the text to be justified according to any of four rules
selectable from the associated icons.
Indent
Controls the indent spacing from the left margin, for the first
line.
Line Spacing
Controls the spacing between successive lines of text. This
setting is interactive: it appears at the same time in image text.
The number is not the space between lines itself, but how many
pixels must be added to or subtracted from this space (the value
can be negative).
Letter Spacing
Controls the spacing between letters. Also in this case the number
is not the space itself between letters, but how many pixels must
be added to or subtracted from this space (the value can be
negative).
Box
Concerns the text box. The associated drop down list offers two
options:
Dynamic : default option. The size
of the text box increases as you type. Text may go out of the
image. You have to press the Enter key to add a
new line. The indent option indents all lines. If you increase the
box size, the option turns to "Fixed".
Fixed : you must enlarge the text
box first. Else, usual shortcuts are active! The text is limited
by the right side of the box and continues on next line. This is
not true new line: you must press the Enter key
to add a real new line. The text may go out the lower border of the
image. The indent option works on the first line only.
6.6.3. The Text tool context menu
You get this menu by right clicking in a text frame with handles.
Cut, Copy, Paste, Delete : these options concern
a selected text. They remain grayed out as long as no text is
selected. “ Paste ” is activated if the clipboard
is full of text.
Open text file : this command opens a file browser
where you can find the wanted text file.
Clear : this command deletes all the text,
selected or not.
Path from text : this command creates a
path from the outlines of the current text. The result is not
evident. You have to open the Path dialog and make path visible.
Then select the Path tool and click on the text. Every letter
is now surrounded with a path component. So you can modify
the shape of letters by moving path control points.
This command is similar to
Layer → Text to Path .
Text along path :
This option is enabled only if a
path exists. When your
text is created, then create or import a path and make it active.
If you create your path before the text, the path becomes
invisible and you have to make it visible in the Path Dialog.
This command is also available from the “ Layer ” menu:
Figure 14.189.
The Text along Path command among text commands in the Layer menu
This group of options appears only if a layer text exists.
If you want to use a text that already exists, make it active
in the Layer dialog ,
select the Text tool and click on the text in the image window.
Click on the Text along Path button. The
text is bent along the path. Letters are represented with their
outline. Each of them is a component of the new path that
appears in the Path
dialog . All path options should apply to this new path.
Figure 14.190. “ Text along Path ” example From Left to Right / From Right to Left : fix
the writing direction of your language.
6.6.4. Text Editor Figure 14.191. The Text Editor
With GIMP-2.8 , this text editor is available only if
the Use editor option is checked. It persists
probably because all its functions are not transferred to the
direct-on-canvas mode, for instance the Unicode characters.
You can correct the text you are writing and you can change the text
font with the Font Editor.
As soon as you start writing, a Text layer is created in the Layer
Dialog. On an image with such a layer (the image you are working on, or
a .xcf image), you can resume
text editing by activating this text layer then clicking on it (double
click). Of course, you can apply to this text layer the same functions
you use with other layers.
To add another text to your image click on a non-text layer: a new Text
Editor will appear and a new text layer will be created. To pass from a
text to another one activate the corresponding text layer and click on
it to activate the editor.
You can get Unicode characters with
Ctrl + Shift + U
plus hexadecimal Unicode code of the desired char , for example:
Figure 14.192. Entering Unicode characters Ctrl + Shift + U 4 7 Enter
Of course this feature is more useful for entering special (even exotic)
characters, provided that the required glyphs for these characters are
supplied by the selected font — only few fonts support Klingon.
;-)
Unicode 0x47 ( “ G ” ), 0x2665, 0x0271, 0x03C0
The Text Editor options Load Text from file
Text can be loaded from a text file by clicking the folder icon in
the text editor. All the text in the file is loaded.
Clear all text
Clicking this icon clears the editor and the associated text on
the image.
From left to right
This option causes text to be entered from left to right, as
is the case with most Western languages and may Eastern
languages.
From right to left
This option allows text to be entered from right to left, as is
the case with some Eastern languages, such as Arabic (illustrated
in the icon).
Use selected font
Default doesn't use the font you have selected in the Options
dialog. If you want to use it, check this option.
Note See also Section 3, “Text” . 6.5. Measure 6.7. GEGL Operation
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5. 6. Threshold 5.6. Threshold 5. Color Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 6. Threshold
The Threshold tool transforms the current layer or the selection into a
black and white image , where white pixels represent the pixels of the
image whose Value is in the threshold range, and black pixels represent
pixels with Value out of the threshold range.
You can use it to enhance a black and white image (a scanned text for
example) or to create selection masks.
Note
As this tool creates a black and white image , the anti-aliasing of the
original image disappears. If this poses a problem, rather use the
Levels tool.
 5. 6. 1. Activating the Tool
There are different possibilities to activate the tool:
You can access this tool from the image menu through
Tools → Color Tools → Threshold, ,
or through
Colors → Threshold ,
or by clicking on the icon in Toolbox if this tool has been installed in it.  For this,
please refer to Section 1.7, “Toolbox” .
5. 6.2. Options Figure 14.153. Threshold tool options Presets
You can save the color settings of your image by clicking the
Add settings to favourites button
The
button opens a menu:
Figure 14. 154. Preset Menu
which lets you Import Settings from File or
Export Settings to File ,
and gives you access to the Manage Save Settings dialog:
Figure 14. 155. Manage saved Settings Dialog Threshold range
The Threshold tool provides a visual graph, a histogram, of the
intensity value of the active layer or selection . You can set the
threshold range either using the input boxes or clicking button 1
and dragging on the graph. It allows you to select a part of the image with some intensity from a background with another
intensity. Pixels inside the range will be white, and the others
will be black. Adjust the range to get the selection you want in
white on black background.
Preview
The Preview toggle allows dynamic updating of the active layer or
selection while changes are made to the intensity level.
5.6.3. Using Threshold and Quick Mask to create a selection mask
That's not always the case, but an element you want to extract from
an image can stand out well against the background. In this case,
you can use the Threshold tool to select this element as a whole.
Grokking the GIMP described a method based on a channel mask, but now,
using the Quick mask
is easier.
First start decomposing you image into its RGB and HSV components by
using the Decompose filter. A
new grey-scaled image is created and the components are displayed as
layers in the Layer Dialog. These layers come with a thumbnail but
it is too small for an easy study. You can, of course, increase the
size of this preview with the dialog menu (the small triangular
button), but playing with the “ eyes ” is more simple to
display the wanted layer in the decompose image. Select the layer
that isolates the element the best.
Figure 14.156.
The original image, the decompose image and its Layer Dialog
Call the Threshold tool from the decompose image. By moving the
black cursor, fit threshold to isolate the best the element you want
to extract . This will probably not be perfect: we will enhance the
result with the selection mask we are going to create.
Warning
Make sure you have selected the right layer when you call the
Threshold tool: when it is opened, you can't change to another
layer.
Figure 14.157. The selected layer after threshold fit
We got the best outline for our flower. There are several red
objects which we must remove.
Make sure the image displaying the selected layer is active and
copy it to the clipboard with
Ctrl + C .
Now, make the original image active. Click on the
Quick Mask button at the bottom- left corner
of the image window: the image gets covered with a red (default)
translucent mask. This red color does not suit well to our image
with much red: go to the Channel Dialog, activate the
“ Quick mask ” channel and change this color with the
Edit Channel Attributes . Come back to the
original image. Press
Ctrl + V to
paste the previously copied layer.
Figure 14.158. The mask
Voilà. Your selection mask is ready: you can improve the selection
as usually. When the selection is ready, disable the Quick mask by
clicking again on its button: you will see the marching ants around
the selection.
Figure 14.159. The result
We used the Zoom to work at a pixel level, the Lasso to remove large
unwanted areas, the pencil (to get hard limits), black paint to
remove selected areas, white paint to add selected areas, especially
for stem.
5.5. Brightness-Contrast 5. 7. Levels
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6. 4. Zoom 6.4. Zoom 6. Other  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 4. Zoom Figure 14.183. The “ Zoom ” tool in Toolbox
The Zoom Tool is used to change the zoom level of your working image.
If you only click on the image, the zoom is applied to the whole image.
But you can also click- and-drag the mouse pointer to create a zoom
rectangle. Then, the action of this rectangle is better understood if the
“ Allow window resizing ”
option is unchecked: you can see that the content of this rectangle will
be enlarged or reduced so that its biggest dimension fit the corresponding
dimension of the image window ( if the biggest dimension of the rectangle
is width, then it will fit the width of the image window).
6. 4. 1. Activating the Tool
You can get to the Zoom Tool from the image-menu through :
Tools → Zoom ,
or by clicking the tool icon :
in Toolbox .
6. 4.2. Key modifiers (Defaults) Ctrl
Holding Ctrl when clicking on a point of your
image will change the zoom direction from zooming in to zooming
out.
Ctrl + Mouse wheel
Spinning the mouse wheel, while pressing Ctrl ,
varies the zoom level.
6.4.3. Options Figure 14.184. Zoom tool options Auto-resize window
This option will allow the canvas to be resized if the zoom level
dictates it.
Tool Toggle
The two available tool toggles are used for changing the zoom
direction between zooming in and zooming out.
6.4.4. Zoom menu
Using the Zoom tool is not the only way to zoom an image.
The Zoom menu provides
access to several functions for changing the image magnification
level. For example, you can easily choose an exact magnification
level from this menu.
6.3. Color Picker 6.5. Measure
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3. 3. Brush Tools (Pencil, Paintbrush, Airbrush) 3.3. Brush Tools (Pencil, Paintbrush, Airbrush) 3. Paint Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 3. Brush Tools (Pencil, Paintbrush, Airbrush) Figure 14.57. Painting example
Three strokes painted with the same round fuzzy brush (outline shown
in upper left), using the Pencil (left), Paintbrush (middle), and
Airbrush (right).
The tools in this group are GIMP 's basic painting
tools , and they have enough features in common to be worth discussing
together in this section. Features common to all paint tools are
described in the
Common Features
section. Features specific to an individual tool are described in the
section devoted to that tool.
The Pencil is the crudest of the tools in this group : it makes hard,
non-anti-aliased brushstrokes. The Paintbrush is intermediate: it is
probably the most commonly used of the group. The Airbrush is the most
flexible and controllable. This flexibility also makes it a bit more
difficult to use than the Paintbrush, however.
All of these tools share the same brushes, and the same options for
choosing colors, either from the basic palette or from a gradient. All are
capable of painting in a wide variety of modes.
3.3. 1. Key modifiers Ctrl
Holding down the Ctrl key changes each of these
tools to a Color
Picker : clicking on any pixel of any layer sets the
foreground color (as displayed in the
Toolbox Color Area )
to the color of the pixel.
Shift
This key places these tools into straight line mode. Holding
Shift while clicking
Button 1 will generate a straight
line. Consecutive clicks will continue drawing straight lines that
originate from the end of the last line.
3. 2. Dynamics 3.4. Bucket Fill
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5. Color Tools 5. Color Tools Chapter 14. Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. Color Tools 5. 1. Overview Figure 14.138. The Color tools in the Tools menu
Access to the Color tools through the “ classical ” Tools
menu.
Figure 14.139. The Color tools in the Colors menu Access through the Colors menu is easier and faster.
With the Color tools you can manipulate image colors in several ways:
Modify the color balance: Section 5.2, “Color Balance” Adjust hue, saturation and lightness levels :
Section 5.3, “Hue-Saturation”
Render into a greyscale image seen through a colored glass :
Section 5.4, “Colorize”
Adjust brightness and contrast levels:
Section 5.5, “Brightness-Contrast”
Transform into a black and white image depending on pixel value:
Section 5.6, “Threshold”
Change the intensity range in a channel:
Section 5.7, “Levels”
Change color, brightness, contrast or transparency in a sophisticated
way: Section 5.8, “Curves”
Reduce the number of colors : Section 5.9, “Posterize”
Convert all colors to corresponding shades of gray :
Section 5.10, “Desaturate”
5.1.1. Color Tool Presets
Except Desaturate and Posterize, color tools have
presets : saved tool settings that you can retrieve
later.
Three elements:
Presets : this drop-down list
shows you the existing presets. Every time you change
tool settings, a new preset is automatically saved, with date and
hour ; you must be aware of that, to preserve your
computer memory.
The cross : clicking on this
cross opens a window where you can save current settings under the
name you want.
The small triangle : clicking on
this triangle opens a small menu:
Three options: Import settings from file Export settings to file Manage settings
4.10. The Cage Tool 5.2. Color Balance
 Report an error in Bugzilla  9. The “Tools” Menu 9. The “ Tools ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  9. The “ Tools ” Menu 9. 1. Introduction to the “ Tools ” Menu Figure 16.200. Contents of the “ Tools ” menu
The menu entries on the Tools menu access the
GIMP tools. All of the tools available in
GIMP are extensively described in the
Tools section.
8.38. Retinex 10. The “ Filters ” Menu
 Report an error in Bugzilla  6. Other 6. Other Chapter 14. Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. Other 6.1. Overview Figure 14.177. Other Tools in the Tools Menu “ Other ” tools are simply those tools which don't belong to
any main group of tools. You will find here, for example, the important
and powerful Path tool as well as
useful helper tools like the
Color Picker :
Section 6.2, “Paths” Section 6.3, “Color Picker” Section 6.4, “Zoom” Section 6.5, “Measure” Section 6.6, “Text” Section 6.7, “GEGL Operation” 5.10. Desaturate 6.2. Paths
 Report an error in Bugzilla  3. Paint Tools 3. Paint Tools Chapter 14. Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Paint Tools Figure 14.37. The Paint Tools (Tools menu) 3.1. Common Features
The GIMP Toolbox includes thirteen “ paint
tools ” , all grouped together at the bottom (in the default
arrangement).
Figure 14.38. The Paint Tools (Tools Box)
The feature they all have in common is that all of them are used by moving
the pointer across the image display, creating brush-strokes. Four of them
the Pencil ,
the Paintbrush ,
the Airbrush and
the Ink tool
behave like the intuitive notion of “ painting ” with a brush.
Pencil, Paintbrush, and Airbrush are called “ basic painting
tools ” or brush tools .
The other tools use a brush to modify an image in some way rather than
paint on it:
the Bucket Fill fills
with color or pattern;
the Gradient fills with
gradients;
the Eraser erases;
the Clone tool copies from a
pattern, or image;
the Perspective
Clone tool copies into a changed perspective;
the Heal tool corrects small
defects;
the Convolve tool
blurs or sharpens;
the Smudge tool smears;
and the Dodge/Burn tool
lightens or darkens.
The advantages of using GIMP with a tablet instead of a
mouse probably show up more clearly for brush tools than anywhere else:
the gain in fine control is invaluable. These tools also have special
“ Pressure sensitivity ” options that are only usable with a
tablet.
In addition to the more common “ hands-on ” method, it is
possible to apply paint tools in an automated way, by creating a selection
or path and then “ stroking ” it. You can choose to stroke
with any of the paint tools, including nonstandard ones such as the
Eraser, Smudge tool, etc., and any options you set for the tool will be
applied. See the section on
Stroking for more
information.
3.1. 1. Key modifiers Ctrl
Holding down the Ctrl key has a special effect on
every paint tool. For the Pencil, Paintbrush, Airbrush, Ink, and
Eraser, it switches them into “ color picker ” mode, so
that clicking on an image pixel causes GIMP 's
foreground to be set to the active layer's color at that point
(or, for the Eraser, GIMP 's background color).
For the Clone tool, the Ctrl key switches it into
a mode where clicking sets the reference point for copying. For
the Convolve tool, the Ctrl key switches between
blur and sharpen modes; for the Dodge/Burn tool, it switches
between dodging and burning.
Shift
Holding down the Shift key has the same effect on
most paint tools: it places the tool into straight
line mode. To create a straight line with any of the
paint tools, first click on the starting point ,
then press the Shift key.
As long as you hold it down, you will see a thin line connecting
the previously clicked point with the current pointer location.
If you click again, while continuing to hold down the
Shift key, a straight line will be rendered. You
can continue this process to create a series of connected line
segments.
Ctrl + Shift
Holding down both keys puts the tool into
constrained straight line mode. This is
similar to the effect of the Shift key alone,
except that the orientation of the line is constrained to the
nearest multiple of 15 degrees. Use this if you want to
create perfect horizontal, vertical, or diagonal lines.
3.1.2. Tool Options Figure 14.39. Tool options shared by paint tools
Many tool options are shared by several paint tools: these are described
here. Options that apply only to one specific tool, or to a small number
of tools, are described in the sections devoted to those tools.
Mode
The Mode drop-down list provides a selection of paint
application modes. As with the opacity, the easiest way to
understand what the Mode setting does is to imagine that the
paint is actually applied to a layer above the layer you are
working on , with the layer combination mode in the Layers
dialog set to the selected mode. You can obtain a great variety
of special effects in this way. The Mode option is only usable
for tools that can be thought of as adding color to the image:
the Pencil, Paintbrush, Airbrush, Ink, and Clone tools. For the
other paint tools, the option appears for the sake of
consistency but is always grayed out. A list of modes can be
found in Section 2 , “Layer Modes” .
In this list, some modes are particular and are described
below .
Opacity
The Opacity slider sets the transparency level for the brush
operation. To understand how it works, imagine that instead of
altering the active layer, the tool creates a transparent layer
above the active layer and acts on that layer. Changing Opacity in
the Tool Options has the same effect that changing opacity in the
Layers dialog would have in the latter situation. It controls the
“ strength ” of all paint tools, not just those that
paint on the active layer. In the case of the Eraser, this can
come across as a bit confusing: it works out that the higher the
“ opacity ” is, the more transparency you get.
Brush
The brush determines how much of the image is affected by the
tool, and how it is affected, when you trace out a brushstroke
with the pointer. GIMP allows you to use
several different types of brushes , which are described in the
Brushes
section. The same brush choices are available for all paint tools
except the Ink tool, which uses a unique type of procedurally
generated brush. The colors of a brush only come into play for
tools where they are meaningful: the Pencil, Paintbrush, and
Airbrush tools. For the other paint tools, only the intensity
distribution of a brush is relevant.
Size
This option lets you to modify precisely the size of the brush .
You can use the arrow keys to vary by ±0.01 or the Page-Up and
Page-Down keys to vary by ±1.00. You can obtain the same result if
you have correctly set your mouse-wheel in the Preferences. See
How to vary the
size of a brush
Aspect Ratio
This determines the ratio between the height and the width
of the brush . The slider is scaled from -20.00 to 20.00 with the
default value set to 0.00. A negative value from 0.00 to -20 will
narrow the height of the brush while a positive value between 0.00
and 20.00 indicates the narrowing rate of the width of the brush .
Angle
This option makes the brush turn round its center. This is visible
if the brush is not circular or made from a rotated figure.
Dynamics Figure 14.40. The Brush Dynamics in the Tool Options Dialog
Brush dynamics let you map different brush parameters to several
input dynamics. They are mostly used with graphic tablets, but
some of them are also usable with a mouse.
You can read more about dynamics in
Dynamics
When stroking paths and selections using a paint tool there is a an
option to select “ Emulate brush dynamics ” . That means
that when you stoke, brush pressure and velocity are varying along
the length of the stroke. Pressure starts with zero, ramps up to
full pressure and then ramps down again to no pressure. Velocity
starts from zero and ramps up to full speed by the end of the
stroke.
Dynamics Options
These options are described in
Dynamics Options
Apply Jitter
You know “ spacing ” in brush strokes: strokes are
made of successive brush marks which, when they are very near,
seem to draw a continuous line. Here, instead of being aligned
brush marks are scattered over a distance you can set with the
Amount slider.
Figure 14.41. “ Jitter ” example
From top to bottom: without jitter, jitter = 1, jitter = 4.
Jitter is also available in the Paint Dynamic Editor where you can
connect jitter to the behavior of the brush.
Smooth Stroke
This option doesn't affect the rendering of the brush stroke but
its “ shape ” . It takes away the wobbles of the line you
are drawing. It makes drawing with a mouse easier.
When this option is checked , two setting areas appear,
Quality and Weight . You
can change the default values to adapt them to your skill.
High weight values rigidifies the brush stroke.
Figure 14.42. “ Smooth Stroke ” example
Trying to draw a straight line and a sine curve with the
mouse. 1 : option unchecked 2 : default values
3 : maximum values
Incremental
The incremental check-box does not seems to work as everyone expect.
If it is deactivated (the default value) the maximum effect of a
single stroke is determined by the opacity set in the opacity
slider. If the opacity is set to less than 100, moving the brush
over the same spot will increase the opacity if the brush is lifted
in the meantime. Painting over with the same stroke has no such
effect. If Incremental is active the brush will paint with full
opacity independent of the slider's setting. This option is available
for all paint tools except those which have a “ rate ”
control, which automatically implies an incremental effect. See
also Section 2, “Layer Modes” .
3.1.3. Paint Mode Examples
The following examples demonstrate some of GIMP 's
paint modes:
Dissolve Figure 14.43. Dissolve mode example
Two brush-strokes made with the Airbrush, using the same
fuzzy circular brush. Left: Normal mode. Right: Dissolve
mode.
For any paint tool with opacity less than 100%, this very
useful mode doesn't draw transparency but determines the
probability of applying paint. This gives nice patterns of
dots to paint-strokes or filling.
Figure 14.44. Painting in Dissolve mode
This image has only the background layer and no Alpha
channel. The background color is sky blue. Three
strokes with Pencil and various opacities: 100%, 50%,
25%. Foreground color pixels are scattered along
brushstroke.
Behind Figure 14.45. Example for layer mode “ Behind ” Wilber over a blue background layer Layers dialog Filled with pattern
This mode applies paint only to transparent areas of the
layer : the lower the opacity, the more paint is applied.
Thus, painting opaque areas has no effect; painting
transparent areas has the same effect as normal mode. The
result is always an increase in opacity. Of course none of
this is meaningful for layers that lack an alpha channel.
In the above example image, Wilber is on the top layer,
surrounded by transparency. The lower layer is solid light
blue . The Bucket Fill tool was used, with the
Fill Whole Selection option checked
and the entire layer was selected. A pattern was used to
paint with the Bucket Fill tool .
The next image (below) has two layers. The upper layer is active.
Three brushtrokes with pencil, red color at 100%, 50%, 25%: only
transparent or semi-transparent pixels of the layer are painted.
Figure 14.46. Painting in “ Behind ” mode
Painting with 100%, 50%, 25% transparency (from left to
right)
Color Erase Figure 14.47. Example for layer mode “ Color erase ” Wilber over a blue background layer White foreground color erased
This mode erases the foreground color, replacing it with
partial transparency. It acts like the
Color to Alpha
filter, applied to the area under the brushstroke. Note that
this only works on layers that possess an alpha channel;
otherwise, this mode is identical to Normal.
In the above example image, the color of the Bucket Fill tool
was white, so white parts of Wilber were erased and the blue
background shows through.
This image below has only one layer, the background layer.
Background color is sky blue. Three brushtrokes with
pencil:
With the exact color of the blue area: only this blue color is
erased.
With the exact color of the red area. Only this red color is
erased, whatever its transparency. Erased areas are made
transparent.
With the sky blue color of the layer background: only this
color is erased.
Figure 14.48. Painting in “ Color Erase ” mode
Painted with 1. blue; 2. red; 3. background color
3.1.4. Further Information
Advanced users may be interested to know that paint tools actually
operate at a sub-pixel level, in order to avoid producing jagged-looking
results. One consequence of this is that even if you work with a
hard-edged brush, such as one of the Circle brushes, pixels on the edge
of the brushstroke will only be partially affected. If you need to have
all-or-nothing effects (which may be necessary for getting a good
selection, or for cutting and pasting, or for operating pixel-by-pixel
at a high zoom level ), use the Pencil tool, which makes all brushes
perfectly hard and disables sub-pixel anti-aliasing.
2.8. Foreground Select 3.2. Dynamics
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13. Presets 13. Presets Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. Presets
If you often use tools with particular settings, presets are for you. You
can save these settings and get them back when you want.
Paint tools, which are normally in Toolbox, have a preset system that have
been much improved with GIMP -2.8 . Color tools (except
Posterize and Desaturate), which are not normally in Toolbox, have their
own preset system.
Four buttons at the bottom of all tools options dialogs allow you to save,
restore, delete or reset presets.
Paint tool presets are described in Section 5.1 , “Tool Presets Dialog” .
Color tool presets are described in Section 5.1 .1, “Color Tool Presets” .
12. Palettes 14. Drawing Simple Objects
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2. Selection Tools 2. Selection Tools Chapter 14. Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Selection Tools Figure 14.8. The Selection tools 2.1. Common Features
Selection tools are designed to select regions from the active layer so
you can work on them without affecting the unselected areas. Each tool has
its own individual properties, but the selection tools also share a number
of options and features in common. These common features are described
here; the variations are explained in the following sections for each tool
specifically. If you need help with what a “ selection ”
is in GIMP, and how it works, see
Selection .
There are seven selection tools:
the Rectangle Select ;
the Ellipse Select ;
the
Free Select (the Lasso) ;
the
Select Contiguous Regions (the Magic Wand)
;
the Select by Color ;
the
Select Shapes from Image (Intelligent Scissors)
and
the
Foreground Select .
In some ways the Path tool can also be thought of as a selection tool: any
closed path can be converted into a selection. It also can do a great deal
more, though, and does not share the same set of options with the other
selection tools.
2.1.1. Key modifiers (Defaults)
The behavior of selection tools is modified if you hold down the
Ctrl , Shift , and/or
Alt keys while you use them.
Note
Advanced users find the modifier keys very valuable, but novice users
often find them confusing. Fortunately, it is possible for most
purposes to use the Mode buttons (described below) instead of modifier
keys.
Ctrl
When creating a selection, holding down the
Ctrl key can have two different actions
according to the way you use it:
Holding down the key while drawing
the selection toggles the “ Expand from center ”
option.
If you hold down the Ctrl key
before drawing a selection , this new
selection switches to the Subtract mode. So, this new
selection will be subtracted from an existing one as soon as
you release the click, as far as they have common pixels.
Alt
Holding Alt will allow movement of the
current selection (only its frame, not its content). If the
whole image is moved instead of the selection only, try
Shift + Alt .
Note that the Alt key is sometimes intercepted by
the windowing system (meaning that GIMP never knows that it was
pressed), so this may not work for everybody.
Shift
When creating a selection, holding down the
Shift key can have two different actions
according to the way you use it:
If you hold down the key before
clicking to start the selection, this
selection will be in Addition
mode as long as you press the key.
If you hold down the Shift key
after clicking to start the selection,
the effect will depend on the tool you are using: for
example, the selection will be a square with the
Rectangle Select tool .
Ctrl + Shift
Using
Ctrl + Shift
together can do a variety of things, depending on which tool is
used. Common to all selection tools is that the selection mode
will be switched to intersection, so that after the operation is
finished, the selection will consist of the intersection of the
region traced out with the pre-existing selection. It is an
exercise for the reader to play with the various combinations
available when performing selections while holding
Ctrl + Shift
and releasing either both or either prior to releasing the
mouse button .
Key modifiers to move selections Ctrl + Alt + Click-and-drag and
Shift + Alt + Click-and-drag
are used to move selections.
See Section 2.1, “Moving a Selection” .
Space bar
Pressing the Space Bar while using a selection
tool transforms this tool into the Navigation cross as long as
you press the bar, allowing you to pan around the image instead
of using the scroll-bars when your image is bigger than the
canvas. This is the default option: in Preferences/Image Windows,
you can toggle the Space bar to the Move tool.
2.1.2. Options
Here we describe the tool options that apply to all selection tools:
options that apply only to some tools, or that affect each tool
differently, are described in the sections devoted to the individual
tools. The current settings for these options can be seen in the Tool
Options dialog, which you should always have visible when you are using
tools. To make
the interface consistent, the same options are presented for all
selection tools, even though some of them don't have any effect for some
of the tools.
Figure 14.9. Common options of selection tools Mode
This determines the way that the selection you create is combined
with any pre-existing selection. Note that the functions performed
by these buttons can be duplicated using modifier keys, as
described above. For the most part, advanced users use the
modifier keys; novice users find the mode buttons easier.
Replace mode will cause any existing selection to be
destroyed or replaced when the new selection is created.
Add mode will cause the new selection to be added to any
existing selection regions.
Subtract mode will remove the new selection area from any
existing selection regions.
Intersection mode will make a new selection from the area
where the existing selection region and the new selection
region overlap.
Antialiasing
This option only affects some selection tools: it causes
the boundary of the selection to be drawn more smoothly.
Feather Edges
This options allows the boundary of the selection to be blurred,
so that points near the boundary are only partially selected. For
further information regarding feathering, see the glossary entry
Feathering .
Chapter 14. Tools 2.2. Rectangle Selection
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4. Transform Tools 4. Transform Tools Chapter 14. Tools  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. Transform Tools Figure 14.99. An overview of the transform tools 4.1. Common Features
Inside the Transformation tool dialog, you will find eight tools to modify
the presentation of the image or the presentation of an element of the
image, selection, layer or path. Each transform tool has an Option dialog
and an Information dialog to set parameters.
4.1.1. Tool Options Figure 14.100. Common options of transform tools
Some options are shared by several transform tools. We will describe
them here. More specific options will be described with their tool.
Transform GIMP offers you three buttons which let you
select which image element the transform tool will work on.
Note
Remember that the Transform option persists when you quit the
tool.
When you activate the first button
the tool works on the active layer . If no selection exists in
this layer, the whole layer will be transformed.
When you activate the second button
the tool works on the selection contour only (the whole layer
contour if no selection).
When you activate the third button,
the tool works on the path only.
Direction
This option sets which way or direction a
layer is transformed:
The “ Normal (Forward) ” mode will transform the
image or layer as one might expect. You just use the handles to
perform the transformation you want. If you use a grid (see
below), the image or layer is transformed according to the
shape and position you put the grid into.
“ Corrective (Backward) ” inverts the direction.
Primarily used with the Rotation tool to repair digital images
that have some geometric errors (a horizon not horizontal, a wall
not vertical...). See Section 4.5, “Rotate” .
Interpolation
This drop-down list lets you choose the method and thus the
quality of the transformation:
None
The color of each pixel is copied from its closest
neighboring pixel in the original image. This often results
in aliasing (the “ stair-step ” effect) and a
coarse image, but it is the fastest method. Sometimes this
method is called “ Nearest Neighbor ” .
Linear
The color of each pixel is computed as the average color of
the four closest pixels in the original image. This gives a
satisfactory result for most images and is a good compromise
between speed and quality. Sometimes this method is called
“ Bilinear ” .
Cubic
The color of each pixel is computed as the average color of
the eight closest pixels in the original image. This usually
gives a good result, but it naturally takes more time.
Sometimes this method is called “ Bicubic ” .
Sinc (Lanczos3)
The Lanczos3 method uses the Sinc mathematical function and
performs a high quality interpolation. This is usually the
best method but if you are not satisfied with the result,
you may give “ Cubic ” a try.
You can set the default interpolation method in the
Tools Options
Preferences dialog.
Clipping
After transformation, the image can be bigger. This option will
clip the transformed image to the original image size.
You can choose between several ways to clip: Adjust Figure 14.101. Original image for examples Original image
Rotation applied with “ Adjust ”
Rotation applied with “ Adjust ”
and canvas enlarged to layer size
With Adjust: the layer is enlarged to contain all the
rotated layer. The new layer border is visible; the whole
layer becomes visible by using the
Image → Fit Canvas to Layers
command .
Clip Figure 14.102. Example for Clip Clip
With Clip: all what exceeds image limits is deleted.
Crop to result Figure 14.103. Example for Crop to result Rotation 45° with Crop to result
The crop limit is marked with red. No transparent
area is included.
If this option is selected, the image is cropped so that
the transparent area, created by the transform operation
in corners, will not be included in the resulting image.
Crop with aspect Figure 14.104. Example for Crop with aspect Original image Rotation -22° The rotated image
This option works like the one described before, but makes
sure, that the aspect ratio is maintained.
Preview
If this is marked, which is the default setting, the transformed
image will be visible on top of the original image or layer. There
will also be a slider with which you may select the preview opacity.
Guides
This is a drop down list where you select the type of guide lines
which suits your transforming. All the guides uses a frame to mark
the image's outline in addition to the lines used by the different
selections.
No guides
As the name tells you, there are no guides used.
Center lines
Uses one vertical line and one horizontal line crossing each
other in the center of the image or layer.
Rule of thirds
Divides the transforming area in nine equal parts by adding
two horizontal lines and two vertical lines equally spaced.
According to this rule the most interesting parts of the image
should be placed at the intersection points.
Rule of fifths
Just as the “ Rules of thirds ” but divides the area in five by
five parts.
Golden sections
Also called “ The Golden Ratio ” . This divides the
transforming area in nine parts using a mathematical formula
proportioning the parts to each others and to the area to be
transformed.
Diagonal lines
Divide the transforming area using diagonally lines.
Number of lines
Puts a rectangular grid with equal numbers of vertically
and horizontally lines. The number of lines is set in the
slider popping up when this guide is selected.
Line spacing
Puts a rectangular grid on the transforming area using the
spacing between the lines set in the slider.
4.1.2. Transforming Paths
If you for some reason want to transform paths, it is possible to do
this using the transform tools.
Figure 14.105. Rotating paths Paths dialog Option modus: Path
When the path is drawn go to the path dialog and click on the first field
before the path outline in the dialog window to get the eye icon visible.
Then choose the transformation tool and in the upper part of the option
dialog click on the path icon to tell the tool to act on the path.
Do the transformation the usual way and confirm it when finished. It
could be a good idea to set the Guides to “ No guides ” to get
the path more recognizable.
When the transformation is finished, choose the path tool and click on
the changed path to activate it again for further working on it.
3.16. Dodge/Burn 4.2. Align
 Report an error in Bugzilla 
Chapter 14. Tools Chapter 14. Tools Part III. Function Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 14. Tools Table of Contents 1. The Toolbox 1.1. Introduction 1.2. Tool Icons 1.3. Color and Indicator Area 1.4. Tool Options 2. Selection Tools 2.1. Common Features 2.2. Rectangle Selection 2. 3. Ellipse Selection 2.4. Free Selection (Lasso) 2.5. Fuzzy selection (Magic wand) 2. 6. Select By Color 2.7. Intelligent Scissors 2. 8. Foreground Select 3. Paint Tools 3.1. Common Features 3.2. Dynamics 3.3. Brush Tools (Pencil, Paintbrush, Airbrush) 3.4. Bucket Fill 3. 5. Blend 3.6. Pencil 3.7. Paintbrush 3.8. Eraser 3.9. Airbrush 3.10. Ink 3.11. Clone 3.12. Heal 3.13. Perspective Clone 3. 14. Blur/Sharpen 3.15. Smudge 3.16. Dodge/Burn 4. Transform Tools 4.1. Common Features 4.2. Align 4.3. Move 4.4. Crop 4.5. Rotate 4.6. Scale 4.7. Shear 4.8. Perspective 4.9. Flip 4.10. The Cage Tool 5. Color Tools 5.1. Overview 5.2. Color Balance 5. 3. Hue-Saturation 5.4. Colorize 5.5. Brightness-Contrast 5. 6. Threshold 5.7. Levels 5.8. Curves 5.9. Posterize 5.10. Desaturate 6. Other 6.1. Overview 6.2. Paths 6.3. Color Picker 6.4. Zoom 6.5. Measure 6.6. Text 6.7. GEGL Operation 1. The Toolbox 1.1. Introduction GIMP provides a comprehensive toolbox in order to
quickly perform basic tasks such as making selections or drawing paths.
The many tools contained within GIMP 's toolbox are
discussed in detail here.
(In case you're curious, in GIMP lingo a "tool" is a
way of acting on an image that requires access to its display, either to
let you indicate what you want to do by moving the pointer around inside
the display, or to show you interactively the results of changes that
you have made. But if you want to think of a tool as a saw, and an image
as a piece of wood, it probably won't do you a great deal of harm.)
Note
See Main Windows: The
Toolbox for an overview of the toolbox and its components.
GIMP has a diverse assortment of tools that let you
perform a large variety of tasks. The tools can be thought of as falling
into five categories:
Selection tools , which specify or modify the
portion of the image that will be affected by subsequent actions;
Paint tools , which alter the colors in some
part of the image;
Transform tools , which alter the geometry of
the image;
Color tools , which alter the distribution of
colors across the entire image;
Other tools , which don't fall into the other
four categories.
1.2. Tool Icons Figure 14.1. The Tool Icons in the Toolbox
Most tools can be activated by clicking on an icon in the Toolbox. By
default , some tools are accessible only via the menus (namely the Color
tools are accessible only either as
Colors
or as
Tools → Colors ).
Every tool, in fact, can be activated from the
Tools menu; also, every tool can be activated from
the keyboard using an accelerator key.
In the default setup, created when GIMP is first
installed, not all tools show icons in the Toolbox: the Color tools are
omitted. You can customize the set of tools that are shown in the
Toolbox through
Edit → Preferences → Toolbox .
There are two reasons you might want to do this : first, if you only
rarely use a tool, it might be easier to find the tools you want if the
distracting icon is removed; second, if you use the Color tools a lot,
you might find it convenient to have icons for them easily available. In
any case, regardless of the Toolbox, you can always access any tool at
any time using the Tools menu from an image menubar.
The shape of the cursor changes when it is inside an image, to one that
indicates which tool is active (if in Preferences you
have set
Image Windows → Mouse Pointers → Pointer mode → Tool icon ).
1.3. Color and Indicator Area Figure 14.2. Color and Indicator Area in the Toolbox 1.3.1. Color Area Figure 14.3. Active Colors in the Toolbox Color area
This area shows GIMP's basic palette, consisting of two colors,
the Foreground and Background, used for painting, filling, and
many other operations. Clicking on either of the color displays
brings up a Color Editor dialog, which permits you to change it.
Default colors
Clicking on this small symbol resets the Foreground and Background
colors to black and white, respectively. Pressing the
D key has the same effect .
Swap FG/BG colors
Clicking on the small curved line with two arrowheads causes
the Foreground and Background colors to be swapped. Pressing the
X key has the same effect .
Tip
You can click-and-drag one of these colors directly into a layer: it
will fill the whole layer.
1.3.2. Tools Indicator Area Figure 14.4. Active Brush, Pattern and Gradient in the Toolbox
This part of the Toolbox shows the currently selected brush, pattern,
and gradient. Clicking on any of them brings up a dialog that allows you
to change it.
1.3.3. Active Image Area Figure 14.5. Active Image in the Toolbox
A thumbnail of the active image can be displayed in this area if the
“ Display Active Image ” option is checked in
Preferences/Toolbox. If you click on this thumbnail, the
“ Images ” dialog is opened, useful if you have many
images on your screen. You can also click and drag this thumbnail to an
enabled XDS [9]
file manager to directly save the corresponding image.
1.4. Tool Options Figure 14.6. Tool Options Dialog
The Tool Options dialog of the Airbrush tool.
If you have things set up like most people do, activating a tool causes
its Tool Options dialog to appear below the Toolbox. If you don't have
things set up this way, you probably should: it is very difficult to use
tools effectively without being able to manipulate their options.
Tip
The Tool Options appear beneath the Toolbox in the default
setup. If you lose it somehow, you can get it back by creating
a new Tool Options dialog using
Windows → Dockable Dialogs → Tool Options
and then docking it below the Toolbox. See the section on
Dialogs and Docking if you
need help.
Each tool has its own specific set of options. The choices you make for
them are kept throughout the session, until you change them. In fact,
the tool options are maintained from session to session. The persistence
of tool options across sessions can sometimes be an annoying nuisance: a
tool behaves very strangely, and you can't figure out why until you
remember that you were using some unusual option the last time you
worked with it, two weeks ago.
At the bottom of the Tool Options dialog , four buttons appear:
Save Options to
This button allows you to save the settings for the current tool,
so that you can restore them later. It brings up the Section 5.1, “Tool Presets Dialog”
allowing you to give a name for the new preset. When
you Restore options, only saved presets for the active tool are
shown, so you need not worry about including the name of the tool
when you assign a name here.
Restore Options
This button allows you to restore a previously saved preset of
options for the active tool. If no presets have ever been
saved for the active tool, the button will be insensitive.
Otherwise, clicking it will bring up a menu showing the names of
all saved option sets: choosing a menu entry will apply those
settings.
Delete Options
This button allows you to delete a previously saved set of options
for the active tool. If no option-sets have ever been saved for
the active tool, the button will simply repeat the tool name.
Otherwise, clicking it will bring up a menu showing the names of all
saved presets: the selected preset will be deleted.
Reset Options
This button resets the options for the active tool to their
default values.
New sliders
Option sliders have changed with GIMP-2.8: it is not visible, but
the slider area is now divided into upper and lower parts.
Figure 14.7. The new sliders of tool options dialogs
The upwards arrow pointer in the top half of the slider area
The horizontal two-way arrow pointer in the lower half of
the slider area In the top half of the slider area :
Clicking with the up arrow pointer sets slider to a value that
depends on the position of the pointer (no reference,
imprecise).
Clicking and dragging the up arrow pointer sets the value by
large amounts.
In the lower half of the slider area :
Clicking with the two-way arrow pointer has no effect.
Clicking and dragging the two-way arrow pointer sets the value
by small amounts.
Once you have set the value approximately, you can tune it precisely
using the two small arrow buttons at the right of the slider.
The value area in the slider area works as a text editor: there, you
can edit the value or enter a new value directly.
For some options, you can drag the pointer outside the tool dialog.
For example with the size slider, whose maximum value is 10,000,
you can drag the mouse pointer up to the right side of your screen.
[9]
See [ XDS ] .
Part III. Function Reference 2. Selection Tools
 Report an error in Bugzilla  4. 7. Change the Mode 4. 7. Change the Mode 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 7. Change the Mode As with anything else, images come in different kinds and serve
different purposes. Sometimes, a small size is important (for web sites)
and at other times, retaining a high color depth (e.g., a family portrait)
is what you want.
GIMP can handle all of this, and more, primarily by
converting between three fundamental modes, as seen in this menu. In order
to switch your image to one of these modes, you open it and follow that
menu and click the mode you want. Figure 3.32. Dialog for changing the mode RGB - This is the default mode, used for high-quality
images, and able to display millions of colors. This is also the mode for
most of your image work including scaling, cropping, and even flipping. In
RGB mode, each pixel consists of three different components: R- & gt;Red,
G- & gt;Green, B- & gt;Blue. Each of these in turn can have an intensity value
of 0-255. What you see at every pixel is an additive combination of these
three components. Indexed - This is the mode usually used when file size
is of concern, or when you are working with images with few colors. It
involves using a fixed number of colors (256 or less) for the entire image
to represent colors. By default, when you change an image to a palleted
image, GIMP generates an “ optimum palette ”
to best represent your image. Figure 3.33. Dialog
“ Change to Indexed Colors ” As you might expect, since the information needed to represent the
color at each pixel is less, the file size is smaller. However, sometimes,
there are options in the various menus that are grayed-out for no apparent
reason. This usually means that the filter or option cannot be applied when
your image is in its current mode. Changing the mode to RGB, as outlined
above, should solve this issue. If RGB mode doesn't work either, perhaps
the option you're trying requires your layer to have the ability to be
transparent. This can be done just as easily via
Layer → Transparency → Add Alpha Channel . Figure 3.34. Add Alpha Channel Grayscale - Grayscale images have only shades of gray.
This mode has some specific uses and takes less space on the hard drive in
some formats, but is not recommended for general use as reading it is not
supported by many applications. There is no need to convert an image to a specific mode before saving
it in your favorite format, as GIMP is smart enough to
properly export the image. 4.6. Find Info About Your Image 4.8. Flip An Image  Report an error in Bugzilla  4. 5. Crop An Image 4. 5. Crop An Image 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 5. Crop An Image Figure 3.27. Example Image for Cropping Source image Image after cropping There are many reasons to crop an image; for example, fitting an
image to fill a frame, removing a portion of the background to emphasize
the subject, etc. There are two methods to activate the crop tool. Click
the
button in the Toolbox, or use
Tools → Transform Tools → Crop in the image window. This changes the cursor and allow you to
click and drag a rectangular shape. The button in the toolbox is the
easiest way to get to any of the tools. Figure 3.28. Select a Region to Crop Click on one corner of the desired crop area and drag your mouse to
create the crop rectangle. You don't have to be accurate as you can change
the exact shape of the rectangle later. Figure 3.29. Dialog for Cropping After completing the click and drag motion, a rectangle with special
regions is shown on the canvas. As the cursor is moved over the different
areas of the selected crop area, the cursor changes. You can then drag the
rectangle's corners or edges to change the dimensions of the selected area.
As shown in the figure above , as the crop area is resized, the dimensions
and ratio are shown in the status bar. See
Section 4.4, “Crop” for more information on cropping in
GIMP . If you would like to crop the image in a specific
aspect ratio, such as a square, make sure the tool options are visible (
Windows → Dockable Dialogs → Tool Options ). In the Tool Options dockable , check the mark next to
Fixed and make sure the drop-down box next to it is
set to Aspect Ratio . You can now type the desired
aspect ratio on the text box below, such as “ 1:1 ” . You also
have controls to change the aspect from landscape to portrait. After you
set the aspect ratio, drag one of the corners of the crop rectangle to
update it. The rectangle changes to the chosen ratio, and when you drag
it should maintain that ratio. 4.4. Compressing Images 4. 6. Find Info About Your Image
 Report an error in Bugzilla  4.8. Flip An Image 4. 8. Flip An Image 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 8. Flip An Image Use this option when you need the person in the photo looking in the
other direction, or you need the top of the image to be the bottom. Use
Tools → Transform Tools → Flip , or use the
button on the toolbox. After selecting the flip tool from the
toolbox, click inside the canvas. Controls in the Tool Options dockable let
you switch between Horizontal and Vertical modes. Figure 3.35. Dialog
“ Flip an Image ” After selecting the flip tool from the toolbox, click inside the
canvas. The tool flips the image horizontally. Use the options dialog to
switch between horizontal and vertical. If it is not already displayed in
the dock under the toolbox, double click the toolbox button. You can also
use the Ctrl key to switch between
horizontal and vertical. In the images below, all possible flips are demonstrated: Figure 3.36. Example Image to Flip Source image Horizontal flipped image Vertical flipped image Horizontal and vertical flipped image 4.7. Change the Mode 4. 9. Rotate An Image
 Report an error in Bugzilla  4. 6. Find Info About Your Image 4.6. Find Info About Your Image 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 6. Find Info About Your Image Figure 3.30. Finding Info When you need to find out information about your image, Use
Image → Image Properties to open the “ Image Properties ” dialog,
which contains information about the image size, resolution, mode
and much more. Figure 3.31. “ Image Properties ” Dialog 4.5. Crop An Image 4. 7. Change the Mode  Report an error in Bugzilla 
4. 4. Compressing Images 4. 4. Compressing Images 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 4. Compressing Images Figure 3.21. Example Image for JPEG Saving If you have images that take up a large space on disk, you can reduce
that space even without changing the image dimensions. The best image
compression is achieved by using the JPG format, but
even if the image is already in this format, you can usually still make it
take up less space, as the JPG format has an adaptive compression
scheme that allows saving in varying levels of compression. The trade-off
is that the less space an image takes, the more detail from the original
image you lose. You should also be aware that repeated saving in the JPG
format causes more and more image degradation.
To save you image as a JPG file, therefore, use
File → Save As to open the “ Save As ” dialog. Figure 3.22. “ Save As ” Dialog The dialog opens with the file name already typed in the Name box.
If the image is not a JPG image, delete the existing
extension and type JPG instead, and GIMP will determine
the file type from the file extension. Use the file extension list,
circled in the figure above, to see the types supported by
GIMP . The supported extensions change depending on your
installed libraries. If GIMP complains, or if
“ JPEG ” is grayed out in the Extensions menu, cancel out of
everything and step through the
Section 4.7, “Change the Mode” . Once you have done
this, click Save . This opens the “ Save as"
” JPEG dialog that contains the quality control. The “ Save as JPEG ” dialog uses default values that
reduce size while retaining good visual quality; this is the safest and
quickest thing to do. Figure 3.23. “ Save as JPEG ” dialog with poor quality. Reduce the image Quality to make the image even
smaller. Reduced quality degrades the image, so be certain to check
“ Show preview in image window ” to visually gauge the
degradation. As shown in the figure above , a Quality
setting of 10 produces a very poor quality image that uses very little
disk space. The figure below shows a more reasonable image. A quality of
75 produces a reasonable image using much less disk space, which will, in
turn, load much faster on a web page. Although the image is somewhat
degraded, it is acceptable for the intended purpose. Figure 3.24. Dialog for Image Saving as JPEG Finally, here is a comparison of the same picture with varying
degrees of compression: Figure 3.25. Example for High JPEG Compression Quality: 10; Size: 3.4 KiloBytes Quality: 40; Size: 9.3 KiloBytes Figure 3.26. Example for Moderate JPEG Compression Quality: 70; Size: 15.2 KiloBytes Quality: 100; Size: 72.6 KiloBytes 4.3. Change the Size of an Image for print 4.5. Crop An Image  Report an error in Bugzilla  4. 9. Rotate An Image 4.9. Rotate An Image 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 9. Rotate An Image Figure 3.37. Menu for
“ Rotate An Image ” Images that are taken with digital cameras sometimes need to be
rotated. To do this, use
Image → Transform → Rotate 90° clockwise (or counter-clockwise ). The images below demonstrate a 90
degrees CCW rotation. Figure 3.38. Example for
“ Rotate An Image ” Source Image Rotated image 90 degree CCW 4.8. Flip An Image 4. 10. Separating an Object From Its Background  Report an error in Bugzilla 
4. 3. Change the Size of an Image for print 4.3. Change the Size of an Image for print 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 3. Change the Size of an Image for print As discussed before, pixels don't have a set size in the real world.
When you set out to print an image on paper,
GIMP needs to know how big each pixels is. We use a
parameter called resolution to set the ratio between pixels and real-world
units such as inches. By default, most images open with the resolution set to 72. This
number was chosen for historical reasons as it was the resolution of
screens in the past, and means that when printed, every pixel is 1/72 of an
inch wide. When printing images are taken with modern digital cameras, this
produces very large but chunky images with visible pixels. What we want to
do is tell GIMP to print it with the size we have in
mind, but not alter the pixel data so as not to lose quality. To change the print size use
Image → Print Size to open the “ Print Size ” dialog. Select a size
unit you are comfortable with, such as “ inches ” . Set one
dimension, and let GIMP change the other one
proportionally. Now examine the change in resolution. If the resolution is
300 pixels per Inch or over, the printed image's quality will be very high
and pixels will not be noticeable. With a resolution of between 200 and
150 ppi, pixels will be somewhat noticeable, but the image will be fine as
long as its not inspected too closely. Values lower than 100 are visibly
coarse and should only be used for material that is seen from a distance,
such as signs or large posters. Figure 3.20. Dialog for Setting Print Size 4.2. Change the Size of an Image for the screen 4. 4. Compressing Images
 Report an error in Bugzilla  4. 2. Change the Size of an Image for the screen 4. 2. Change the Size of an Image for the screen 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 2. Change the Size of an Image for the screen You have a huge image, possibly from a digital camera, and you want
to resize it so that it displays nicely on a web page, online board or
email message. Figure 3.17. Example Image for Scaling The first thing that you might notice after opening the image, is
that
GIMP opens the image at a logical size for viewing. If
your image is very large , like the sample image,
GIMP sets the zoom so that it displays nicely on the
screen. The zoom level is shown in the status area at the bottom of the
Image window . This does not change the actual image. The other thing to look at in the title-bar is the mode. If the mode
shows as RGB in the title bar, you are fine. If the mode says
Indexed or Grayscale , read the
Section 4.7, “Change the Mode” . Figure 3.18. GIMP Used for Image Scaling Use
Image → Scale Image to open the “ Scale Image ” dialog. You can right
click on the
image to open the menu, or use the menu along the top of the Image window.
Notice that the “ Scale Image ” menu item contains three dots,
which is a hint that a dialog will be opened. Figure 3.19. Dialog for Image Scaling in Pixels The unit of size for the purpose of displaying an image on a screen
is the pixel. You can see the dialog has two sections: one for
width and
height and another for
resolution . Resolution applies to
printing only and has no effect on the image's size when it is displayed on
a monitor or a mobile device. The reason is that different devices have
different pixels sizes and so, an image that displays on one device (such
as a smartphone) with a certain physical size, might display on other
devices (such as an LCD projector) in another size altogether. For the
purpose of displaying an image on a screen , you can ignore the resolution
parameter. For the same reason, do not use any size unit other than the
pixel in the height / width fields. If you know the desired width, enter it in the dialog at the top
where it says
Width . This is shown in the figure
above . If you don't have such a number in mind, choose an appropriate width
for the desired use. Common screen sizes range between 320 pixels for
simpler phones, 1024 pixels for a netbook, 1440 for a wide-screen PC
display and 1920 pixels for an HD screen. for the purpose of displaying an
image on -line, a width of 600 to 800 pixels offers a good
compromise. When you change one of the image's dimensions,
GIMP changes the other dimension proportionally. To
change the other dimension, see
Section 4.5, “Crop An Image” . Bear in mind that when you
change the two dimensions arbitrarily, the image might become stretched or
squashed. 4. Common Tasks 4.3. Change the Size of an Image for print
 Report an error in Bugzilla 
4. 10. Separating an Object From Its Background 4.10. Separating an Object From Its Background 4. Common Tasks  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 10. Separating an Object From Its Background Figure 3.39. Object with Background Sometimes you need to separate the subject of an image from its
background. You may want to have the subject on a flat color, or keep the
background transparent so you can use it on an existing background, or any
other thing you have in mind. To do this, you must first use
GIMP 's selection tools to draw a selection around your
subject. This is not an easy task, and selecting the correct tool is
crucial. You have several tools to accomplish this. The “ Free Select Tool ” allows you to draw a border
using either freehand or straight lines. Use this when the subject has a
relatively simple shape. Read more about this tool here:
Section 2. 4, “Free Selection (Lasso)” Figure 3.40. Free Select Tool The “ Intelligent Scissors Select Tool ” lets you select
a freehand border and uses edge-recognition algorithms to better fit the
border around the object. Use this when the subject is complex but
distinct enough against its current background. Read more about this tool
here: Section 2. 7, “Intelligent Scissors” Figure 3.41. Intelligent Scissors Select Tool The “ Foreground Select Tool ” lets you mark areas as
“ Foreground ” or “ Background ” and refines the
selection automatically. Read more about this tool here:
Section 2. 8, “Foreground Select” Figure 3.42. Foreground Select Tool Once you have selected your subject successfully, use
Select → Invert . Now, instead of the subject, the background is selected.
What you do now depends on what you intended to do with the
background. To fill the background with a single color:
Click the foreground color swatch (the top left of the two overlapping
colored rectangles) in the toolbox and select the desired color. Next,
use Section 3.4, “Bucket Fill” to replace the background
with your chosen color.
Figure 3.43. Result of Adding a Plain Color Background To make a transparent background: Use
Layer → Transparence → Add Alpha Channel to add an alpha channel . Next, use
Edit
Clear or hit the
Del key on the keyboard to remove the
background. Please note that only a small subset of file formats
support transparent areas. Your best bet is to save your image as
PNG. Figure 3.44. Result of Adding a Transparent Background To make a black-and-white background while keeping the subject in
color: Use
Colors → Desaturate . In the dialog that opens, cycle between the modes and
select the best-looking one, then click OK. Figure 3.45. Result of Desaturating the Background 4.9. Rotate An Image 5. How to Draw Straight Lines  Report an error in Bugzilla 
4. Common Tasks 4. Common Tasks Chapter 3. First Steps with Wilber  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. Common Tasks This tutorial is based on text Copyright © 2004
Carol Spears. The original tutorial can be found online:
[ TUT02 ] . 4.1. Intention GIMP is a powerful image editing program with many
options and tools. However, it is also well suited for smaller tasks. The
following tutorials are meant for those who want to achieve these common
tasks without having to learn all the intricacies of GIMP
and computer graphics in general. Hopefully, these tutorials will not only help you with your current
task, but also get you ready to learn more complex tools and methods later,
when you have the time and inspiration. All you need to know to start this tutorial, is how to find and open
your image. (
File → Open from the Image window). 3. Undoing 4.2. Change the Size of an Image for the screen  Report an error in Bugzilla  5. 2. Examples 5.2. Examples 5. How to Draw Straight Lines  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 2. Examples Figure 3.53. Examples I
Check Use color from gradient.
Select the Clone tool and set the source to
“ Maple Leaves ” pattern.
Figure 3.54. Examples II
Use
Filters → Render → Pattern → Grid
to create a grid. Use the Smudge Tool to draw a line with a
slightly larger brush.
Use
Filters → Render → Clouds → Plasma
to create the cool plasma cloud. Use the Erase Tool with
a square brush to draw a line.
Figure 3.55. Example III
Use the rectangle select tool to select a rectangle, and then
fill the selection with a light blue color.
Select the dodge/burn tool.
Set the type to Dodge and paint along the top and left side using
an appropriately sized brush. Set the type to Burn and paint along
the right and bottom.
5. How to Draw Straight Lines Chapter 4. Getting Unstuck
 Report an error in Bugzilla  5. How to Draw Straight Lines 5. How to Draw Straight Lines Chapter 3. First Steps with Wilber  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. How to Draw Straight Lines This tutorial is based on Text and images Copyright © 2002 Seth Burgess. The original tutorial can be found in the Internet
[ TUT01 ] .
5.1. Intention Figure 3.46. Example of straight lines
This tutorial shows you how to draw straight lines with
GIMP . Forcing a line to be straight is a
convenient way to deal with the imprecision of a
mouse or tablet, and to take advantage of the power of a computer to
make things look neat and orderly. This tutorial doesn't use Straight
Lines for complex tasks; its intended to show how you can use it to
create quick and easy straight lines.
Preparations Figure 3.47. Introducing the Shift -key
The invention called the typewriter introduced the
Shift
Key. You generally have 2 of them on your keyboard. They look
something like the figure above. The keys are located on the left
and right sides of your keyboard. The mouse
was invented by Douglas C. Engelbart in 1970. These come in
different varieties, but always have at least one button.
Creating a Blank Drawable Figure 3.48. New image
First, create a new image. Any size will do. Use
File → New
to create a new image .
Choose a Tool Figure 3.49. Paint tools in the toolbox
Any of the red-highlighted tools on the above toolbox can do lines.
Create a Starting Point Figure 3.50. Starting point
Click on the paintbrush in the toolbox.
Click in the image where you want a line to start or end. A
single dot will appear on the screen. The size of this dot
represents the current brush size, which you can change in the Brush
Dialog (see Section 3.2, “Brushes Dialog” ).Now, lets start
drawing a line. Hold down the Shift key, and
keep it down.
Drawing the Line Figure 3.51. Drawing the line
After you have a starting point and
while pressing the Shift , you will see a straight
line that follows the cursor.
Press the first button on the Mouse (the leftmost
one usually) and let it go. During that whole
“ click ” of the Mouse button ,
you need to keep the Shift Key held down.
Final Figure 3.52. Final Image
This is a powerful feature. You can draw straight lines with any of
the draw tools. You can even draw more lines at the end of this one.
Our last step is to let go of the Shift key. And
there you have it. Some more examples are shown below. Happy
GIMP ing!
4.10. Separating an Object From Its Background 5.2. Examples
 Report an error in Bugzilla 
2. 7. Undo History Dialog 2.7. Undo History Dialog 2. Image Structure Related Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 7. Undo History Dialog Figure 15.22. The Undo History dialog
This dialog shows you a list of the actions you have most recently
performed on an image, with a small sketch that attempts to illustrate the
changes produced by each. You can revert the image to any point in its
Undo History simply by clicking on the right entry in the list. For more
information on GIMP's Undo mechanism and how it works, see the section on
Undoing .
 2. 7. 1. Activating the dialog
The “ Undo History ” dialog is a dockable dialog; see the
section Section 2.3, “Dialogs and Docking” for help on manipulating
it.
You can access it:
from the image menu:
Windows → Dockable Dialogs → Undo History .
from the Tab menu in any dockable dialog by clicking on
and selecting
Add Tab → Undo History .  2.7.2. Using the Undo History dialog
The most basic thing you can do is to select a point in the Undo History by clicking on it in the list . You can go back and forth between states
in this way as much as you please, without losing any information or
consuming any resources. In most cases, the changes are very fast.
Tip Ctrl + F
opens a search field.
See View as List; View as Grid At the bottom of the dialog are three buttons: Undo
This button has the same effect as choosing
Edit → Undo
from the menu, or pressing
Ctrl + Z ;
it reverts the image to the next state back in the undo history.
Redo
This button has the same effect as choosing
Edit → Redo
from the menu, or pressing
Ctrl + Y ;
it advances the image to the next state forward in the Undo History.
Clear Undo History
This button removes all contents from the undo history except the
current state. If you press it, you are asked to confirm that you
really want to do this. The only reason for doing it would be if
you are very constrained for memory.
Note
In a tab, this dialog is represented by
Note
You can set the number of undo levels in Preferences/Environment .
2.6. Navigation Dialog 3. Image-content Related Dialogs  Report an error in Bugzilla  8. The GIH Dialog Box 8. The GIH Dialog Box Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. The GIH Dialog Box
When your new animated brush is created, it is displayed within the image
window and you would like save it into a gih format. You select
File → Save as...
menu, name your work with the gih extension in the new window relevant
field and as soon as you pressed the Save button, the following window is
displayed:
Figure 7.18. The dialog to describe the animated brush
This dialog box shows up, if you save an image as GIMP image hose
This dialog box has several options not easy to understand. They allow you
to determine the way your brush is animated.
Spacing (Percent) “ Spacing ” is the distance between consecutive brush
marks when you trace out a brushstroke with the pointer. You must
consider drawing with a brush, whatever the paint tool, like
stamping. If Spacing is low, stamps will be very close and stroke
look continuous. If spacing is high, stamps will be separated:
that's interesting with a color brush (like “ green
pepper ” for instance). Value varies from 1 to 200 and this
percentage refers to brush “ diameter ” : 100% is one
diameter.
Description
It's the brush name that will appear at the top of Brush Dialog
(grid mode) when the brush is selected.
Cell Size
That's size of cells you will cut up in layers... Default is one
cell per layer and size is that of the layer. Then there is only
one brush aspect per layer.
We could have only one big layer and cut up in it the cells that
will be used for the different aspects of the animated brush.
For instance, we want a 100x100 pixels brush with 8 different
aspects. We can take these 8 aspects from a 400x200 pixels layer,
or from a 300x300 pixels layer but with one cell unused.
Number of cells
That's the number of cells (one cell per aspect) that will be cut
in every layer. Default is the number of layers as there is only
one layer per aspect.
Display as
This tells how cells have been arranged in layers. If, for example,
you have placed height cells at the rate of two cells per layer on
four layers, GIMP will display:
1 rows of 2 columns on each layer .
Dimension, Ranks, Selection
There things are getting complicated! Explanations are necessary to
understand how to arrange cell and layers.
GIMP starts retrieving cells from each layer and stacks them into a
FIFO stack (First In First Out: the first in is at the top of the
stack and so can be first out). In our example 4 layers with 2 cells
in each, we'll have, from top to bottom: first cell of first layer,
second cell of first layer, first cell of second layer, second cell
of second layer..., second cell of fourth layer. With one cell per
layer or with several cells per layer, result is the same. You can
see this stack in the Layer Dialog of the resulting
.gih image file.
Then GIMP creates a computer array from this stack with the
Dimensions
you have set. You can use four dimensions.
In computer science an array has a “ myarray(x,y,z) ”
form for a 3 dimensions array (3D). It's easy to imagine a 2D array:
on a paper it's an array with rows and columns
With a 3d array we don't talk rows and columns but
Dimensions and
Ranks .
The first dimension is along x axis, the second dimension along y
axis, the third along z axis. Each dimension has ranks of cells.
To fill up this array, GIMP starts retrieving cells from the top of
stack. The way it fills the array reminds that of an odometer: right
rank digits turn first and, when they reach their maximum, left rank
digits start running. If you have some memories of Basic programming
you will have, with an array(4,2,2), the following succession:
(1,1,1),(1,1,2),(1,2,1),(1,2,2),(2,1,1),(2,1,2),(2,2,2),(3,1,1)....
(4,2,2). We will see this later in an example.
Besides the rank number that you can give to each dimension, you can
also give them a Selection mode. You have
several modes that will be applied when drawing:
Incremental GIMP selects a rank from the concerned
dimension according to the order ranks have in that dimension.
Random GIMP selects a rank at random from the
concerned dimension.
Angular GIMP selects a rank in the concerned
dimension according to the moving angle of the brush.
The first rank is for the direction 0°, upwards. The other
ranks are affected, clockwise, to an angle whose value
is 360/number of ranks. So, with 4 ranks in the concerned
dimension, the angle will move 90° clockwise for each
direction change: second rank will be affected to 90°
(rightwards), third rank to 180° (downwards) and fourth rank to
270° (-90°) (leftwards). [2]
Speed, Pressure, x tilt, y tilt
These options are for sophisticated drawing tablets.
Examples A one dimension image pipe
Well! What is all this useful for? We'll see that gradually with
examples. You can actually place in each dimension cases that will
give your brush a particular action.
Let us start with a 1D brush which will allow us to study selection
modes action. We can imagine it like this:
Follow these steps:
Open a new 30x30 pixels image, RGB with Transparent fill type.
Using the Text tool create 4 layers “ 1 ” ,
“ 2 ” , “ 3 ” , “ 4 ” . Delete the
“ background ” layer.
Save this image first with
.xcf extension to keep
its properties then save it as
.gih .
The Save As Dialog is opened: select a destination for your
image. OK. The GIH dialog is opened: Choose Spacing 100, give a
name in Description box, 30x30 for Cell Size, 1 dimension,
4 ranks and choose “ Incremental ” in Selection box.
OK.
You may have difficulties to save directly in the GIMP Brush
directory. In that case, save the
.gih file manually into
the /usr/share/gimp/gimp/2.0/brushes
directory. Then come back into the Toolbox, click in the brush
icon to open the Brush Dialog then click on
Refresh
icon button. Your new brush appears in the
Brush window. Select it. Select pencil tool for instance and
click and hold with it on a new image:
You see 1, 2, 3, 4 digits following one another in order.
Take your .xcf image file
back and save it as .gih
setting Selection to “ Random ” :
Digits will be displayed at random order.
Now select “ Angular ” Selection:
A 3 dimensions image hose
We are now going to create a 3D animated brush: its orientation will
vary according to brush direction, it will alternate Left/Right
hands regularly and its color will vary at random between black and
blue.
The first question we have to answer to is the number of images that
is necessary. We reserve the first dimension (x) to the brush
direction (4 directions). The second dimension (y) is for Left/Right
alternation and the third dimension (z) for color variation. Such a
brush is represented in a 3D array “ myarray(4,2,2) ” :
There are 4 ranks in first dimension (x), 2 ranks in second
dimension (y) and 2 ranks in third dimension (z). We see that there
are 4x2x2 = 16 cells. We need 16 images.
Creating images of dimension 1 (x)
Open a new 30x30 pixels image, RGB with Transparent Fill Type.
Using the zoom draw a left hand with fingers upwards. [3]
Save it as handL0k.xcf (hand Left 0°
Black).
Open the Layer Dialog. Double click on the layer to open the
Layer Attributes Dialog and rename it to handL0k.
Duplicate the layer. Let visible only the duplicated layer,
select it and apply a 90° rotation (Layer/Transform/ 90°
rotation clockwise). Rename it to handL90k.
Repeat the same operations to create handL180k and handL-90k (or
handL270k).
Creating images of dimension 2 (y)
This dimension in our example has two ranks, one for left hand
and the other for right hand. The left hand rank exists yet. We
shall build right hand images by flipping it horizontally.
Duplicate the handL0k layer. Let it visible only and select it.
Rename it to handR0K. Apply Layer/Transform/Flip Horizontally.
Repeat the same operation on the other left hand layers to
create their right hand equivalent.
Re-order layers to have a clockwise rotation from top to
bottom, alternating Left and Right: handL0k, handR0k, handL90k,
handR90k, ..., handR-90k.
Creating images of dimension 3 (z) Creating images of dimension 3 (z) :
The third dimension has two ranks, one for black color and the
other for blue color. The first rank, black, exists yet. We well
see that images of dimension 3 will be a copy, in blue, of the
images of dimension 2. So we will have our 16 images. But a row
of 16 layers is not easy to manage: we will use layers with two
images.
Select the handL0k layer and let it visible only. Using
Image/Canvas Size change canvas size to 60x30 pixels.
Duplicate hand0k layer. On the copy, fill the hand with blue
using Bucket Fill tool.
Now, select the Move tool. Double click on it to accede to its
properties: check Move the Current Layer
option. Move the blue hand into the right part of the layer
precisely with the help of Zoom .
Make sure only handL0k and its blue copy are visible. Right
click on the Layer Dialog: Apply the Merge Visible
Layers command with the option Expand as
Necessary . You get a 60x30 pixels layer with the
black hand on the left and the blue hand on the right. Rename it
to “ handsL0 ” .
Repeat the same operations on the other layers.
Set layers in order
Layers must be set in
order so that GIMP can find the required image at some point
of using the brush. Our layers are yet in order but we must
understand more generally how to have them in order.There are
two ways to imagine this setting in order. The first method is
mathematical: GIMP divides the 16 layers first by 4; that gives
4 groups of 4 layers for the first dimension. Each group
represents a direction of the brush. Then, it divides each group
by 2; that gives 8 groups of 2 layers for the second dimension:
each group represents a L/R alternation. Then another division
by 2 for the third dimension to represent a color at random
between black and blue.
The other method is visual, by using the array representation.
Correlation between two methods is represented in next image:
How will GIMP read this array? : GIMP
starts with the first dimension which is programmed for
“ angular ” , for instance 90°. In this 90°
rank, in yellow, in the second dimension, it selects a L/R
alternation, in an “ incremental ” way. Then,
in the third dimension, in a random way, it chooses a color.
Finally, our layers must be in the following order:
Voilà. Your brush is ready. Save it as
.xcf first, then as
.gih with the following
parameters:
Spacing: 100 Description: Hands Cell Size: 30x30 Number of cells: 16 Dimensions: 3 Dimension 1: 4 ranks Selection: Angular Dimension 2: 2 ranks Selection: Incremental Dimension 3: 2 ranks Selection: Random
Place your .gih file into
GIMP brush directory and refresh the brush
box. You can now use your brush.
Figure 7.19.
Here is the result by stroking an elliptical selection
with the brush:
This brush alternates right hand and left hand regularly,
black and blue color at random, direction according to
four brush directions.
[2]
For previous GIMP versions you may have
to replace “ clockwise ” with
“ counter-clockwise ” .
[3]
Ok, we are cheating here: our hand is borrowed from http://commons.wikimedia.org/wiki/File:Stop_hand.png .
7. Adding New Brushes 9. Varying brush size
 Report an error in Bugzilla  7. Adding New Brushes 7. Adding New Brushes Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. Adding New Brushes
To add a new brush, after either creating or downloading it, you need to
save it in a format GIMP can use . The brush file needs to be placed in the
GIMP's brush search path , so that GIMP is able to index and display it in
the Brushes dialog. You can hit the Refresh
button, which reindexes the brush directory. GIMP uses three file formats
for brushes:
GBR
The .gbr (" g imp
br ush") format is used for ordinary and
color brushes. You can convert many other types of images,
including many brushes used by other programs, into GIMP
brushes by opening them in GIMP and saving them with file
names ending in .gbr . This brings up a
dialog box in which you can set the default Spacing for the
brush. A more complete description of the GBR file format
can be found in the file gbr. txt in the
devel-docs directory of
the GIMP source distribution.
Figure 7.17.
Save a .gbr brush
GIH
The .gih (" g imp
i mage h ose") format
is used for animated brushes. These brushes are constructed
from images containing multiple layers: each layer may
contain multiple brush-shapes, arranged in a grid. When you
save an image as a .gih file, a dialog
comes up that allows you to describe the format of the brush.
Look at The GIH dialog
box for more information about the dialog. The GIH
format is rather complicated: a complete description can be
found in the file gih. txt in the
devel-docs directory of the GIMP source
distribution.
VBR
The .vbr format is used for parametric
brushes, i. e., brushes created using the Brush Editor .
There is really no other meaningful way of obtaining files
in this format.
To make a brush available, place it in one of the folders in GIMP's brush
search path . By default, the brush search path includes two folders , the
system brushes folder, which you should not use or
alter, and the brushes folder inside your personal
GIMP directory . You can add new folders to the brush search path using the
Brush Folders
page of the Preferences dialog. Any GBR, GIH, or VBR file included in a
folder in the brush search path will show up in the Brushes dialog the
next time you start GIMP , or as soon as you press the
Refresh button in the Brushes dialog.
Note
When you create a new parametric brush using the Brush Editor, it
is automatically saved in your personal
brushes folder.
There are a number of web sites with downloadable collections of GIMP
brushes. Rather than supplying a list of links that will soon be out of
date, the best advice is to do a search with your favorite search engine
for “ GIMP brushes ” .
There are also many collections of brushes for other programs with
painting functionality. Some can be converted easily into GIMP brushes,
some require special conversion utilities, and some cannot be converted at
all. Most fancy procedural brush types fall into the last category. If you
need to know, look around on the web, and if you don't find anything, look
for an expert to ask.
6. Brushes 8. The GIH Dialog Box  Report an error in Bugzilla  3. 6. Drag and Drop 3.6. Drag and Drop 3. Opening Files  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 6. Drag and Drop
Drag and drop a file onto the GIMP Toolbox
to open the file. Drag an image into an open
GIMP image to add dropped file as a new
layer, or set of layers, to the already open image.
Many applications support dragging and dropping an image into
GIMP ; for example, drag an image from
Firefox and drop it onto
GIMP 's toolbox.
3.5. File Manager 3.7. Copy and Paste  Report an error in Bugzilla  3. 4. Using External Programs 3.4. Using External Programs 3. Opening Files  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 4. Using External Programs GIMP uses plugins for reading and writing all
file formats except XCF. These plugins may use external libraries or
programs. For example, GIMP does not directly support
PostScript . Instead,
for reading (or writing) PostScript files (file extension
.ps or
.eps ), GIMP
requires a powerful free software program called
Ghostscript .
Installing Ghostscript
Linux distributions almost always come with Ghostscript already
installed (not necessarily the most recent version). For other
operating systems, you may have to install it yourself. Here are
instructions for installing it on Windows:
Go to the Ghostscript project page on Sourceforge
[ GHOSTSCRIPT ] .
Look for the package gnu-gs or
ghostscript (for non-commercial
use only) and go to the download section.
Download one of the prepared Windows distributions, such as
gs650w32.exe or
gs700w32.exe .
Start the executable and follow the instructions for the
installation procedure.
Set the GS_PROG environment variable to the full
file name of the gswin32c binary (e.g.
C:\gs\gsX.YY\bin\gswin32c.exe ).
Now you should be able to read PostScript files with
GIMP . Please note that you must not move the
Ghostscript directories once the installation is complete. The
installation creates registry entries which allow Ghostscript to find
its libraries. (These instructions courtesy of
http://www.kirchgessner.net.)
3.3. Open Recent 3.5. File Manager
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3. 5. File Manager 3.5. File Manager 3. Opening Files  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 5. File Manager
If you have associated an image file type with
GIMP ,
either when you installed GIMP or later, then you
can navigate to the file using a file manager (such as Nautilus or
Konqueror in Linux, or Windows Explorer in Windows), and once you
have found it, double-click on the file. If properly configured,
the image will open in GIMP .
3.4. Using External Programs 3. 6. Drag and Drop  Report an error in Bugzilla 
2. Creating new Files 2. Creating new Files Chapter 5. Getting Images into GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Creating new Files Use
File → New
to open the Create a new image dialog .
Modify the initial width and height of the file or
use the standard values, then create a new image file.
More information about the Create a new image dialog can be found in Section 2 .2, “New” .
Chapter 5. Getting Images into GIMP 3. Opening Files
 Report an error in Bugzilla  3. Opening Files 3. Opening Files Chapter 5. Getting Images into GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Opening Files
There are several ways of opening an existing image in
GIMP :
3.1. Open File
The most obvious way to open an existing image is the menu.
Use
File → Open
to open the Open Image dialog,allowing you
to navigate to the file and click on its name. This method works well
if you know the name and location of the file you want to open.
Although the Open Image dialog does have a
preview pane, it is not convenient (easy) to find an image based on
a thumbnail.
Note
While opening a file, GIMP must determine the file
type. Unfortunately, the file extension, such as
.jpg , is not
reliable: file extensions vary from system to
system; any file can be renamed to have any extension; and there are
many reasons why a file name might lack an extension.
GIMP
first tries to recognize a file by examining its contents: most of the
commonly used file formats have “ magic headers ” that permit
them to be recognized. Only if the magic yields no result does
GIMP resort to using the extension.
Figure 5.4. The “ Open Image ” dialog GIMP
2.2 introduced a new Open Image dialog that
provides several features to help
you navigate quickly to a file. Perhaps the most
important is the ability to create “ bookmarks ” , or
Places ,
for folders that you use often. Your list of bookmarks appears on the
left side of the dialog. The ones at the top, such as
“ Desktop ” , are provided automatically. Use the
the Add button to add the current directory to
the list. Use the Remove button to remove the
selected bookmark. Double-click on a bookmark to navigate directly
to that directory.
The center of the dialog contains a listing of the contents of the
selected directory. Subdirectories are shown at the top of the list ,
files below them. By default, all files in the directory are listed, but
you can restrict the listing to image files of a specific type using the
File Type selection menu that appears beneath the directory listing.
When you select an image file entry in the listing, a
preview appears on the right side of the dialog, along with some
basic information about the image. Note that previews
are cached when they are generated, and there are some things you can do
that may cause a preview to be incorrect. If you suspect that this may
be happening, you can force a new preview to be generated by holding
down the Ctrl key and clicking in the Preview area.
By default, a Location text box is present in the
File Open dialog . It may be absent: the
Ctrl + L key
combination toggles this text box. Alternatively, you can click on
the icon of the paper and pencil in the upper left corner to toggle the
text box.
Note
If you select a file name from the
list, and click the “ Open ” button in the lower right
corner or the dialog, it is almost always true that
GIMP will automatically
determine the file type for you. On rare occasions, mainly if the
file type is unusual and the name lacks a meaningful extension,
GIMP may fail to correctly identify the file
type. Use Select File Type at the bottom
of the dialog to manually specify the file type if this is required.
More commonly, though, if GIMP fails to open an
image file, it is either corrupt or not a supported format.
2. Creating new Files 3.2. Open Location
 Report an error in Bugzilla  3. 2. Adding Fonts 3.2. Adding Fonts 3. Text  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Adding Fonts
For the most authoritative and up-to-date information on fonts
in GIMP, consult the “ Fonts in GIMP 2.0 ” page
[ GIMP-FONTS ]
at the GIMP web site. This section attempts to give you a
helpful overview.
GIMP uses the FreeType 2 font engine to render fonts, and a system
called Fontconfig to manage them. GIMP will let you use any font in
Fontconfig's font path; it will also let you use any font it finds in
GIMP's font search path, which is set on the
Font Folders
page of the Preferences dialog. By default, the font search path
includes a system GIMP-fonts folder (which you should not alter, even
though it is actually empty), and a fonts
folder inside your personal GIMP directory . You can add new folders to
the font search path if it is more convenient for you.
FreeType 2 is a very powerful and flexible system. By default, it
supports the following font file formats:
TrueType fonts (and collections) Type 1 fonts CID-keyed Type 1 fonts CFF fonts OpenType fonts (both TrueType and CFF variants) SFNT-based bitmap fonts X11 PCF fonts Windows FNT fonts BDF fonts (including anti-aliased ones) PFR fonts Type42 fonts (limited support)
You can also add modules to support other types of font files. See
FREETYPE 2 [ FREETYPE ] for more
information.
Linux.
On a Linux system, if the Fontconfig utility is set up as usual, all
you need to do to add a new font is to place the file in the directory
~/.fonts .
This will make the font available not only to GIMP, but to any other
program that uses Fontconfig. If for some reason you want the font to
be available to GIMP only, you can place it in the
fonts
sub-directory of your personal GIMP directory, or some other location
in your font search path. Doing either will cause the font to show up
the next time you start GIMP . If you want to use it in an already
running GIMP, press the Refresh
button in the Fonts dialog .
Windows.
The easiest way to install a font is to drag the file onto the
Fonts directory and let the shell do its magic. Unless you've done
something creative, it's probably in its default location of
C:\windows\fonts
or
C:\winnt\fonts .
Sometimes double-clicking on
a font will install it as well as display it; sometimes it only
displays it. This method will make the font available not only to
GIMP , but also to other Windows applications.
Mac OS X.
There are several ways to install fonts on your system. You can
drag-and-drop them to the “ Fonts ” folder in
“ Libraries ” folder of your “ Home Folder ” . Or
you may use Font Book , invoked by
double-clicking the font file icon in the Finder. You can see what the
font looks like, and click your favorite fonts so that their files are
to be installed on the system. These methods will make the fonts
available for all applications, not only GIMP . If
you want all users can use the fonts, drag-and-drop the fonts to the
“ Fonts ” folder in “ Libraries ” folder of the
Mac OS X ™ Disk, or to the
“ Computer ” folder in the Collection
column of Font Book .
To install a Type 1 file, you need both the
.pfb and .pfm
files. Drag the one that gets an icon into the fonts folder.
The other one doesn't strictly need to be in the same directory
when you drag the file, since it uses some kind of search
algorithm to find it if it's not, but in any case putting it in
the same directory does no harm.
In principle, GIMP can use any type of font on Windows that FreeType can
handle; however, for fonts that Windows can't handle natively, you
should install them by placing the font files in the
fonts
folder of your personal GIMP directory , or some other location in your
font search path. The support Windows has varies by version. All that
GIMP runs on support at least TrueType, Windows FON, and Windows FNT.
Windows 2000 and later support Type 1 and OpenType. Windows ME supports
OpenType and possibly Type 1 (but the most widely used Windows GIMP
installer does not officially support Windows ME, although it may work
anyway).
Note
GIMP uses Fontconfig to manage fonts on Windows as well as Linux. The
instructions above work because Fontconfig by default uses the Windows
fonts directory, i. e., the same fonts that Windows uses itself. If
for some reason your Fontconfig is set up differently, you will have
to figure out where to put fonts so that GIMP can find them: in any
case, the fonts
folder of your personal GIMP directory should work.
3. Text 3.3. Font Problems
 Report an error in Bugzilla 
3. Rendering a Grid 3. Rendering a Grid Chapter 12. Enrich my GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Rendering a Grid
How can you create a grid that is actually part of the image? You can't do
this using the image grid: that is only an aid, and is only visible on the
monitor or in a screenshot. You can, however, use the
Grid
plugin to render a grid very similar to the image grid. (Actually, the
plugin has substantially more options.)
See also Grid and Guides .
2.2. Guides 4. How to Set Your Tile Cache  Report an error in Bugzilla 
3.8. Image Browser 3.8. Image Browser 3. Opening Files  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 8. Image Browser
Linux supports an image-management application named
gThumb . Besides being an excellent
image browser, you can right click an image, choose
Open with , then select
GIMP from the list of options. You can also
drag an image from gThumb onto the
GIMP toolbox.
See the gThumb home page [ GTHUMB ]
for more information. Other similar applications are : GQview
[ GQVIEW ] , and XnView
[ XNVIEW ] .
3.7. Copy and Paste Chapter 6. Getting Images out of GIMP  Report an error in Bugzilla  3. Creating New Layers 3. Creating New Layers Chapter 8. Combining Images  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Creating New Layers There are several ways to create new layers in an image. Here are the most
important ones:
Selecting
Layer → New Layer
in the image menu. This brings up a dialog that allows you
to set the basic properties of the new layer; see the
New Layer dialog
section for help with it.
Selecting
Layer → Duplicate Layer
in the image menu. This creates a new layer , that is a perfect
copy of the currently active layer , just above the active layer .
When you “ cut ” or “ copy ” something, and
then paste it using
Ctrl + V or
Edit → Paste ,
the result is a “ floating selection ” ,
which is a sort of temporary layer.
Before you can do anything else, you either have to anchor
the floating selection to an existing layer, or convert it
into a normal layer. If you do the latter, the new layer
will be sized just large enough to contain the pasted
material.
2. Layer Modes 4. Layer Groups
 Report an error in Bugzilla 
3. 7. Copy and Paste 3.7. Copy and Paste 3. Opening Files  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 7. Copy and Paste
Use
File → Create → From Clipboard to create a new image from the clipboard; alternatively, you can use
Edit → Past as → New image .
Many applications support copying an image to the clipboard that can
then be pasted into GIMP . Many operating systems
support copying screens to the clipboard.
Print Screen typically copies the screen to the
clipboard, and
ALT + Print Screen
copies only the active window. Print screen is not universally
supported, and just because your operating system can copy an image to
the clipboard , does not mean that GIMP can use
the image from the clipboard. Your best bet is to try it and see
if it works.
3.6. Drag and Drop 3.8. Image Browser
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3. 2. Open Location 3. 2. Open Location 3. Opening Files  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Open Location
If instead of a file name, you have a URI
(i.e., a web address) for the image, you can open it using the
menu, by choosing
File → Open Location…
from an image menu. This brings up a small dialog that allows you to
enter (or paste) the URI .
Figure 5.5. The “ Open Location ” dialog The “ Open Location ” dialog .
3. Opening Files 3.3. Open Recent
 Report an error in Bugzilla  3. 3. Open Recent 3.3. Open Recent 3. Opening Files  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 3. Open Recent
The easiest way to open an image that was recently open in
GIMP , may be using
File → Open Recent .
This displays a scrollable list of the mostly recently opened
images with icons beside them.
Select and open the desired image.
3.2. Open Location 3. 4. Using External Programs  Report an error in Bugzilla 
5. 3. Paths and Selections 5.3. Paths and Selections 5.
Paths
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 3. Paths and Selections
GIMP lets you transform the selection for an image into a path; it also
lets you transform paths into selections. For information about the
selection and how it works, see the
Selection section.
When you transform a selection into a path , the path closely follows the
“ marching ants ” .
Now, the selection is a two-dimensional entity, but a path is a
one-dimensional entity, so there is no way to transform the selection
into a path without losing information. In fact, any information about
partially selected areas (i.e., feathering) are lost when a
selection is turned into a path. If the path is transformed back into a
selection, the result is an all-or-none selection, similar to what is
obtained by executing "Sharpen" from the Select menu.
5.2. Path Properties 5. 4. Transforming Paths
 Report an error in Bugzilla 
5. 7. Paths and SVG files 5.7. Paths and SVG files 5.
Paths
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 7. Paths and SVG files SVG , standing for “ Scalable Vector
Graphics ” , is an increasingly popular file format for
vector graphics , in which graphical elements are
represented in a resolution-independent format, in contrast to
raster graphics ; in which graphical elements are
represented as arrays of pixels. GIMP is mainly a raster graphics
program, but paths are vector entities.
Fortunately, paths are represented in SVG files in
almost exactly the same way they are represented in GIMP. (Actually
fortune has nothing to do with it: GIMP's path handling was rewritten
for GIMP 2.0 with SVG paths in mind.) This compatibility makes it
possible to store GIMP paths as SVG files without
losing any information. You can access this capability in the Paths
dialog.
It also means that GIMP can create paths from
SVG files saved in other programs, such as
Inkscape or
Sodipodi ,
two popular open-source vector graphics applications. This is nice
because those programs have much more powerful path-manipulation tools
than GIMP does. You can import a path from an SVG
file using the Paths dialog.
The SVG
format handles many other graphical elements than just paths: among
other things, it handles figures such as squares, rectangles, circles,
ellipses, regular polygons, etc. GIMP cannot do anything with these
entities, but it can load them as paths.
Note
Creating paths is not the only thing GIMP can do with
SVG files. It can also open
SVG files as GIMP images, in the usual way.
5.6. Paths and Text 6. Brushes
 Report an error in Bugzilla 
5. 6. Paths and Text 5.6. Paths and Text 5.
Paths
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 6. Paths and Text Figure 7.14. Text converted to a path Text converted to a path and then transformed using the
Perspective tool.
The path shown above, stroked with a fuzzy brush and then
gradient-mapped using the Gradient Map filter with the
“ Yellow Contrast ” gradient.
A text item created using the Text tool can be transformed into a path
using the Path from Text command in the
the context menu of the Text tool. This can be useful for several
purposes, including:
Stroking the path, which gives you many possibilities for fancy
text.
More importantly, transforming the text. Converting text into a
path, then transforming the path, and finally either stroking the
path or converting it to a selection and filling it, often leads to
much higher-quality results than rendering the text as a layer and
transforming the pixel data.
5.5. Stroking a Path 5. 7. Paths and SVG files  Report an error in Bugzilla 
5. 2. Path Properties 5. 2. Path Properties 5.
Paths
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 2. Path Properties
Paths, like layers and channels, are components of an image. When an
image is saved in GIMP 's native XCF file format, any
paths it has are saved with it. The list of paths in an image can be
viewed and operated on using the
Paths dialog .
You can move a path from one image to another by copying and pasting
using the pop-up menu in the Paths dialog, or by dragging an icon from
the Paths dialog into the destination image window.
GIMP paths belong to a mathematical type called
“ Bezier paths ” . What this means in practical terms is that
they are defined by anchors and
handles . “ Anchors ” are points the path
goes through. “ Handles ” define the direction of a path when
it enters or leaves an anchor point: each anchor point has two handles
attached to it.
Paths can be very complex. If you create them by hand using the Path
tool, unless you are obsessive they probably won't contain more than a
few dozen anchor points (often many fewer); but if you create them by
transforming a selection into a path , or by transforming text into a
path, the result can easily contain hundreds of anchor points, or even
thousands.
A path may contain multiple components . A
“ component ”
is a part of a path whose anchor points are all connected to each other
by path segments. The ability to have multiple components in paths
allows you to convert them into selections having multiple disconnected
parts.
Each component of a path can be either open or
closed : “ closed ”
means that the last anchor point is connected to the first anchor point.
If you transform a path into a selection, any open components are
automatically converted into closed components by connecting the last
anchor point to the first anchor point with a straight line.
Path segments can be either straight or curved. A path is called
“ polygonal ” if all of its segments are straight.
A new path segment is always created straight; the handles for the
anchor points are directly on top of the anchor points, yielding
handles of zero length, which produces straight-line segments.
Drag a handle handle away from an anchor point to cause a segment
to curve.
One nice thing about paths is that they use very few resources,
especially in comparison with images. Representing
a path in RAM requires storing only the coordinates of its anchors and
handles: 1K of memory is enough to hold a complex path, but not
enough to hold a small 20x20 pixel RGB layer. Therefore, it is
possible to have literally hundreds of paths in an image without causing
any significant stress to your system; the amount of stress that
hundreds of paths might cause you , however,
is another question. Even a path with thousands of segments
consumes minimal resources in comparison to a typical layer or channel.
Paths can be created and manipulated using the
Path tool .
5.
Paths
5.3. Paths and Selections
 Report an error in Bugzilla  5. 5. Stroking a Path 5. 5. Stroking a Path 5.
Paths
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 5. Stroking a Path Figure 7.12. Stroking paths
The four paths from the top illustration, each stroked in a
different way.
Paths do not alter the appearance of the image pixel data unless
they are stroked , using
Edit → Stroke Path
from the image menu or the Paths dialog right-click menu, or the
“ Stroke Path ” button in the Tool Options dialog for the
Path tool.
Choosing “ Stroke Path ” by any of these means brings up a
dialog that allows you to control the way the stroking is done. You
can choose from a wide variety of line styles , or you can stroke with
any of the Paint tools, including unusual ones such as the Clone tool,
Smudge tool, Eraser, etc.
Figure 7.13. The Stroke Path dialog
You can further increase the range of stroking effects by stroking a
path multiple times, or by using lines or brushes of different widths.
The possibilities for getting interesting effects in this way are almost
unlimited.
5.4. Transforming Paths 5. 6. Paths and Text  Report an error in Bugzilla 
5. 4. Transforming Paths 5. 4. Transforming Paths 5.
Paths
 Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 4. Transforming Paths
Each of the Transform tools (Rotate, Scale, Perspective, etc) can be set
to act on a layer, selection, or path. Select the transform tool in the
toolbox, then select layer, selection, or path for the
“ Transform: ” option in the tool's Tool Options
dialog. This gives you a powerful set of
methods for altering the shapes of paths without affecting other
elements of the image.
By default a Transform tool, when it is set to affect paths, acts on
only one path: the active path
for the image , which is shown highlighted in the Paths dialog. You can
make a transformation affect more than one path, and possibly other
things as well, using the “ transform lock ” buttons in the
Paths dialog.
Not only paths, but also layers and channels, can be transform-locked.
If you transform one element that is transform-locked, all others will
be transformed in the same way. So, for example, if you want to scale a
layer and a path by the same amount, click the transform-lock buttons
so that “ chain ” symbols appear next to the layer in the
Layers dialog, and the path in the Paths dialog; then use the Scale
tool on either the layer or the path, and the other will automatically
follow.
5.3. Paths and Selections 5.5. Stroking a Path  Report an error in Bugzilla  5. Paths 5.
Paths
Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5.
Paths
Paths are curves (known as Bézier-curves). Paths are easy to learn and use
in GIMP . To understand their concepts and
mechanism, look at the glossary
Bézier-curve or Wikipedia
[ WKPD-BEZIER ] .
The Paths tool is very powerful, allowing you to design sophisticated
forms. To use the Paths tool in GIMP , you must first
create a path, and then stroke the path.
In GIMP , the term “ Stroke path ” means to
apply a specific style to the path (color, width, pattern... ).
A Path has two main purposes:
You can convert a closed path to a selection.
Any path, open or closed, can be stroked ;
that is, painted on the image in a variety of ways .
Figure 7.10. Illustration of four different path creating
Four examples of GIMP paths: one closed and polygonal; one open and
polygonal; one closed and curved; one with a mixture of straight and
curved segments.
5.1. Path Creation
Start by drawing the outline for your path; the outline
can be modified later (see the
Paths tool).
To start, select the Paths tool using one of the following methods:
Use
Tools → Path
from the image menu .
Use the relevant icon
in toolbox.
Use the hotkey B .
When the Paths tool is selected, the mouse cursor
changes into a pointer (arrow) with a curve.
Left click in the image to create the first point on the path. Move
the mouse to a new point and left click the mouse to create another
point linked to the previous point. Although you can create as many
points as you desire, you only need two points to learn about Paths.
While adding points, the mouse cursor has a little “ + ”
next to the curve, which indicates that clicking will add a new
point. When the mouse cursor is close to a line segment, the
“ + ” changes into a cross with arrows; like the move tool.
Move the mouse cursor close to a line segment, left-click and drag
the line segment. Two events occur.
The line segment bends and curves as it is pulled.
Each line segment has a start point and an end point that is
clearly labeled. A “ direction line ” now
projects from each end point for the line segment that was
moved.
The curved line segment leaves an end point in the same direction that
the “ direction line ” leaves the end point. The length of
the “ direction line ” controls how far the line segment
projects along the “ direction line ” before curving toward
the other end point. Each “ direction line ” has an empty
square box (called a handle) on one end. Click and drag a handle to
change the direction and length of a “ direction line ” .
Figure 7.11. Appearance of a path while it is manipulated Appearance of a path while it is manipulated using the Path tool .
The path is comprised of two components with both straight and curved
segments. Black squares are anchor points, the open circle indicates
the selected anchor, and the two open squares are the handles associated
with the selected anchor.
4. Using QuickMask Mode 5.2. Path Properties
 Report an error in Bugzilla  4. Using QuickMask Mode 4. Using QuickMask Mode Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. Using QuickMask Mode Open an image or begin a new document.
Activate QuickMask mode using the left-bottom button in the image
window . If a selection is present the mask is initialized with the
content of the selection.
Choose any drawing tool. Paint on the QuickMask with black to
remove selected areas, and paint with white to add selected
areas. Use grey colors to partially select areas.
You can also use selection tools and fill these selections with the
Bucket Fill tool ; this does not destroy the QuickMask selections!
Toggle QuickMask mode off using the left-bottom button in the image
window : the selection will be displayed with marching ants.
3.2. Properties 5.
Paths
 Report an error in Bugzilla  14.2. Creating a Basic Shape 14.2. Creating a Basic Shape 14. Drawing Simple Objects  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  14.2. Creating a Basic Shape GIMP is not designed to be used for
drawing. [4]
However, you may create shapes by either painting them using the
technique described in Section 14.1, “Drawing a Straight Line” or by using
the selection tools. Of course, there are various other ways to
paint a shape, but we'll stick to the easiest ones here. So, create
a new image and check that the
foreground and background
colors are different.
Figure 7. 39. Creating a rectangular selection
The screenshot shows how a rectangular selection is created.
Press and hold the left mouse button while you move the mouse
in the direction of the red arrow.
Basic shapes like rectangles or ellipses, can be
created using the
selection tools . This
tutorial uses a rectangular selection as an example. So,
choose the rectangular
selection tool and create a new selection: press and
hold the left mouse button while you move the mouse to another
position in the image (illustrated in figure
Figure 7.39, “Creating a rectangular selection” ). The selection is created
when you release the mouse button . For more
information about key modifiers see
selection tools .
Figure 7.40. Rectangular selection filled with foreground color
The screenshot shows a rectangular selection filled with the
foreground color .
After creating the selection, you can either create a filled
or an outlined shape with the foreground color of your choice.
If you go for the first option, choose a
foreground color
and fill the selection with the
bucket fill tool .
If you choose the latter option, create an outline by using
the Stroke
selection menu item from the Edit
menu. If you're satisfied with the result,
remove the selection .
[4]
Try out e.g. [ INKSCAPE ] for
this purpose.
14. Drawing Simple Objects Chapter 8. Combining Images
 Report an error in Bugzilla  3. 6. Extending The Text Box Script 3.6. Extending The Text Box Script 3. A Script-Fu Tutorial  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 6. Extending The Text Box Script 3.6. 1. Handling Undo Correctly
When creating a script, you want to give your users the ability to
undo their actions, should they make a mistake. This is easily
accomplished by calling the functions
gimp-undo-push-group-start
and gimp-undo-push-group-end
around the code that manipulates the image. You can think of them as
matched statements that let GIMP know when to start
and stop recording manipulations on the image, so that those
manipulations can later be undone.
If you are creating a new image entirely, it doesn't make sense to use
these functions because you're not changing an existing image.
However, when you are changing an existing image, you most surely want
to use these functions.
Undoing a script works nearly flawlessly when using these functions.
3.6.2. Extending The Script A Little More
Now that we have a very handy-dandy script to create text
boxes, let's add two features to it:
Currently, the image is resized to fit exactly around the
text — there's no room for anything, like drop shadows or
special effects (even though many scripts will automatically
resize the image as necessary). Let's add a buffer around
the text, and even let the user specify how much buffer to
add as a percentage of the size of the resultant text.
This script could easily be used in other scripts that work
with text. Let's extend it so that it returns the image and
the layers, so other scripts can call this script and use
the image and layers we create.
3.6.3.
Modifying The Parameters And The Registration Function
To let the user specify the amount of buffer, we'll add a parameter to
our function and the registration function:
( define (script-fu-text-box inTest inFont inFontSize inTextColor inBufferAmount)
( let*
(
; define our local variables
; create a new image:
(theImageWidth 10)
(theImageHeight 10)
(theImage (car
(gimp-image-new
theImageWidth
theImageHeight
RGB
)
)
)
(theText) ;a declaration for the text
;we create later
(theBuffer) ; added
( theLayer
(car
(gimp-layer-new
theImage
theImageWidth
theImageHeight
RGB-IMAGE
"layer 1"
100
NORMAL
)
)
)
) ;end of our local variables
[Code here]
)
( script-fu-register
"script-fu-text-box" ;func name
"Text Box" ;menu label
"Creates a simple text box, sized to fit\
around the user's choice of text,\
font, font size, and color." ;description
"Michael Terry" ;author
"copyright 1997, Michael Terry;\
2009, the GIMP Documentation Team" ;copyright notice
"October 27, 1997" ;date created
"" ;image type that the script works on
SF-STRING "Text" "Text Box" ;a string variable
SF-FONT "Font" "Charter" ;a font variable
SF-ADJUSTMENT "Font size" '(50 1 1000 1 10 0 1)
;a spin-button
SF-COLOR "Color" '(0 0 0) ;color variable
SF-ADJUSTMENT "Buffer amount" '(35 0 100 1 10 1 0)
;a slider
)
( script-fu-menu-register "script-fu-text-box" " & lt;Image & gt;/ Font/Create/Text")
3.6.4. Adding The New Code
We're going to add code in two places: right before we resize
the image, and at the end of the script (to return the new
image, the layer and the text ).
After we get the text's height and width, we need to resize
these values based on the buffer amount specified by the
user. We won't do any error checking to make sure it's in the
range of 0-100% because it's not life-threatening, and because
there's no reason why the user can't enter a value like
“ 200 ” as the percent of buffer to add.
( set! theBuffer (* theImageHeight (/ inBufferAmount 100) ) )
(set! theImageHeight (+ theImageHeight theBuffer theBuffer) )
(set! theImageWidth (+ theImageWidth theBuffer theBuffer) )
All we're doing here is setting the buffer based on the height of the
text, and adding it twice to both the height and width of our new
image. (We add it twice to both dimensions because the buffer needs to
be added to both sides of the text.)
Now that we have resized the image to allow for a buffer , we
need to center the text within the image. This is done by
moving it to the (x, y) coordinates of ( theBuffer ,
theBuffer ). I added this line after
resizing the layer and the image :
( gimp-layer-set-offsets theText theBuffer theBuffer)
Go ahead and save your script, and try it out after refreshing the
database.
All that is left to do is return our image, the layer, and the text
layer. After displaying the image, we add this line:
(list theImage theLayer theText)
This is the last line of the function, making this list available to
other scripts that want to use it.
To use our new text box script in another script, we could write
something like the following:
(set! theResult (script-fu-text-box
"Some text"
"Charter" "30"
'(0 0 0)
"35"
)
)
(gimp-image-flatten (car theResult))
Congratulations, you are on your way to your Black Belt of Script-Fu!
3.5. Giving Our Script Some Guts 3.7. Your script and its working  Report an error in Bugzilla  3. 4. Your First Script-Fu Script 3.4. Your First Script-Fu Script 3. A Script-Fu Tutorial  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 4. Your First Script-Fu Script
Do you not need to stop and catch your breath? No? Well then,
let's proceed with your fourth lesson — your first Script-Fu
Script .
3. 4. 1. Creating A Text Box Script
One of the most common operations I perform in GIMP
is creating a box with some text in it for a web page, a logo or
whatever. However, you never quite know how big to make the
initial image when you start out. You don't know how much
space the text will fill with the font and font size you
want.
The Script-Fu Master (and student) will quickly realize that
this problem can easily be solved and automated with
Script-Fu.
We will, therefore, create a script, called Text Box, which
creates an image correctly sized to fit snugly around a line
of text the user inputs. We'll also let the user choose the
font, font size and text color.
3.4.2. Editing And Storing Your Scripts
Up until now, we've been working in the Script-Fu Console . Now,
however, we're going to switch to editing script text files.
Where you place your scripts is a matter of preference — if you
have access to GIMP 's default script directory, you
can place your scripts
there. However, I prefer keeping my personal scripts in my own script
directory, to keep them separate from the factory-installed scripts.
In the .gimp-2.8 directory that
GIMP made off of your home directory, you should
find a directory called scripts .
GIMP will automatically look in your
.gimp-2.8 directory for a
scripts directory, and add the
scripts in this directory to the
Script-Fu database. You should place your personal scripts here.
3.4.3. The Bare Essentials
Every Script-Fu script defines at least one function, which is the
script's main function. This is where you do the work.
Every script must also register with the procedural database, so you
can access it within GIMP .
We'll define the main function first:
( define (script-fu-text-box inText inFont inFontSize inTextColor ))
Here, we've defined a new function called
script-fu-text-box that
takes four parameters, which will later correspond to some text, a
font, the font size, and the text's color. The function is currently
empty and thus does nothing. So far, so good — nothing new,
nothing fancy.
3.4.4. Naming Conventions
Scheme's naming conventions seem to prefer lowercase letters with
hyphens, which I've followed in the naming of the function. However,
I've departed from the convention with the parameters. I like more
descriptive names for my parameters and variables, and thus add the
"in" prefix to the parameters so I can quickly see that they're values
passed into the script, rather than created within it. I use the
prefix "the" for variables defined within the script.
It's GIMP convention to name your script functions
script-fu-abc ,
because then when they're listed in the procedural database, they'll
all show up under script-fu when you're listing the functions. This
also helps distinguish them from plug-ins.
3.4.5. Registering The Function
Now, let's register the function with GIMP . This is
done by calling the function script-fu-register .
When GIMP reads in a
script, it will execute this function, which registers the
script with the procedural database. You can place this
function call wherever you wish in your script, but I usually
place it at the end, after all my other code.
Here's the listing for registering this function (I will
explain all its parameters in a minute):
( script-fu-register
"script-fu-text-box" ;func name
"Text Box" ;menu label
"Creates a simple text box, sized to fit\
around the user's choice of text,\
font, font size, and color." ;description
"Michael Terry" ;author
"copyright 1997, Michael Terry;\
2009, the GIMP Documentation Team" ;copyright notice
"October 27, 1997" ;date created
"" ;image type that the script works on
SF-STRING "Text" "Text Box" ;a string variable
SF-FONT "Font" "Charter" ;a font variable
SF-ADJUSTMENT "Font size" '(50 1 1000 1 10 0 1)
;a spin-button
SF-COLOR "Color" '(0 0 0) ;color variable
)
( script-fu-menu-register "script-fu-text-box" " & lt;Image & gt;/ File/Create/Text")
If you save these functions in a text file with a
.scm suffix
in your script directory, then choose
Filters → Script-Fu → Refresh Scripts ,
this new script will appear as
File → Create → Text → Text Box .
If you invoke this new script, it won't do anything, of course, but
you can view the prompts you created when registering the script (more
information about what we did is covered next).
Finally, if you invoke the Procedure Browser (
Help → Procedure Browser ),
you'll notice that our script now appears in the database.
3.4.6. Steps For Registering The Script
To register our script with GIMP , we call the
function script-fu-register , fill in the seven
required parameters and add our script's own parameters, along with a
description and default value for each parameter.
The Required Parameters
The name of the function we
defined. This is the function called when our script is invoked
(the entry-point into our script). This is necessary because we may
define additional functions within the same file, and
GIMP needs to
know which of these functions to call. In our example, we only
defined one function, text-box, which we registered.
The location in the menu where
the script will be inserted. The exact location of the script is
specified like a path in Unix, with the root of the path being
image menu as & lt;Image & gt; . [6]
If your script does not operate on an existing image (and thus
creates a new image, like our Text Box script will), you'll want
to insert it in the image window menu , which you can access
through the image menu bar, by right-clicking the image window,
by clicking the menu button icon at the left-top corner of the
image window, or by pressing F10 .
If your script is intended to work on an image being edited,
you'll want to insert it in the image window menu .
The rest of the path points to the menu lists, menus and sub-menus.
Thus, we registered our Text Box script in the
Text menu of the
Create menu of the File
menu. [7]
( File → Create → Text → Text Box ).
If you notice, the Text sub-menu in the File/Create menu wasn't
there when we began — GIMP automatically
creates any menus not already existing.
A description of your
script, to be displayed in the Procedure Browser.
Your name (the author of the script).
Copyright information.
The date the script was
made, or the last revision of the script.
The types of images the script
works on. This may be any of the following: RGB, RGBA, GRAY,
GRAYA, INDEXED, INDEXEDA. Or it may be none
at all — in our case,
we're creating an image, and thus don't need to define the type of
image on which we work.
Figure 13.4. The menu of our script. 3.4.7. Registering The Script's Parameters
Once we have listed the required parameters, we then need to list the
parameters that correspond to the parameters our script needs. When we
list these params, we give hints as to what their types are. This is
for the dialog which pops up when the user selects our script. We also
provide a default value.
This section of the registration process has the following format:
Param Type Description Example SF-IMAGE
If your script operates on an open image, this should be the
first parameter after the required parameters.
GIMP will
pass in a reference to the image in this parameter.
3 SF-DRAWABLE
If your script operates on an open image, this should be the
second parameter after the SF-IMAGE
param. It
refers to the active layer. GIMP will pass
in a reference to the active layer in this parameter.
17 SF-VALUE
Accepts numbers and strings. Note that quotes must be
escaped for default text, so better use
SF-STRING .
42 SF-STRING Accepts strings. "Some text" SF-COLOR
Indicates that a color is requested in this parameter.
'(0 102 255) SF-TOGGLE
A checkbox is displayed, to get a Boolean value.
TRUE or FALSE 3.4.8.
The Script-Fu parameter API [8]
Note
Beside the above parameter types there are more types for the
interactive mode, each of them will create a widget in the control
dialog. You will find a list of these parameters with descriptions and
examples in the test script
plug-ins/script-fu/scripts/test-sphere.scm
shipped with the GIMP source code .
Param Type Description SF-ADJUSTMENT
Creates an adjustment widget in the dialog.
SF-ADJUSTMENT "label" '(value lower upper step_inc page_inc
digits type)
Widget arguments list Element Description "label" Text printed before the widget. value Value print at the start. lower / upper The lower / upper values (range of choice). step_inc Increment/decrement value. page_inc Increment/decrement value using page key. digits Digits after the point (decimal part). type One of: SF-SLIDER or 0, SF-SPINNER or 1 SF-COLOR Creates a color button in the dialog. SF-COLOR "label" '(red green blue) or SF-COLOR "label" "color" Widget arguments list Element Description "label" Text printed before the widget. '(red green blue)
List of three values for the red, green and blue components .
"color" Color name in CSS notatation. SF-FONT
Creates a font-selection widget in the dialog. It returns a
fontname as a string. There are two new gimp-text procedures to
ease the use of this return parameter:
(gimp-text-fontname image drawable x-pos y-pos text border
antialias size unit font)
(gimp-text-get-extents-fontname text size unit font)
where font is the fontname you get. The size specified in the
fontname is silently ignored. It is only used in the
font-selector. So you are asked to set it to a useful value (24
pixels is a good choice).
SF-FONT "label" "fontname" Widget arguments list Element Description "label" Text printed before the widget. "fontname" Name of the default font. SF-BRUSH
It will create a widget in the control dialog. The widget
consists of a preview area (which when pressed will produce a
popup preview ) and a button with the "..." label. The button
will popup a dialog where brushes can be selected and each of
the characteristics of the brush can be modified.
SF-BRUSH "Brush" '(" Circle (03)" 100 44 0)
Here the brush dialog will be popped up with a default brush of
Circle (03) opacity 100 spacing 44 and paint mode of Normal
(value 0).
If this selection was unchanged the value passed to the function
as a parameter would be '(" Circle (03)" 100 44 0) .
SF-PATTERN
It will create a widget in the control dialog. The widget
consists of a preview area (which when pressed will produce a
popup preview ) and a button with the "..." label. The button
will popup a dialog where patterns can be selected.
SF-PATTERN "Pattern" "Maple Leaves"
The value returned when the script is invoked is a string
containing the pattern name. If the above selection was not
altered the string would contain " Maple Leaves".
SF-GRADIENT
It will create a widget in the control dialog. The widget
consists of a button containing a preview of the selected
gradient.
If the button is pressed a gradient selection dialog will popup.
SF- GRADIENT "Gradient" "Deep Sea"
The value returned when the script is invoked is a string
containing the gradient name. If the above selection was not
altered the string would contain " Deep Sea".
SF-PALETTE
It will create a widget in the control dialog. The widget
consists of a button containing the name of the selected
palette.
If the button is pressed a palette selection dialog will popup.
SF- PALETTE "Palette" "Named Colors"
The value returned when the script is invoked is a string
containing the palette name. If the above selection was not
altered the string would contain " Named Colors".
SF-FILENAME
It will create a widget in the control dialog. The widget
consists of a button containing the name of a file .
If the button is pressed a file selection dialog will popup.
SF- FILENAME "label" (string-append ""
gimp-data-directory "/scripts/beavis.jpg")
The value returned when the script is invoked is a string
containing the filename.
SF-DIRNAME
Only useful in interactive mode. Very similar to SF-FILENAME,
but the created widget allows to choose a directory instead of a
file.
SF-DIRNAME "label" "/var/tmp/images"
The value returned when the script is invoked is a string
containing the dirname.
SF-OPTION
It will create a widget in the control dialog. The widget is a
combo-box showing the options that are passed as a list.
The first option is the default choice.
SF-OPTION "label" '("option1" "option2")
The value returned when the script is invoked is the number of
the chosen option, where the option first is counted as 0.
SF-ENUM
It will create a widget in the control dialog. The widget is a
combo-box showing all enum values for the given enum type. This
has to be the name of a registered enum, without the "Gimp"
prefix. The second parameter speficies the default value, using
the enum value's nick.
SF-ENUM "Interpolation" '("InterpolationType" "linear")
The value returned when the script is invoked corresponds to
chosen enum value.
[6]
Before version 2.6, & lt;Toolbox & gt; could be also
used, but now the toolbox menu is removed, so don't use it.
[7]
The original, written by Mike, says put the menu entry in the
Script-Fu menu of the Xtns menu at the
Toolbox, but since version 2.6, the Toolbox menu had been removed
and merged with the image window menubar.
[8]
This section is not part of the original tutorial.
3.3. Lists, Lists And More Lists 3.5. Giving Our Script Some Guts
 Report an error in Bugzilla 
3. 2. Variables And Functions 3.2. Variables And Functions 3. A Script-Fu Tutorial  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Variables And Functions
Now that we know that every Scheme statement is enclosed in parentheses,
and that the function name/operator is listed first, we need to know how
to create and use variables, and how to create and use functions. We'll
start with the variables.
3.2.1. Declaring Variables
Although there are a couple of different methods for declaring
variables, the preferred method is to use the let*
construct. If
you're familiar with other programming languages, this construct is
equivalent to defining a list of local variables and a scope in which
they're active. As an example, to declare two variables, a and b,
initialized to 1 and 2, respectively, you'd write:
( let*
(
(a 1)
(b 2)
)
(+ a b)
)
or, as one line: ( let* ( (a 1) (b 2) ) (+ a b) ) Note
You'll have to put all of this on one line if you're using the
console window. In general, however, you'll want to adopt a similar
practice of indentation to help make your scripts more readable.
We'll talk a bit more about this in the section on White Space.
This declares two local variables, a and b, initializes them, then
prints the sum of the two variables.
3.2.2. What Is A Local Variable?
You'll notice that we wrote the summation (+ a b) within
the parens of the let* expression, not after it.
This is because the let*
statement defines an area in your script in which the declared
variables are usable; if you type the (+ a b)
statement after the (let* …) statement,
you'll get an error, because the declared
variables are only valid within the context of the let*
statement; they are what programmers call local variables.
3.2.3. The General Syntax Of let* The general form of a let* statement is:
(let* ( variables )
expressions )
where variables are declared within parens, e.g.,
(a 2) , and
expressions are any valid Scheme expressions. Remember that the
variables declared here are only valid within the
let* statement — they're local variables.
3.2.4. White Space
Previously, we mentioned the fact that you'll probably want to use
indentation to help clarify and organize your scripts. This is a good
policy to adopt, and is not a problem in Scheme — white space is
ignored by the Scheme interpreter, and can thus be liberally applied
to help clarify and organize the code within a script. However, if
you're working in Script-Fu's Console window, you'll have to enter an
entire expression on one line; that is, everything between the opening
and closing parens of an expression must come on one line in the
Script-Fu Console window.
3.2.5. Assigning A New Value To A Variable
Once you've initialized a variable, you might need to change its value
later on in the script. Use the set! statement to change
the variable's value:
(let* ( (theNum 10) ) (set! theNum (+ theNum theNum)) )
Try to guess what the above statement will do, then go ahead and enter
it in the Script-Fu Console window.
Note
The “ \ ” indicates that there is no line
break. Ignore it (don't type it in your Script-Fu console and don't
hit Enter ), just continue with the next line.
3.2.6. Functions
Now that you've got the hang of variables, let's get to work with some
functions. You declare a function with the following syntax:
(define
(
name
param-list
)
expressions
)
where name is the name assigned to this
function, param-list is a space-delimited
list of parameter names, and expressions
is a series of expressions that the function executes when it's
called. For example:
(define (AddXY inX inY) (+ inX inY) ) AddXY is the function's name and
inX and inY
are the variables. This function takes its two parameters and adds
them together.
If you've programmed in other imperative languages (like C/C++, Java,
Pascal, etc.), you might notice that a couple of things are absent in
this function definition when compared to other programming languages.
First, notice that the parameters don't have any
“ types ” (that is,
we didn't declare them as strings, or integers, etc.). Scheme is a
type-less language. This is handy and allows for quicker script
writing.
Second, notice that we don't need to worry about how to
“ return ” the result of our function — the last
statement is the value “ returned ” when calling this
function. Type the function into the
console, then try something like:
(AddXY (AddXY 5 6) 4) 3. A Script-Fu Tutorial 3. 3. Lists, Lists And More Lists  Report an error in Bugzilla  3. 3. Lists, Lists And More Lists 3.3. Lists, Lists And More Lists 3. A Script-Fu Tutorial  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 3. Lists, Lists And More Lists
We've trained you in variables and functions, and now enter the
murky swamps of Scheme's lists.
3.3.1. Defining A List
Before we talk more about lists, it is necessary that you know
the difference between atomic values and lists.
You've already seen atomic values when we initialized
variables in the previous lesson. An atomic value is a single
value. So, for example, we can assign the variable
“ x ” the
single value of 8 in the following statement:
(let* ( (x 8) ) x)
(We added the expression x at the end to print out
the value assigned to x —normally you won't
need to do this. Notice how let* operates just like a
function: The value of the last statement is the value returned.)
A variable may also refer to a list of values, rather than a
single value. To assign the variable x the
list of values 1, 3, 5, we'd type:
(let* ( (x '(1 3 5))) x)
Try typing both statements into the Script-Fu Console and
notice how it replies. When you type the first statement in,
it simply replies with the result:
8
However, when you type in the other statement, it replies with
the following result:
(1 3 5)
When it replies with the value 8 it is informing you that
x contains the atomic value 8. However,
when it replies with (1 3 5) , it is
then informing you that
x contains not a single value, but a list
of values. Notice that there are no commas in our declaration
or assignment of the list, nor in the printed result.
The syntax to define a list is: '(a b c)
where a , b , and
c are literals. We use the apostrophe
( ' )
to indicate that what follows in the parentheses is a list of
literal values, rather than a function or expression.
An empty list can be defined as such: '() or simply: () Lists can contain atomic values, as well as other lists:
(let*
(
(x
'("GIMP" (1 2 3) ("is" ("great" () ) ) )
)
)
x
)
Notice that after the first apostrophe, you no longer need to use an
apostrophe when defining the inner lists. Go ahead and copy the
statement into the Script-Fu Console and see what it returns.
You should notice that the result returned is not a list of
single, atomic values; rather, it is a list of a literal
("The GIMP") , the list (1 2 3 ) , etc.
3.3.2. How To Think Of Lists
It's useful to think of lists as composed of a “ head ”
and a “ tail ” .
The head is the first element of the list , the tail the rest of the
list . You'll see why this is important when we discuss how to add to
lists and how to access elements in the list.
3.3.3. Creating Lists Through Concatenation (The Cons Function)
One of the more common functions you'll encounter is the cons
function. It takes a value and places it to its second argument, a
list. From the previous section, I suggested that you think of a list
as being composed of an element (the head) and the remainder of the
list (the tail ). This is exactly how cons functions — it adds an
element to the head of a list. Thus, you could create a list as
follows:
(cons 1 '(2 3 4) ) The result is the list (1 2 3 4) . You could also create a list with one element: (cons 1 () )
You can use previously declared variables in place of any literals, as
you would expect.
3.3.4. Defining A List Using The list Function
To define a list composed of literals or previously declared
variables, use the list function:
( list 5 4 3 a b c)
This will compose and return a list containing the values held
by the variables a , b
and c . For example:
( let* (
(a 1)
(b 2)
(c 3)
)
( list 5 4 3 a b c)
)
This code creates the list (5 4 3 1 2 3) .
3.3.5. Accessing Values In A List
To access the values in a list, use the functions
car and cdr ,
which return the first element of the list and the rest of the list ,
respectively. These functions break the list down into the head::tail
construct I mentioned earlier.
3.3.6. The car Function car returns the first element of the list ( the
head of the list ). The list needs to be non-null. Thus, the
following returns the first element of the list :
(car '("first" 2 "third")) which is: "first" 3.3.7. The cdr function cdr returns the rest of the list after the first
element
(the tail of the list). If there is only one element in the list, it
returns an empty list.
(cdr '("first" 2 "third")) returns: (2 "third") whereas the following: (cdr '("one and only")) returns: () 3.3.8. Accessing Other Elements In A List
OK, great, we can get the first element in a list, as well as
the rest of the list , but how do we access the second, third
or other elements of a list? There exist several "convenience"
functions to access, for example, the head of the head of the
tail of a list ( caadr ), the tail of the tail of a
list ( cddr ), etc.
The basic naming convention is easy: The a's and d's represent
the heads and tails of lists, so
(car (cdr (car x) ) ) could be written as: (cadar x)
To get some practice with list-accessing functions, try typing in the
following (except all on one line if you're using the console ); use
different variations of car and
cdr to access the different elements of the list:
(let* (
(x '( (1 2 (3 4 5) 6) 7 8 (9 10) )
)
)
; place your car/cdr code here
)
Try accessing the number 3 in the list using only two function
calls. If you can do that, you're on your way to becoming a
Script-Fu Master!
Note
In Scheme, a semicolon ( ; ) marks a comment. It, and
anything that follows it on the same line, are ignored by the
script interpreter, so you can use this to add comments to jog
your memory when you look at the script later.
3.2. Variables And Functions 3.4. Your First Script-Fu Script  Report an error in Bugzilla  3. 7. Your script and its working 3.7. Your script and its working 3. A Script-Fu Tutorial  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 7. Your script and its working 3.7. 1. What you write Below the complete script:
( script-fu-register
"script-fu-text-box" ;func name
"Text Box" ;menu label
"Creates a simple text box, sized to fit\
around the user's choice of text,\
font, font size, and color." ;description
"Michael Terry" ;author
"copyright 1997, Michael Terry;\
2009, the GIMP Documentation Team" ;copyright notice
"October 27, 1997" ;date created
"" ;image type that the script works on
SF-STRING "Text" "Text Box" ;a string variable
SF-FONT "Font" "Charter" ;a font variable
SF-ADJUSTMENT "Font size" '(50 1 1000 1 10 0 1)
;a spin-button
SF-COLOR "Color" '(0 0 0) ;color variable
SF-ADJUSTMENT "Buffer amount" '(35 0 100 1 10 1 0)
;a slider
)
( script-fu-menu-register "script-fu-text-box" " & lt;Image & gt;/ File/Create/Text")
( define (script-fu-text-box inText inFont inFontSize inTextColor inBufferAmount)
( let*
(
; define our local variables
; create a new image:
(theImageWidth 10)
(theImageHeight 10)
(theImage )
(theImage
(car
(gimp-image-new
theImageWidth
theImageHeight
RGB
)
)
)
(theText) ;a declaration for the text
(theBuffer) ; create a new layer for the image
( theLayer
(car
(gimp-layer-new
theImage
theImageWidth
theImageHeight
RGB-IMAGE
"layer 1"
100
NORMAL
)
)
)
) ;end of our local variables
( gimp-image-add-layer theImage theLayer 0)
( gimp-context-set-background '(255 255 255) )
(gimp-context-set-foreground inTextColor)
( gimp-drawable-fill theLayer BACKGROUND-FILL)
( set! theText
(car
(gimp-text-fontname
theImage theLayer
0 0
inText
0
TRUE
inFontSize PIXELS
"Sans")
)
)
( set! theImageWidth (car (gimp-drawable-width theText) ) )
(set! theImageHeight (car (gimp-drawable-height theText) ) )
(set! theBuffer (* theImageHeight (/ inBufferAmount 100) ) )
(set! theImageHeight (+ theImageHeight theBuffer theBuffer) )
(set! theImageWidth (+ theImageWidth theBuffer theBuffer) )
( gimp-image-resize theImage theImageWidth theImageHeight 0 0)
(gimp-layer-resize theLayer theImageWidth theImageHeight 0 0)
( gimp-layer-set-offsets theText theBuffer theBuffer)
(gimp-display-new theImage)
(list theImage theLayer theText)
)
)
3.7.2. What you obtain Figure 13.5. And the result on the screen. 3.6. Extending The Text Box Script Part III. Function Reference
 Report an error in Bugzilla  3. 5. Giving Our Script Some Guts 3.5. Giving Our Script Some Guts 3. A Script-Fu Tutorial  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 5. Giving Our Script Some Guts
Let us continue with our training and add some functionality to our
script.
3.5.1. Creating A New Image
In the previous lesson, we created an empty function and registered it
with GIMP . In this lesson, we want to provide
functionality to our script — we want to create a new image ,
add the user's text to it and resize the image to fit the text exactly.
Once you know how to set variables, define functions and access list
members, the rest is all downhill — all you need to do is
familiarize yourself with the functions available in
GIMP 's procedural database and call those functions
directly. So fire up the
Section 12.7, “The Procedure Browser” and let's get cookin'!
Let's begin by making a new image. We'll create a new variable,
theImage , set to the result of calling
GIMP 's
built-in function gimp-image-new .
As you can see from the DB Browser, the function
gimp-image-new takes three parameters — the
image's width, height and the type of image. Because we'll
later resize the image to fit the text , we'll make a 10x10 pixels
RGB
image. We'll store the image's width and sizes in some
variables, too, as we'll refer to and manipulate them later in
the script.
( define (script-fu-text-box inText inFont inFontSize inTextColor )
( let*
(
; define our local variables
; create a new image:
(theImageWidth 10)
(theImageHeight 10)
(theImage (car
(gimp-image-new
theImageWidth
theImageHeight
RGB
)
)
)
(theText) ;a declaration for the text
;we create later
Note: We used the value RGB to specify that the image
is an RGB image. We could have also used
0 , but RGB is more descriptive
when we glance at the code.
You should also notice that we took the head of the result of the
function call. This may seem strange, because the database explicitly
tells us that it returns only one value — the ID of the newly
created image. However, all GIMP functions return a
list, even if there is
only one element in the list, so we need to get the head of the list .
3.5.2. Adding A New Layer To The Image
Now that we have an image, we need to add a layer to it. We'll
call the gimp-layer-new function to create the
layer, passing
in the ID of the image we just created. (From now on, instead
of listing the complete function, we'll only list the lines
we're adding to it. You can see the complete script
here .)
Because we've declared all of the local variables we'll use,
we'll also close the parentheses marking the end of our
variable declarations:
; create a new layer for the image:
( theLayer
(car
(gimp-layer-new
theImage
theImageWidth
theImageHeight
RGB-IMAGE
"layer 1"
100
NORMAL
)
)
)
) ;end of our local variables
Once we have the new layer, we need to add it to the image:
( gimp-image-add-layer theImage theLayer 0)
Now, just for fun, let's see the fruits of our labors up until this
point, and add this line to show the new, empty image:
( gimp-display-new theImage)
Save your work, select
Filters → Script-Fu → Refresh Scripts ,
run the script and a new image should pop up. It will probably
contain garbage (random colors), because we haven't erased
it. We'll get to that in a second.
3.5.3. Adding The Text
Go ahead and remove the line to display the image (or comment
it out with a ( ; ) as the first character of the line).
Before we add text to the image, we need to set the background
and foreground colors so that the text appears in the color
the user specified. We'll use the
gimp-context-set-back/foreground functions:
( gimp-context-set-background '(255 255 255) )
(gimp-context-set-foreground inTextColor)
With the colors properly set, let's now clean out the garbage
currently in the image by filling the drawable with the background
color:
( gimp-drawable-fill theLayer BACKGROUND-FILL)
With the image cleared, we're ready to add some text:
( set! theText
(car
(gimp-text-fontname
theImage theLayer
0 0
inText
0
TRUE
inFontSize PIXELS
"Sans")
)
)
Although a long function call, it's fairly straightforward if
you go over the parameters while looking at the function's
entry in the DB Browser. Basically, we're creating a new text
layer and assigning it to the variable
theText .
Now that we have the text, we can grab its width and height and resize
the image and the image 's layer to the text's size:
( set! theImageWidth (car (gimp-drawable-width theText) ) )
(set! theImageHeight (car (gimp-drawable-height theText) ) )
(gimp-image-resize theImage theImageWidth theImageHeight 0 0)
(gimp-layer-resize theLayer theImageWidth theImageHeight 0 0)
If you're like me, you're probably wondering what a drawable is when
compared to a layer. The difference between the two is that a drawable
is anything that can be drawn into, including layers but also
channels, layer masks, the selection, etc; a layer is a more specific
version of a drawable. In most cases, the distinction is not
important.
With the image ready to go, we can now re-add our display line:
( gimp-display-new theImage)
Save your work, refresh the database and give your first script a run!
3.5.4. Clearing The Dirty Flag
If you try to close the image created without first saving the file,
GIMP will ask you if you want to save your work
before you close the
image. It asks this because the image is marked as dirty, or unsaved.
In the case of our script, this is a nuisance for the times when we
simply give it a test run and don't add or change anything in the
resulting image — that is, our work is easily reproducible in
such a simple script, so it makes sense to get rid of this dirty flag.
To do this, we can clear the dirty flag after displaying the image:
(gimp-image-clean-all theImage)
This will set dirty count to 0, making it appear to be a
“ clean ” image.
Whether to add this line or not is a matter of personal taste. I use
it in scripts that produce new images, where the results are trivial,
as in this case. If your script is very complicated, or if it works on
an existing image, you will probably not want to use this function.
3.4. Your First Script-Fu Script 3. 6. Extending The Text Box Script  Report an error in Bugzilla  3. A Script-Fu Tutorial 3. A Script-Fu Tutorial Chapter 13. Scripting  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. A Script-Fu Tutorial
In this training course, we'll introduce you to the fundamentals of Scheme
necessary to use Script-Fu, and then build a handy script that you can add
to your toolbox of scripts. The script prompts the user for some text,
then creates a new image sized perfectly to the text. We will then enhance
the script to allow for a buffer of space around the text. We will
conclude with a few suggestions for ways to ramp up your knowledge of
Script-Fu.
Note
This section as adapted from a tutorial written for the
GIMP 1 User
Manual by Mike Terry.
3.1. Getting Acquainted With Scheme 3.1.1. Let's Start Scheme'ing The first thing to learn is that:
Every statement in Scheme is surrounded by parentheses ().
The second thing you need to know is that:
The function name/operator is always the first item in the
parentheses, and the rest of the items are parameters to the
function.
However, not everything enclosed in parentheses is a function —
they can also be items in a list — but we'll get to that later.
This notation is referred to as prefix notation, because the function
prefixes everything else. If you're familiar with postfix notation, or
own a calculator that uses Reverse Polish Notation (such as most HP
calculators), you should have no problem adapting to formulating
expressions in Scheme.
The third thing to understand is that:
Mathematical operators are also considered functions, and thus are
listed first when writing mathematical expressions.
This follows logically from the prefix notation that we just
mentioned.
3.1.2. Examples Of Prefix, Infix, And Postfix Notations
Here are some quick examples illustrating the differences between
prefix , infix , and
postfix notations. We'll add a 1 and 23 together:
Prefix notation: + 1 23
(the way Scheme will want it)
Infix notation: 1 + 23
(the way we “ normally ” write it)
Postfix notation: 1 23 +
(the way many HP calculators will want it)
3.1.3. Practicing In Scheme
Now, let's practice what we have just learned. Start up
GIMP , if you have not already done so, and choose
Filters → Script-Fu → Console .
This will start up the Script-Fu Console window, which allows us to
work interactively in Scheme. In a matter of moments, the Script-Fu
Console will appear:
3.1.4. The Script-Fu Console Window
At the bottom of this window is an entry-field ought to be entitled
Current Command .
Here, we can test out simple Scheme commands interactively. Let's
start out easy, and add some numbers:
(+ 3 5)
Typing this in and hitting Enter
yields the expected answer of 8 in the center window.
Figure 13.3. Use Script-Fu Console.
Now, what if we wanted to add more than one number? The
“ + ”
function can take two or more arguments, so this is not a problem:
(+ 3 5 6) This also yields the expected answer of 14.
So far, so good — we type in a Scheme statement and it's executed
immediately in the Script-Fu Console window. Now for a word of
caution…
3.1.5. Watch Out For Extra Parentheses
If you're like me, you're used to being able to use extra parentheses
whenever you want to — like when you're typing a complex
mathematical
equation and you want to separate the parts by parentheses to make it
clearer when you read it. In Scheme, you have to be careful and not
insert these extra parentheses incorrectly. For example, say we wanted
to add 3 to the result of adding 5 and 6 together:
3 + (5 + 6) + 7 = ?
Knowing that the + operator can take a list of numbers to add, you
might be tempted to convert the above to the following:
(+ 3 (5 6) 7)
However, this is incorrect — remember, every statement in Scheme
starts and ends with parens, so the Scheme interpreter will think that
you're trying to call a function named “ 5 ” in the second
group of parens, rather than summing those numbers before adding them
to 3.
The correct way to write the above statement would be: (+ 3 (+ 5 6) 7) 3.1.6. Make Sure You Have The Proper Spacing, Too
If you are familiar with other programming languages, like C/C++, Perl
or Java, you know that you don't need white space around mathematical
operators to properly form an expression:
3+5, 3 +5, 3+ 5
These are all accepted by C/C++, Perl and Java compilers. However, the
same is not true for Scheme. You must have a space after a
mathematical operator (or any other function name or operator) in
Scheme for it to be correctly interpreted by the Scheme interpreter.
Practice a bit with simple mathematical equations in the Script-Fu
Console until you're totally comfortable with these initial concepts.
2.6. Image-Dependent Scripts 3.2. Variables And Functions
 Report an error in Bugzilla 
2. 2. Adding or subtracting selections 2.2. Adding or subtracting selections 2. Creating and Using Selections  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Adding or subtracting selections
Tools have options that you can configure.
Each selection tool allows you to set the selection mode. The
following selection modes are supported:
Replace is the most used selection mode. In replace mode,
a selection replaces any existing selection.
Add mode, causes new selections to be added to any existing
selection . Press and hold the Shift key while
making a selection to temporarily enter add mode.
Subtract mode, causes new selections to be removed from any existing
selection. Press and hold the Ctrl key while
making a selection to temporarily enter subtract mode.
Intersect mode, causes areas in both the new and
existing selection to become the new selection.
Press and hold both the Shift and
Ctrl key while
making a selection to temporarily enter intersect mode.
Figure 7.8. Enlarging a rectangular selection with the Lasso
The figure shows an existing rectangular selection.
Select the Lasso. While pressing the Shift
key, make a free hand selection that includes the existing selection.
Release the mouse button and areas are included in the selection.
Note
To correct selection defects precisely, use the
Quick Mask .
2. Creating and Using Selections 3. The QuickMask
 Report an error in Bugzilla 
2. Creating and Using Selections 2. Creating and Using Selections Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Creating and Using Selections 2. 1. Moving a Selection
Rectangular and elliptical selections have two modes. The default
mode has handles on the selection. If you click the selection or
press the Enter key ,the handles disappear leaving
only the dotted outline (marching ants). The other selection tools have
different behaviour.
2.1.1. Moving rectangular and elliptical selections
If you click-and drag a selection with handles, you move the
selection outline, and you don't move the contents of rectangular or
elliptic selections.
Select the Move tool and set
the options to move the selection; the tool supports moving the
selection, path, or layer.
Figure 7.5. Moving selection outline
Most systems support moving the selection using the arrow keys.
The precise behavior is system dependent. If the arrow keys do not
cause the selection to move, try hovering the mouse cursor over the
selection first. Press and hold the Alt (or
Ctrl + Alt ,
Shift + Alt , or
Alt ). One combination may move the selection by one
pixel, and another by 25 pixels each step. Hover the mouse cursor over
a side or corner handle, and the arrow keys and combinations can
change the size of the selection .
If you click -and-drag the selection without handles, you create a new
selection! To move the selection contents, you have to
hold down
Ctrl + Alt
keys and click-and-drag the selection . This makes the original
place empty. A floating selection is created.
The required key commands may differ on your system, look in the
status bar to see if another combination is specified; for
example,
Shift + Ctrl + Alt .
Figure 7.6.
Moving a selection and its content , emptying the original place
hold down
Shift + Alt
keys and click-and-drag the selection to move without emptying
the original place . A floating selection is created.
Figure 7.7.
Moving a selection and its content without emptying the original
place
Note
On some systems, you must push Alt before
Shift or Ctrl . On these
systems, pressing Shift or Ctrl
first, causes GIMP to enter a mode that adds or subtract from the
current selection — after
that, the Alt key is ineffective!
2.1.2. Moving the other selections
The other selections (Lasso, Magic wand, By Color) have no handle.
Click-and dragging them doesn't move them. To move their contents, as
with rectangular and elliptical selections, you have to hold down
Ctrl + Alt keys
or Shift + Alt
and click-and-drag.
If you use keyboard arrow keys instead of click-and-drag, you move
the outline.
2.1.3. Other method Note
You can also use a more roundabout method to move a selection. Make
it floating. Then you can move its content, emptying the origin, by
click-and-dragging or keyboard arrow keys. To move without emptying,
use copy-paste.
Chapter 7. Painting with GIMP 2.2. Adding or subtracting selections  Report an error in Bugzilla 
4. How to Set Your Tile Cache 4. How to Set Your Tile Cache Chapter 12. Enrich my GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. How to Set Your Tile Cache
During the data processing and manipulation of pictures, GIMP becomes
in the need of much main memory. The more is available the better is.
GIMP uses the operating system memory available
resources as effectively as possible, striving to maintain the work on
the pictures fast and comfortable for the user. That Data memory,
during the treatment, is organized in buffered blocks of graphic data,
which could exist in two different forms of data memory: in the slow not
removable disk or in the fast main RAM memory. GIMP uses preferably the
RAM, and when it runs short of this memory, it uses the hard disk for the
remaining data. These chunks of graphic data are commonly referred to as
"tiles" and the entire system is called "tile cache".
A low value for tile cache means that GIMP sends data to the disk very
quickly, not making real use of the available RAM, and making the disks
work for no real reason. Too high a value for tile cache, and other
applications start to have less system resources, forcing them to use swap
space, which also makes the disks work too hard; some of them may even
terminate or start to malfunction due lack of RAM.
How do you choose a number for the Tile Cache size? Here are some tips to
help you decide what value to use, as well as a few tricks:
The easiest method is to just forget about this and hope the default
works. This was a usable method when computers had little RAM, and
most people just tried to make small images with GIMP while running
one or two other applications at the same time. If you want something
easy and only use GIMP to make screenshots and logos, this is probably
the best solution.
If you have a modern computer with plenty of memory–say, 512 MB or
more–setting the Tile Cache to half of your RAM will probably give
good performance for GIMP in most situations without depriving other
applications. Probably even 3/4 of your RAM would be fine.
Ask someone to do it for you, which in the case of a computer serving
multiple users at the same time can be a good idea: that way the
administrator and other users do not get mad at you for abusing the
machine, nor do you get a badly underperforming GIMP. If it is your
machine and only serves a single user at a given time, this could mean
money, or drinks, as price for the service.
Start changing the value a bit each time and check that it goes faster
and faster with each increase, but the system does not complain about
lack of memory. Be forewarned that sometimes lack of memory shows up
suddenly with some applications being killed to make space for the
others.
Do some simple math and calculate a viable value. Maybe you will have
to tune it later, but maybe you have to tune it anyway with the other
previous methods. At least you know what is happening and can get the
best from your computer.
Let's suppose you prefer the last option, and want to get a good value to
start with. First, you need to get some data about your computer. This
data is the amount of RAM installed in your system, the operating system's
swap space available, and a general idea about the speed of the disks that
store the operating system's swap and the directory used for GIMP's swap.
You do not need to do disk tests, nor check the RPM of the disks, the
thing is to see which one seems clearly faster or slower, or whether all
are similar. You can change GIMP's swap directory in the Folders page of
the Preferences dialog.
The next thing to do is to see how much resources you require for other
apps you want to run at the same time than GIMP. So start all your tools
and do some work with them, except GIMP of course, and check the usage.
You can use applications like free or top, depending in what OS and what
environment you use. The numbers you want is the memory left, including
file cache. Modern Unix keeps a very small area free, in order to be able
to keep large file and buffer caches. Linux's free
command does the maths for you: check the column that says
“ free ” , and the line “ -/+ buffers/cache ” .
Note down also the free swap.
Now time for decisions and a bit of simple math. Basically the concept is
to decide if you want to base all Tile Cache in RAM, or RAM plus operating
system swap:
Do you change applications a lot? Or keep working in GIMP for a long
time? If you spend a lot of time in GIMP, you can consider free RAM
plus free swap as available; if not, you need to go to the following
steps. (If you 're feeling unsure about it, check the following steps.)
If you are sure you switch apps every few minutes, only count the free
RAM and just go to the final decision; no more things to check.
Does the operating system swap live in the same physical disk as GIMP
swap? If so, add RAM and swap. Otherwise go to the next step.
Is the disk that holds the OS swap faster or the same speed as the
disk that holds the GIMP swap? If slower, take only the free RAM; if
faster or similar, add free RAM and swap.
You now have a number, be it just the free RAM or the free RAM plus
the free OS swap. Reduce it a bit, to be on the safe side, and that is
the Tile Cache you could use as a good start.
As you can see, all is about checking the free resources, and decide if
the OS swap is worth using or will cause more problems than help.
There are some reasons you want to adjust this value, though. The basic
one is changes in your computer usage pattern, or changing hardware. That
could mean your assumptions about how you use your computer, or the speed
of it, are no longer valid. That would require a reevaluation of the
previous steps, which can drive you to a similar value or a completely
new value.
Another reason to change the value is because it seems that GIMP runs too
slowly, while changing to other applications is fast: this means that GIMP
could use more memory without impairing the other applications. On the
other hand, if you get complaints from other applications about not having
enough memory, then it may benefit you to not let GIMP hog so much of it.
If you decided to use only RAM and GIMP runs slowly, you could try
increasing the value a bit, but never to use also all the free swap. If
the case is the contrary, using both RAM and swap, and you have problems
about lack of resources, then you should decrease the amount of RAM
available to GIMP.
Another trick is to put the Swap Dir on a very fast disk, or on a
different disk than the one where most of your files
reside. Spreading the operating
system swap file over multiple disks is also a good way to speed
things up, in general. And of course, you might have to buy more RAM
or stop using lots of programs at the same time: you can not
expect to edit a poster on a computer with 16MB and be fast.
You can also check what memory requirements your images have. The larger
the images, and the number of undoes, the more resources you need. This
is another way to choose a number, but it is only good if you always work
with the same kind of images, and thus the real requirements do not vary.
It is also helpful to know if you will require more RAM and/or disk space.
3. Rendering a Grid 5. Creating Shortcuts to Menu Functions  Report an error in Bugzilla  14. Drawing Simple Objects 14. Drawing Simple Objects Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  14. Drawing Simple Objects In this section, you will learn how to create simple objects in
GIMP . It's pretty easy once you figure out how to do
it. GIMP provides a huge set of
Tools and Shortcuts which most new users
get lost in.
14. 1. Drawing a Straight Line
Let's begin by painting a straight line. The easiest way to create a
straight line is by using your favorite
brush tool , the mouse and
the keyboard.
Procedure 7. 1. Drawing a Straight Line Figure 7.35. A new image
The dialog shows a new image, filled with a white background.
Create a new image .
Select your favorite
brush tool or use the
pencil , if in doubt.
Select a foreground
color , but be sure that the foreground and background
colors are different.
Figure 7. 36. The start of the straight line
The dialog shows a new image, with the first dot which
indicates the start of the straight line. The dot has a black
foreground color.
Create a starting point by clicking on the
image display area
with the left mouse button. Your canvas should look
similar to Figure 7.35, “A new image” .
Figure 7.37. The helpline
The screenshot shows the helpline, which indicates how the
finished line will look.
Now, hold down the Shift button on your
keyboard and move the mouse away from the starting point you
created. You'll see a thin line indicating how the line will
look.
Figure 7.38. The line after the second click
The line created appears in the image window after drawing the
second point (or end point), while the Shift
key is still pressed.
If you're satisfied with the direction and length of the line,
click the left mouse button again to finish the line. The
GIMP displays a straight line now. If the
line doesn't appear, check the foreground and background
colors and be sure that you kept the Shift
key pressed while painting. You can keep creating lines by
continuing to hold the Shift key and creating
additional end points.
13. Presets 14.2. Creating a Basic Shape  Report an error in Bugzilla 
3. Text 3. Text Chapter 9. Text Management  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. Text 3.1. Embellishing Text Figure 9.7. Fancy text
Four fancy text items created using logo scripts: “ alien
neon ” , “ bovination ” , “ frosty ” ,
and “ chalk ” . Default settings were used for
everything except font size.
There are many things you can do to vary the appearance of text beyond
just rendering it with different fonts or different colors. By
converting a text item to a selection or a path , you can fill it, stroke
the outlines, transform it, or generally apply the whole panoply of
GIMP tools to get interesting effects. As a demonstration of some of the
possibilities , try out the "logo" scripts at
File → Create → Logos .
Each of these scripts allows you to enter some text, and then creates
a new image showing a logo constructed out of that text. If you would
like to modify one of these scripts, or construct a logo script of your
own, the Using Script-Fu
and
Script-Fu Tutorial
sections should help you get started. Of course, you don't need
Script-Fu to create these sorts of effects, only to automate them.
2. Text Tool Box 3.2. Adding Fonts
 Report an error in Bugzilla  9.2. Creating a brush quickly 9.2. Creating a brush quickly 9. Varying brush size  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  9.2. Creating a brush quickly Two methods to create a new brush easily:
First, the “ superfast ” method. You have an image area
you want make a brush from it, to be used with a tool like pencil,
airbrush... Select it with the rectangular (or elliptical) select
tool, then do a Copy of this selection and
immediately you can see this copy in the first position of the Brush
Dialog, and its name is “ Clipboard ” . It is immediately
usable.
Figure 7.21. Selection becomes a brush after copying The second method is more elaborate.
Do
File → New
with, for example, a width and a length of 35 pixels
and in the advanced options a
Color Space in
Gray Level and
Fill with: white .
Zoom on this new image to enlarge it and draw on it with a black
pencil.
Save it with a .gbr extension in the directory
/home/name_of_user/.gimp-2.8/brushes/ .
In the Brushes dialog window, click on the button
Refresh brushes
.
And your marvellous brush appears right in the middle of the other
brushes. You can use it immediately, without starting GIMP again.
Figure 7.22. Steps to create a brush Draw image, save as brush Refresh brushes Use the brush 9. Varying brush size 10. Gradients
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9. Varying brush size 9. Varying brush size Chapter 7. Painting with GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  9. Varying brush size
From GIMP -2.4, all brushes have a variable size.
9.1. How to vary the height of a brush
You can get the brush size varying in three ways:
Using the Scale slider of the tool
that uses the brush. Pencil, Paintbrush, Eraser, Airbrush,
Clone, Heal, Perspective Clone, Blur/Sharpen and Dodge/Burn tools
have a slider to vary brush size.
Figure 7.20. The Scale slider By programming the mouse wheel:
In the main window of GIMP, click on
Edit → Preferences .
In the left column of the new window, select
Input Devices → Input Controllers .
You can see
Additional Input Controllers ,
with two columns:
Available Controllers and
Active Controllers .
In the column
Active Controllers , double-click the
Main Mouse Wheel button.
Then, you see a new window:
Configure Input Controller .
In the left column Event ,
click Scroll Up to get it highlighted.
Click the Edit button
(at the bottom middle of the list).
You can see the window
Select Controller Event Action .
Drop-down the
Tools item, by clicking the small
triangle on its left.
In the left column Action ,
click Increase Brush Scale to highlight
it, then click the OK button.
Now, in front of
Scroll Up is display
tools-paint-brush-scale-increase .
Close the window.
With the same method, program
Scroll Down with
Decrease Brush Scale .
Don't forget to click the
OK button of the main window of
Preferences .
After these somewhat long explanations, you can use your mouse
wheel to vary size brush. For example, choose the pencil tool
with the “ Circle ” brush. Set the
pointer in the image window, use the mouse wheel, in the two
directions, you can see the “ Circle ” shrinking or
stretching.
You can program the “ Up ” and “ Down ”
arrow keys of the keyboard .
The method is similar to that of the mouse wheel. The only
differences are:
In the column
Active Controllers , double-click
Main Keyboard .
In the column Event , click
Cursor Up for the first key, and
Cursor Down for the second key.
Then, use the two keys (Up arrow and Down arrow) and the result
is the same as you got with the mouse wheel.
8. The GIH Dialog Box 9.2. Creating a brush quickly  Report an error in Bugzilla  2. 2. Reducing the File Size Even More 2.2. Reducing the File Size Even More 2. Preparing your Images for the Web  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Reducing the File Size Even More
If you want to reduce the size of your image a bit more, you could
convert your image to Indexed mode. That means that all of the colors
will be reduced to only 256 values. Do not convert images with
smooth color transitions or gradients to indexed mode, because
the original smooth gradients are typically converted into a
series of bands. Indexed mode is not recommended for photographs
because after the conversion, they typically look coarse and
grainy.
Figure 6.8. The indexed image
An indexed image can look a bit grainy. The left image is Wilber
in its original size, the right image is zoomed in by 300 percent.
Use the command described in Section 6.3, “Mode”
to convert an RGB image to indexed mode.
After you convert an image to indexed mode, you are once
again able to export the
image in PNG
format .
2. Preparing your Images for the Web 2. 3. Saving Images with Transparency  Report an error in Bugzilla  2. 3. Saving Images with Transparency 2. 3. Saving Images with Transparency 2. Preparing your Images for the Web  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 3. Saving Images with Transparency
There are two different approaches used by graphic file formats
for supporting transparent image areas: simple binary transparency
and alpha transparency. Simple binary transparency is supported
in the GIF format; one color
from the indexed color palette is marked as the transparent color.
Alpha transparency is supported in the
PNG format; the
transparency information is stored in a separate channel, the
Alpha channel .
Note
The GIF format is rarely used
because PNG supports all the features of GIF with additional
features (e.g., alpha transparency). Nevertheless, GIF is
still used for animations.
Procedure 6.1.
Creating an Image with Transparent Areas (Alpha Transparency)
First of all, we will use the same image as in the previous
tutorials, Wilber the GIMP mascot.
Figure 6.9. The Wilber image opened in RGBA mode
To export an image with alpha transparency, you must have an alpha
channel. To check if the image has an alpha channel , go to the
channel dialog and
verify that an entry for “ Alpha ” exists, besides
Red, Green and Blue. If this is not the case ,
add a new alpha channel
from the layers menu;
Layer + Transparency → Add Alpha Channel .
The original XCF file contains background layers that you can
remove. GIMP comes with standard filters
that supports creating gradients; look
under Filters + Light and Shadow .
You are only limited by your imagination. To
demonstrate the capabilities of alpha transparency, a
soft glow in the background around Wilber is shown.
After you're done with your image, you can
export it in
PNG format .
Figure 6.10. The Wilber image with transparency
Mid-Tone Checks in the background layer represent the transparent
region of the exported image while you are working on it in
GIMP .
2.2. Reducing the File Size Even More Chapter 7. Painting with GIMP  Report an error in Bugzilla  2. Preparing your Images for the Web 2. Preparing your Images for the Web Chapter 6. Getting Images out of GIMP  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. Preparing your Images for the Web One of the most common uses for GIMP ,
is to prepare images for web sites. This means that
images should look as nice as possible while keeping the file
size as small as possible. This step-by-step guide demonstrates
how to create small files with minimal loss of
image quality.
2.1. Images with an Optimal Size/Quality Ratio
An optimal image for the web depends upon the image type and the file
format. Use JPEG for
Photographs because they usually have many colors and great detail.
An image with fewer colors, such as a button, icon, or screenshot, is
better suited to the
PNG
format.
First, open the image as usual. I have opened our Wilber as an
example image.
Figure 6.7. The Wilber image opened in RGBA mode
The image is now in RGB mode, with an additional
Alpha channel
(RGBA). There is usually no need to have an alpha channel for your
web image. You can remove the alpha channel by
flattening the image .
A photograph rarely has an alpha channel, so the image will open
in RGB mode rather than RGBA mode; and you won't have to remove
the alpha channel.
Note
If the image has a soft transition into the transparent areas, you
should not remove the alpha channel, since the information
used for the transition is not be saved in the file.
To export an image with transparent areas that do not have a
soft transition, (similar to
GIF ),
remove the alpha channel.
After you have flattened the image,
export the image
in the PNG format
for your web site.
Note
You can export your image in the PNG format with the default settings.
Always using maximum compression when creating the image.
Maximum compression has no affect on image quality or the time
required to display the image, but it does take longer to export.
A JPEG image, however,
loses quality as the compression is increased.
If your image is a photograph with lots of colors, you should
use jpeg. The main thing is to find the best
tradeoff between quality and compression. You can find more
information about this topic in Section 1.2.2, “Export Image as JPEG” .
Chapter 6. Getting Images out of GIMP 2.2. Reducing the File Size Even More  Report an error in Bugzilla 
5. 3. Dot for Dot 5.3. Dot for Dot 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 3. Dot for Dot
The Dot for Dot command enables and disables
“ Dot for Dot ” mode. If it is enabled (checked) and the
zoom factor is 100%, every pixel in the image is displayed as one pixel
on the screen. If it is disabled, the image is displayed at its
“ real ” size, the size it will have when it is printed .
The example below will illustrate this. Imagine the following image
properties:
Image size: 100x100 pixels Image resolution: 300 ppi (pixels per inch)
Image displayed with Zoom=100%, “ Dot for Dot ” enabled :
100x100 pixels
Image displayed with Zoom=100%, “ Dot for Dot ” disabled :
100 pixels ÷ 300 ppi = 1/3 inch ≅ 0.85 cm
For Dot for Dot mode to work properly, the resolution of the image
must be the same as the screen resolution in the
Preferences menu .
Enabling this mode is recommended if you are working on icons and web
graphics. If you are working on images intended to be printed, you should
disable Dot-for-Dot mode.
 5. 3. 1. Activating the Command
You can access this command from the image menubar through
View → Dot for Dot .  5. 2. New View 5. 4. Zoom
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5. 6. Full Screen 5. 6. Full Screen 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 6. Full Screen
The Fullscreen command enables and disables
displaying the image window on the entire screen. When it is enabled,
the image window takes up the whole screen, but the image stays the
same size. When you enable full-screen mode, the menubar may not be
displayed, but if this happens, you can right-click on the image to
access the image menu. You can set the default appearance for
full-screen mode in the
Preferences
menu.
Pressing TAB key toggles the visibility of all present
docks.
Note
If you use GIMP
on an Apple computer, full-screen mode may not work, since Apple doesn't
provide the necessary functionality. Instead, you can maximize the image
window by clicking on the Green Button ,
so the image occupies most of the screen.
 5. 6. 1. Activating the Command
You can access this command from the image menubar through
View → Full Screen ,
or by using the keyboard shortcut F11 .
In multi-window mode, you can also get it by double-clicking on the
title bar of the image window.  5. 5. Shrink Wrap 5. 7. Navigation Window
 Report an error in Bugzilla  5. The “View” Menu 5. The “ View ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. The “ View ” Menu 5. 1. Introduction to the “ View ” Menu Figure 16.41. Contents of the View menu
This section describes the View menu, which contains
commands that affect the visibility or appearance of the image and
various elements of the interface.
Note
Besides the commands described here, you may also find other entries in
the menu. They are not part of GIMP itself,
but have been added by extensions (plug-ins). You can find information
about the functionality of a Plugin by referring to its documentation.
4.18. To Path 5.2. New View
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5. 7. Navigation Window 5. 7. Navigation Window 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 7. Navigation Window
The Navigation Window command opens the
navigation window . This
allows you to easily navigate through the image, to set zoom levels and
to move the visible parts of the image. You can find more information
about using it in the
Navigation dialog chapter.
 5. 7. 1. Activating the Command
You can access this command from the image menubar through
View → Navigation Window ,
You can also access it more rapidly by clicking on the
icon in the lower right corner of the image window.  5. 6. Full Screen 5. 8. Display Filters
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5. 2. New View 5. 2. New View 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 2. New View
The New View command creates a new image
window for the current image, which you can set up differently from
the existing display. You can create multiple views of any image, which
are numbered .1, .2, etc., but only the zoom factor and other viewing
options may be different. Any changes, other than viewing changes,
which you make in one window also appear in the other displays which
show the same image. The new views are not separate image files; they
are simply different aspects of the same image. You might use multiple
views, for example, if you were working on individual pixels at a high
zoom factor. You could then see the effects your changes would have on
the image at a normal size.
 5. 2. 1. Activating the Command
You can access this command from the image menubar through
View → New View .  5. The “ View ” Menu 5. 3. Dot for Dot
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5. 18. Padding Color 5. 18. Padding Color 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 18. Padding Color Figure 16.51. Contents of the “ Padding Color ” submenu
You can change the color of the canvas which surrounds the image by
using the Padding Color command. The canvas
is the surface the image lies on. It looks like a frame around the
image in the image window . This is just a matter of personal
preference, since the padding color does not have any effect on the
image itself. Please note that this color is not the same as the color
used by the Fill tool.
 5.18. 1. Activating the submenu
You can access this submenu from the image menubar through
View → Padding Color .  5. 18. 2. “ Padding Color ” Options From Theme
The color of the theme defined in
Preferences Theme is used.
Light/Dark Check Color
The check representing transparency, which is defined in
Preferences Display is
used.
Select Custom Color
Opens the Color Selector window to let you choose a color to use.
As in Preferences
The color selected in the
Image Window
Appearance is used.
5.17. Snap to Active Path 5.19. Show Menubar
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5. 12. Show Grid 5. 12. Show Grid 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 12. Show Grid
By using the Show Grid command, you can
enable and disable displaying the grid. When you enable it, the grid
overlays the image and makes it easier for you to line up selected image
elements.
You can set the default for the grid in the
Image Window Appearance
dialog.
Tip
See also the
Configure Grid
command and the
Snap to Grid command .
 5. 12. 1. Activating the Command
You can access this command from the image menubar through
View → Show Grid .  5. 11. Show Guides 5. 13. Show Sample Points
 Report an error in Bugzilla 
5. 11. Show Guides 5. 11. Show Guides 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 11. Show Guides
The Show Guides command enables and disables
displaying of Guides in the
image window.
You can set the default for the guides in the
Image Window Appearance
dialog.
 5. 11. 1. Activating the Command
You can access this command from the image menubar through
View → Show Guides ,
or by using the keyboard shortcut
Shift + Ctrl + T .  5. 10. Show Layer Boundary 5. 12. Show Grid
 Report an error in Bugzilla  5. 10. Show Layer Boundary 5. 10. Show Layer Boundary 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 10. Show Layer Boundary The Show Layer Boundary command enables and
disables displaying the yellow dotted line that surrounds a layer
in the image window. The dotted line is actually only visible when the
layer is smaller than the image window . When the layer is the same size
as the image window, the layer boundary is obscured by the image border.
You can set the default for the layer boundary in the
Image Window Appearance
dialog.
 5. 10. 1. Activating the Command
You can access this command from the image menubar through
View → Show Layer Boundary .  5. 9. Show Selection 5. 11. Show Guides
 Report an error in Bugzilla  5. 19. Show Menubar 5. 19. Show Menubar 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 19. Show Menubar
The Show Menubar command enables and disables
displaying the menubar. It may be useful to disable it if you are
working in full-screen mode .
If the menubar is not displayed, you can right-click on the image
to access the menubar entries.
You can set the default for the menubar in the
Image Window Appearance
dialog.
 5. 19. 1. Activating the Command
You can access this command from the image menubar through
View → Show Menubar .  5. 18. Padding Color 5. 20. Show Rulers
 Report an error in Bugzilla 
5. 20. Show Rulers 5. 20. Show Rulers 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 20. Show Rulers
The Show Rulers command enables and disables
displaying the rulers. It may be useful to disable them if you are
working in full-screen mode .
You can set the default for the rulers in the
Image Window Appearance
dialog.
 5. 20. 1. Activating the Command
You can access this command from the image menubar through
View → Show Rulers ,
or by using the keyboard shortcut
Shift + Ctrl + R .  5. 19. Show Menubar 5. 21. Show Scrollbars
 Report an error in Bugzilla 
5. 13. Show Sample Points 5. 13. Show Sample Points 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 13. Show Sample Points
This command enables and disables showing the sample points in the image
window. Sample points are used to display color informations of up to four
pixels in the sample points
dialog .
 5. 13. 1. Activating the Command
You can access this command from the image menubar through
View → Show Sample Points .  5. 12. Show Grid 5. 14. Snap to Guides
 Report an error in Bugzilla  5. 21. Show Scrollbars 5.21. Show Scrollbars 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 21. Show Scrollbars
The Show Scrollbars command enables and
disables displaying the scrollbars. It may be useful to disable them if
you are working in
full-screen mode .
You can set the default for the scrollbars in the
Image Window Appearance
dialog.
 5. 21. 1. Activating the Command
You can access this command from the image menubar through
View → Show Scrollbars .  5. 20. Show Rulers 5. 22. Show Statusbar
 Report an error in Bugzilla 
5. 9. Show Selection 5. 9. Show Selection 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 9. Show Selection
The Show Selection command enables and
disables displaying the dotted line surrounding the selection in the
image window. Please note that the selection still exists, even if
displaying this line is disabled.
You can set the default for displaying the selection in the
Image Window Appearance
dialog.
 5. 9. 1. Activating the Command
You can access this command from the image menubar through
View → Show Selection ,
or by using the keyboard shortcut
Ctrl + T .  5. 8. Display Filters 5. 10. Show Layer Boundary
 Report an error in Bugzilla 
5. 22. Show Statusbar 5.22. Show Statusbar 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 22. Show Statusbar
The Show Statusbar command enables and
disables displaying the status bar. It may be useful to disable it when
you are working in
full-screen mode .
You can set the default for the status bar in the
Image Window Appearance
dialog.
 5. 22. 1. Activating the Command
You can access this command from the image menubar through
View → Show Statusbar .  5. 21. Show Scrollbars 6. The “ Image ” Menu
 Report an error in Bugzilla 
5. 5. Shrink Wrap 5. 5. Shrink Wrap 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 5. Shrink Wrap
The Shrink Wrap command resizes the window
so that it is exactly the same size as the image at the current
zoom factor. If the image doesn't completely fit on the screen, the
image window is enlarged so that the largest possible part of the
image is shown. Please note that GIMP will
do this automatically if you set the “ Resize window on zoom ”
and “ Resize window on image size change ” options in the
Image Window page of
the Preferences dialog.
Note
Please note also that the behavior described here is not performed by
GIMP itself, but by the “ window
manager ” , a part of the operating system of your computer.
For that reason, the functionality described may be different on
your computer, or in the worst case, might not be available at all.
 5. 5. 1. Activating the Command
You can access this command from the image menubar through
View → Shrink Wrap ,
or by using the keyboard shortcut
Ctrl + J .  5. 4. Zoom 5. 6. Full Screen
 Report an error in Bugzilla  5. 16. Snap to Canvas 5. 16. Snap to Canvas 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 16. Snap to Canvas If this option is enabled , when you move a selection or a layer, they
appear to pull on the canvas edges when it approaches. This is useful for
accurate placement of image elements.
Note
Canvas edges are usually mingled with image edges: the canvas has, then,
the same size as the image . But you can change canvas size in
Image → Canvas Size .
 5. 16. 1. Activating the Command
You can access this command from the image menubar through
View → Snap to Canvas .  5. 15. Snap to Grid 5. 17. Snap to Active Path
 Report an error in Bugzilla  5. 15. Snap to Grid 5. 15. Snap to Grid 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 15. Snap to Grid The Snap to Grid command enables and disables
snap to grid. When snap to grid is enabled, the grid you set (see
Show Grid ) almost seems
magnetic; when you move a layer or selection, the grid points appear to
pull on it when it approaches. This is enormously useful for accurate
placement of image elements.
 5. 15. 1. Activating the Command
You can access this command from the image menubar through
View → Snap to Grid .  5. 14. Snap to Guides 5. 16. Snap to Canvas
 Report an error in Bugzilla  5. 14. Snap to Guides 5. 14. Snap to Guides 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 14. Snap to Guides
The Snap to Guides command enables and
disables snap to guides. When snap to guides is enabled, the guides
you set (see Show Guides )
almost seems magnetic; when you move a layer or selection, the guides
appear to pull on it when it approaches. This is enormously useful for
accurate placement of image elements.
 5. 14. 1. Activating the Command
You can access this command from the image menubar through
View → Snap to Guides .  5. 13. Show Sample Points 5. 15. Snap to Grid
 Report an error in Bugzilla  5. 17. Snap to Active Path 5.17. Snap to Active Path 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 17. Snap to Active Path If this option is enabled , when you move a selection or a layer, they
appear to pull on the next anchor point of the active path when it
approaches. This is useful for accurate placement of image elements.
 5. 17. 1. Activating the Command
You can access this command from the image menubar through
View → Snap to Path .  5. 16. Snap to Canvas 5. 18. Padding Color
 Report an error in Bugzilla 
5. 4. Zoom 5. 4. Zoom 5. The “ View ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 4. Zoom Figure 16.42.
The “ Zoom ” submenu of the “ View ” menu
The Zoom
submenu contains various commands which affect the magnification of the
image in the image window (zooming). Enlarging an image (zooming in) is
useful if you need to work with high precision, making pixel-level image
modifications or precise selections. On the other hand, reducing an image
(zooming out) is handy for getting an overall impression of the image and
seeing the results of changes which affect the entire image. Please note
that zooming is not undoable, since it does not affect the image data,
only the way it is displayed.
Tip
Besides the entries in this submenu, there is also a zoom pull-down menu
at the bottom edge of the image window ( if the
status bar is
displayed), where several preset zoom levels are available.
You can also make settings regarding zooming in the
Navigation dialog . You
can also use the Zoom tool
which lets you zoom a particular area of the image.
 5.4.1. Activate the Submenu
You can access this submenu from the image menubar through
View → Zoom .
Note that the “ Zoom ” label on the “ View ”
menu shows the current zoom factor, for example,
Zoom (100%) .  5.4.2. Contents of the “ Zoom ” submenu
The various “ Zoom ” submenu commands are described below,
along with their default keyboard shortcuts, if any.
Revert Zoom
(Shortcut: ` [grave
accent, “ backtick ” ]) This command will reset the zoom
factor to the previous value, which is also shown by this label,
for example Revert Zoom (100%) . If you never
changed the zoom factor of the active image, this entry is
insensitive and grayed out.
Zoom Out
( Shortcut: - ) Each time “ Zoom Out ”
is used, the zoom factor is decreased by about 30%. There is a
minimum zoom level of 0.39%.
Zoom In
( Shortcut: + )
Each time “ Zoom In ” is used, the zoom factor is
increased by about 30%. The maximum possible zoom level is
25600%.
Note
The keyboard shortcut for “ Zoom In ” has been
somewhat controversial because this is a very common operation
and on English keyboards, the Shift key must
be pressed to use it. ( This is not the case for European
keyboards.) If you would like to have a different keyboard
shortcut, you can create a dynamic shortcut for it; see the
help section for User
Interface Preferences for instructions.
Fit Image in Window
(Shortcut:
Shift + Ctrl + J ).
This command zooms the image to be as large as possible, while
still keeping it completely within the window. There will
usually be padding on two sides of the image, but not on all
four sides.
Fit Image to Window
This command zooms the image as large as possible without
requiring any padding to be shown. This means that the image
fits the window perfectly in one dimension, but usually
extends beyond the window borders in the other dimension.
A:B (X%)
With these commands, you can select one of the pre-set zoom
levels. Each of the menu labels gives a ratio, as well as a
percentage value. Please note that each zoom pre-set has its own
keyboard shortcut. The current zoom is marked with a large dot.
Other
This command brings up a dialog which allows you to choose any
zoom level you would like, within the range of 1:256 (0.39%) to
256:1 (25600%).
Tip
When you are working at the pixel level, you can use the
New view command. This
allows you to see what is happening to the image at its normal size
at the same time.
5.3. Dot for Dot 5.5. Shrink Wrap
 Report an error in Bugzilla 
11. “Windows” Menu 11. “ Windows ” Menu Chapter 16. Menus  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. “ Windows ” Menu
This menu allows you to manage GIMP windows dialogs:
The “ Windows ” menu name is not well adapted to the new
single-window mode. Nevertheless, its functions concern multi and single
modes. Its display may vary according presence or absence of images and
docks:
Figure 16.207. Contents of the “ Windows ” Menu Without open images With open images Recently Closed Docks :
this command opens the list of the docks you have closed recently. You
can reopen them by clicking on their name. Please note that isolated
windows are not concerned.
For more information about docks, please see
Dialogs and Docking .
Dockable Dialogs : this command opens the list of
dockable dialogs. Please refer to Section 2.3, “Dialogs and Docking” .
Toolbox : clicking on this command or using the
Ctrl + B shortcut,
raises the toolbox usually together with the tool options dock.
The list of open image windows: clicking on an image name, or using the
Alt + Number of the
image shortcut, makes the image active.
The list of open docks: in this list, docks are named with the
name of the active dialog in this dock. Clicking on a dock name raises
this dock.
Hide Docks ( Tab ): this command hides
all docks (usually to the left and right of the image), leaving the
image window alone. The command status is kept on quitting GIMP; then,
GIMP starts with no dock in multi-window mode, but not in single-window
mode, although the option is checked!
Single Window Mode : when enabled, GIMP is in a
single window mode. Please see Single Window Mode .
10.6. The “ Script-Fu ” Submenu 12. The “ Help ” Menu
 Report an error in Bugzilla  Glossary Glossary  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Glossary Alpha
An Alpha value indicates the transparency of a pixel. Besides its
Red, Green and Blue values , a pixel has an alpha value. The smaller
the alpha value of a pixel, the more visible the colors below it. A
pixel with an alpha value of 0 is completely transparent. A pixel
with an alpha value of 255 is fully opaque.
With some image
file formats , you can only
specify that a pixel is completely transparent or completely opaque .
Other file formats allow a variable level of transparency.
Alpha Channel
An alpha channel of a layer
is a grayscale image of the same size as the layer representing its
transparency. For each pixel the gray level ( a value between 0 and
255 ) represents the pixels's
Alpha value. An alpha channel
can make areas of the layer to appear partially transparent. That's
why the background layer has no alpha channel by default.
The image alpha channel, which is displayed in the channels dialog,
can be considered as the alpha channel of the final layer when all
layers have been merged.
See also Example for Alpha channel .
Antialiasing
Antialiasing is the process of reversing an alias, that is,
reducing the “ jaggies ” . Antialiasing
produces smoother curves by adjusting the boundary between the
background and the pixel region that is being antialiased. Generally,
pixel intensities or opacities are changed so that a smoother
transition to the background is achieved. With selections, the
opacity of the edge of the selection is appropriately reduced.
Bézier curve
A spline is a curve which is defined mathematically and has a set of
control points. A Bézier spline is a cubic spline which has
four control points, where the first and last control points (knots or
anchors) are the endpoints of the curve and the inner two control
points (handles) determine the direction of the curve at the
endpoints.
In the non-mathematical sense, a spline is a flexible strip of wood or
metal used for drawing curves. Using this type of spline for drawing
curves dates back to shipbuilding, where weights were hung on splines
to bend them. The outer control points of a Bézier spline are
similar to the places where the splines are fastened down and the
inner control points are where weights are attached to modify the
curve.
Bézier splines are only one way of mathematically representing
curves. They were developed in the 1960s by Pierre Bézier, who
worked for Renault.
Bézier curves are used in GIMP as component
parts of Paths .
The image above shows a Bézier curve. Points P0 and P3 are
points on the Path, which are created by clicking with the mouse.
Points P1 and P2 are handles, which are automatically created by
GIMP when you stretch the line.
Bitmap
From
The Free Online Dictionary of Computing (13 Mar 01)
:
bitmap — A data file or structure which corresponds bit for
bit with an image displayed on a screen, probably in the same
format as it would be stored in the display's video memory or
maybe as a device independent bitmap. A bitmap is characterised by
the width and height of the image in pixels and the number of bits
per pixel which determines the number of shades of grey or colors
it can represent. A bitmap representing a colored image (a
“ pixmap ” ) will usually have pixels with between one
and eight bits for each of the red, green, and blue components ,
though other color encodings are also used. The green component
sometimes has more bits than the other two to cater for the human
eye's greater discrimination in this component.
BMP
BMP is an uncompressed image
file format
designed by Microsoft and mainly used in Windows. Colors are
typically represented in 1, 4 or 8 bits, although the format also
supports more. Because it is not compressed and the files are large,
it is not very well suited for use in the internet.
Bump mapping
Bump mapping is a technique for displaying extremely detailed objects
without increasing the geometrical complexity of the objects. It is
especially used in 3-dimensional visualization programs. The trick is
to put all the necessary information into a texture, with which
shadowing is shown on the surface of the object.
Bump mapping is only one (very effective) way of simulating surface
irregularities which are not actually contained in the geometry of the
model.
Channel
A channel refers to a certain component of an image. For instance, the
components of an RGB image are the
three primary colors red, green, blue, and sometimes transparency
( alpha).
Every channel is a grayscale image of exactly the same size as the
image and, consequently, consists of the same number of pixels . Every
pixel of this grayscale image can be regarded as a container which can
be filled with a value ranging from 0 to 255. The exact meaning of
this value depends on the type of channel, e.g. in the
RGB color model the value in the
R -channel means the amount of red which is added
to the color of the different pixels; in the selection channel, the
value denotes how strongly the pixels are selected; and in the alpha
channel the values denote how opaque the corresponding pixels are.
See also Channels .
Channel Mask
A channel masks is a special type of mask which determines the
transparency of a selection. See Masks for
a detailed description.
Clipboard
The Clipboard is a temporary area of memory which is used to
transfer data between applications or documents. It is used when you
Cut, Copy or Paste data in GIMP .
The clipboard is implemented slightly differently under different
operating systems. Under Linux/XFree, GIMP uses
the XFree clipboard for text and the GIMP
internal image clipboard for transferring images between image
documents. Under other operating systems, the clipboard may work
somewhat differently. See the GIMP documentation
for your operating system for further information.
The basic operations provided by the clipboard are
“ Cut ” , “ Copy ” , and “ Paste ” .
Cut means that the item is removed from the document and copied to
the clipboard. Copy leaves the item in the document and copies it to
the clipboard. Paste copies the contents of the clipboard to the
document. The GIMP makes an intelligent decision
about what to paste depending upon the target. If the target is a
canvas, the Paste operation uses the image clipboard. If the target
is a text entry box, the paste operation uses the text clipboard.
CMY, CMYK
CMYK is a color model
which has components for Cyan, Magenta, Yellow and Black. It is a
subtractive color model, and that fact is important when an image
is printed. It is complementary to the
RGB color model.
The values of the individual colors vary between 0% and 100%, where 0%
corresponds to an unprinted color, and 100% corresponds to a
completely printed area of color. Colors are formed by mixing the
three basic colors.
The last of these values, K (Black), doesn't contribute to
the color, but merely serves to darken the other colors. The
letter K is used for Black to prevent confusion, since B usually
stands for Blue.
Figure 1116. Subtractive color model GIMP does not currently support the CMYK model.
(An experimental plug-in providing rudimentary CMYK support can be
found [ PLUGIN-SEPARATE ] .)
This is the mode used in printing. These are the colors in the ink
cartridges in your printer. It is the mode used in painting and in all
the objects around us, where light is reflected, not emmitted. Objects
absorb part of the light waves and we see only the reflected part.
Note that the cones in our eyes see this reflected light in RGB mode.
An object appears Red because Green and Blue have been absorbed. Since
the combination of Green and Blue is Cyan, Cyan is absorbed when you
add Red. Conversely, if you add Cyan, its complementary color, Red, is
absorbed. This system is subtractive .
If you add Yellow, you decrease Blue, and if you add Magenta, you
decrease Green.
It would be logical to think that by mixing Cyan, Magenta and Yellow ,
you would subtract Red, Green and Blue, and the eye would see no light
at all, that is, Black. But the question is more complex. In fact, you
would see a dark brown. That is why this mode also has a Black value,
and why your printer has a Black cartridge. It is less expensive that
way. The printer doesn't have to mix the other three colors to create
an imperfect Black, it just has to add Black.
Color depth
Color depth is simply the number of bits used to represent a color
(bits per pixel : bpp). There are 3 channels for a pixel ( for Red,
Green and Blue ). GIMP can support 8 bits per
channel, referred as eight-bit color . So,
GIMP color depth is 8 * 3 = 24,
which allows
256 * 256 * 256 = 16,777,216 possible
colors (8 bits allow 256 colors).
Color model
A color model is a way of describing and specifying a color. The term
is often used loosely to refer to both a color space system and the
color space on which it is based.
A color space is a set of colors which can be displayed or
recognized by an input or output device (such as a scanner, monitor,
printer, etc.). The colors of a color space are specified as values
in a color space system, which is a coordinate system in which the
individual colors are described by coordinate values on various axes.
Because of the structure of the human eye, there are three axes in
color spaces which are intended for human observers. The practical
application of that is that colors are specified with three
components (with a few exceptions). There are about 30 to 40 color
space systems in use. Some important examples are:
RGB HSV CMY(K) YUV YCbCr Dithering
Dithering is a technique used in computer graphics to create the
illusion of more colors when displaying an image which has a low
color depth . In a
dithered image, the missing colors are reproduced by a certain
arrangement of pixels in the available colors. The human eye
perceives this as a mixture of the individual colors.
The Gradient tool uses
dithering. You may also choose to use dithering when you convert an
image to Indexed
format. If you are working on an image with indexed colors, some
tools (such as the pattern fill tool) may also use dithering, if the
correct color is not available in the colormap.
The Newsprint filter
uses dithering as well. You can use the
NL Filter (Non Linear filter)
to remove unwanted dithering noise from your image.
Also note that although GIMP itself uses 24-bit
colors, your system may not actually be able to display that many
colors. If it doesn't, then the software in between
GIMP and your system may also dither colors while
displaying them.
See also the glossary entry on
Floyd-Steinberg
dithering , which is used in GIMP .
EXIF
Exchangeable image file format (official abbreviation Exif, not
EXIF) is a specification for the image file format used by digital
cameras. It was created by the Japan Electronic Industry Development
Association (JEIDA). The specification uses the existing JPEG, TIFF
Rev. 6.0, and RIFF WAVE file formats, with the addition of specific
metadata tags. It is not supported in JPEG 2000 or PNG. Version 2.1 of
the specification is dated June 12, 1998 and version 2.2 is dated
April 2002. The Exif tag structure is taken from that of TIFF files.
There is a large overlap between the tags defined in the TIFF, Exif,
TIFF/EP and DCF standards
[ WKPD-EXIF ] .
Feathering
The process of Feathering makes a smooth transition between a region
and the background by softly blending the edges of the region .
In GIMP , you can feather the edges of a
selection. Brushes can also have feathered edges.
File Format
A file format or file type is the form in which computer data is
stored. Since a file is stored by an operating system as a linear
series of bytes, which cannot describe many kinds of real data in
an obvious way, conventions have been developed for interpreting
the information as representations of complex data. All of the
conventions for a particular “ kind ” of file constitute
a file format.
Some typical file formats for saving images are JPEG, TIFF, PNG and
GIF. The best file format for saving an image depends upon how the
image is intended to be used. For example, if the image is intended
for the internet, file size is a very important factor, and if the
image is intended to be printed, high resolution and quality have
greater significance. See
Format types .
Floating Selection
A floating selection (sometimes called a “ floating
layer ” ) is a type of temporary layer which is similar in
function to a normal layer, except that a floating selection must be
anchored before you can
resume working on any other layers in the image .
In early versions of GIMP , when
GIMP did not use layers, floating selections were
used for performing operations on a limited part of an image (you can
do that more easily now with layers ). Now floating selections have no
practical use, but you must know what you have to do with them.
Floyd-Steinberg Dithering
Floyd-Steinberg dithering is a method of
dithering which was first
published in 1976 by Robert W. Floyd and Louis Steinberg. The
dithering process begins in the upper left corner of the image . For
each pixel, the closest available color in the palette is chosen and
the difference between that color and the original color is computed
in each RGB channel. Then specific fractions of these differences
are dispersed among several adjacent pixels which haven't yet been
visited (below and to the right of the original pixel). Because of
the order of processing, the procedure can be done in a single pass
over the image.
When you convert an image to
Indexed
mode, you can choose between two variants of Floyd-Steinberg
dithering.
Gamma
Gamma or gamma correction is a non-linear operation which is used to
encode and decode luminance or color values in video or still image
systems. It is used in many types of imaging systems to straighten out
a curved signal-to-light or intensity-to-signal response. For example,
the light emitted by a CRT is not linear with regard to its input
voltage, and the voltage from an electric camera is not linear with
regard to the intensity (power) of the light in the scene. Gamma
encoding helps to map the data into a perceptually linear domain, so
that the limited signal range (the limited number of bits in each RGB
signal) is better optimized perceptually.
Gamma is used as an exponent (power) in the correction equation. Gamma
compression (where gamma & lt; 1) is used to encode linear luminance or
RGB values into color signals or digital file values, and gamma
expansion (where gamma & gt; 1) is the decoding process, and usually
occurs where the current-to-voltage function for a CRT is non-linear.
For PC video, images are encoded with a gamma of about 0. 45 and
decoded with a gamma of 2.2. For Mac systems, images are typically
encoded with a gamma of about 0. 55 and decoded with a gamma of 1.8.
The sRGB color space standard used for most cameras, PCs and printers
does not use a simple exponential equation, but has a decoding gamma
value near 2.2 over much of its range.
In GIMP , gamma is an option used in the brush tab
of the GIMPressionist
filter and in the Flame filter.
The display filters
also include a Gamma filter. Also see the
Levels Tool , where you can
use the middle slider to change the gamma value.
Gamut
In color reproduction, including computer graphics and photography,
the gamut, or color gamut (pronounced /ˈgæmət/), is a certain complete
subset of colors. The most common usage refers to the subset of colors
which can be accurately represented in a given circumstance, such as
within a given color space or by a certain output device. Another
sense, less frequently used but not less correct, refers to the
complete set of colors found within an image at a given time. In this
context, digitizing a photograph, converting a digitized image to a
different color space, or outputting it to a given medium using a
certain output device generally alters its gamut, in the sense that
some of the colors in the original are lost in the process.
[ WKPD-GAMUT ]
GIF GIF ™ stands for Graphics
Interchange Format. It is a file
format with good, lossless compression for images with low
color depth
(up to 256 different colors per image). Since GIF was developed, a
new format called
Portable Network Graphics
(PNG) has been developed, which is better than GIF in all
respects, with the exception of animations and some rarely-used
features.
GIF was introduced by CompuServe in 1987. It became popular mostly
because of its efficient, LZW compression. The size of the image files
required clearly less disk space than other usual graphics formats of
the time, such as PCX or MacPaint. Even large images could be
transmitted in a reasonable time, even with slow modems. In addition,
the open licensing policy of CompuServe made it possible for any
programmer to implement the GIF format for his own applications free
of charge, as long as the CompuServe copyright notice was attached to
them.
Colors in GIF are stored in a color table which can hold up to 256
different entries, chosen from 16.7 million different color values.
When the image format was introduced, this was not a much of a
limitation, since only a few people had hardware which could display
more colors than that. For typical drawings, cartoons, black-and-white
photographs and similar uses, 256 colors are quite sufficient as a
rule, even today. For more complex images, such as color photographs,
however, a huge loss of quality is apparent, which is why the format
is not considered to be suitable for those purposes.
One color entry in the palette can be defined to be transparent.
With transparency, the GIF image can look like it is non-rectangular
in shape. However, semi-transparency, as in
PNG , is not possible.
A pixel can only be either entirely visible or completely
transparent.
The first version of GIF was 87a. In 1989, CompuServe published an
expanded version, called 89a. Among other things, this made it
possible to save several images in one GIF file, which is especially
used for simple animation. The version number can be distinguished
from the first six bytes of a GIF file. Interpreted as ASCII symbols,
they are “ GIF87a ” or “ GIF89a ” .
GNU
The GNU project was started in 1983 by Richard Stallman with the
goal of developing a completely free operating system. It is
especially well-known from the GNU General Public License (GPL) and
GNU/Linux, a GNU-variant with a Linux kernel.
The name came about from the naming conventions which were in
practice at MIT, where Stallman worked at the time.
For programs which were similar to other programs, recursive
acronyms were chosen as names. Since the new system was to be based
on the widespread operating system, Unix, Stallman looked for that
kind of name and came up with GNU, which stands for
“ GNU is not Unix ” . In order to avoid confusion, the
name should be pronounced with the “ G ” , not like
“ new ” . There were several reasons for making GNU
Unix-compatible. For one thing, Stallman was convinced that most
companies would refuse a completely new operating system, if the
programs they used wouldn't run on it. In addition, the architecture
of Unix made quick, easy and distributed development possible,
since Unix consists of many small programs that can be developed
independently of each other, for the most part. Also, many parts of
a Unix system were freely available to anyone and could therefore
be directly integrated into GNU, for example, the typesetting
system, TeX, or the X Window System. The missing parts were newly
written from the ground up.
GIMP (GNU Image Manipulation Program) is an
official GNU application
[ WKPD-GNU ] .
Grayscale
Grayscale is a mode for encoding the colors of an image which
contains only black, white and shades of gray.
When you create a new image, you can choose to create it in
Grayscale mode (which you can colorize later, by changing it to RGB
mode). You can also change an existing image to grayscale by using
the Grayscale ,
Desaturate ,
Decompose ,
Channel
Mixer , although not all formats will accept these changes.
Although you can create images in Grayscale mode and convert images
to it, it is not a color model, in the true sense of the word.
As explained in RGB mode , 24-bit
GIMP images can have up to 256 levels of gray. If
you change from Grayscale to RGB mode, your image will have an RGB
structure with three color channels, but of course, it will still be
gray.
Grayscale image files (8-bit) are smaller than RGB files.
Guides
Guides are lines you can temporarily display on an image while you are
working on it . You can display as many guides as you would like, in
either the horizontal or the vertical direction. These lines help you
position a selection or a layer on the image. They do not appear when
the image is printed .
For more information see
Section 2.2, “Guides” .
Histogram
In digital image processing, a histogram is a graph representing the
statistical frequency of the gray values or the color values in an
image. The histogram of an image tells you about the occurrence of
gray values or color values, as well as the contrast range and the
brightness of the image. In a color image, you can create one
histogram with information about all possible colors, or three
histograms for the individual color channels. The latter makes the
most sense, since most procedures are based on grayscale images and
therefore further processing is immediately possible.
HSV
HSV is a color model
which has components for Hue (the color, such as blue or red),
Saturation (how strong the color is) and Value (the brightness).
The RGB mode is very well suited to computer screens, but it doesn't
let us describe what we see in everyday life; a light green, a
pale pink, a dazzling red, etc. The HSV model takes these
characteristics into account. HSV and RGB are not completely
independent of each other. You can see that with the Color Picker
tool ; when you change a color in one of the color models, the other
one also changes . Brave souls can read
Grokking the GIMP , which explains their
interrelationship.
Brief description of the HSV components: Hue
This is the color itself, which results from the combination of
primary colors. All shades (except for the gray levels) are
represented in a chromatic circle : yellow,
blue, and also purple, orange, etc. The chromatic circle (or
“ color wheel ” ) values range between 0° and 360°.
(The term “ color ” is often used instead of
“ Hue ” . The RGB colors are “ primary
colors ” .)
Saturation
This value describes how pale the color is. A completely
unsaturated color is a shade of gray. As the saturation
increases, the color becomes a pastel shade. A completely
saturated color is pure. Saturation values go from 0 to 100 ,
from white to the purest color.
Value
This value describes the luminosity, the luminous intensity. It
is the amount of light emitted by a color. You can see a change
of luminosity when a colored object is moved from being in the
shadow to being in the sun, or when you increase the luminosity
of your screen. Values go from 0 to 100 . Pixel values in the
three channels are also luminosities: “ Value ” in
the HSV color model is the maximum of these elementary values in
the RGB space (scaled to 0-100).
HTML notation
A hex triplet is a way of encoding a color for a computer. The
“ # ” symbol indicates that the numbers which follow it
are encoded in hexadecimal. Each color is specified in two
hexadecimal digits which make up a triplet (three pairs) of
hexadecimal values in the form “ #rrggbb ” , where
“ rr ” represents red, “ gg ” represents green
and “ bb ” represents blue.
Image Hose
An image hose in GIMP is a special type of brush
which consists of several images. For example, you could have a
brush with footprints, which consists of two images, one for the
left footprint and one for the right. While painting with this
brush, a left footprint would appear first, then a right footprint,
then a left one, etc. This type of brush is very powerful.
An image hose is also sometimes called an “ image pipe ”
or “ animated brush ” . An image hose is indicated in the
Brushes dialog by a small red triangle in the lower right corner of
the brush 's symbol.
For information concerning creating an image hose, please see the
Section 8, “The GIH Dialog Box” and
Section 7, “Adding New Brushes” .
Incremental, paint mode
Incremental mode is a paint mode where each brush stroke is drawn
directly on the active layer. When it is set, each additional stroke
of the brush increases the effect of the brush, up to the maximum
opacity for the brush.
If incremental mode is not set, brush strokes are drawn on a canvas
buffer, which is then combined with the active layer. The maximum
effect of a brush is then determined by the opacity, and stroking with
the brush repeatedly does not increase the effect beyond this limit.
The two images above were created using a brush with spacing set to
60 percent. The image on the left shows non-incremental painting and
the image on the right shows the difference with incremental painting.
Incremental mode is a tool option that is shared by several brush
tools, except those which have a “ rate ” control, which
automatically implies an incremental effect. You can set it by
checking the Incremental checkbox in the
tool option dialog for the tool (Paintbrush, Pencil and Eraser).
Indexed Colors
Indexed color mode is a mode for encoding colors in an image where
each pixel in the image is assigned an 8-bit color number. The color
which corresponds to this number is then put in a table (the palette).
Changing a color in the palette changes all the pixels which refer
to this palette color. Although you can create images in
Indexed Color mode and can transform images to
it, it is , strictly speaking, not a
color model .
See also the Indexed
Palette section and the
Convert Image to Indexed
Colors command.
Interpolation
Interpolation means calculating intermediate values. When you
enlarge ( “ digitally zoom ” ) or otherwise transform
(rotate, shear or give perspective to) a digital image,
interpolation procedures are used to compute the colors of the
pixels in the transformed image. GIMP offers
three interpolation methods, which differ in quality and speed. In
general, the better the quality, the more time the interpolation
takes (see
Interpolation
methods ).
GIMP uses interpolation when you
Scale an image,
Scale a layer, and when you
Transform an image.
JPEG
JPEG is a file format
which supports compression and works at all color depths. The
image compression is adjustable, but beware: Too high a compression
could severely reduce image quality, since JPEG compression is lossy.
Use JPEG to create web graphics or if you don't want your
image to take up a lot of space. JPEG is a good format for
photographs and for computer-generated images (CGI). It is not well
suited for:
digital line drawings (for example, screenshots or vector
graphics), in which there are many neighboring pixels with the
same color values, few colors and hard edges,
Black and white images (only black and white, one bit per pixel)
or
half-toned images (newsprint).
Other formats, such as GIF, PNG or JBIG, are far better for these
kinds of images.
In general, JPEG transformations are not reversible. Opening and
then saving a JPEG file causes a new, lossy compression. Increasing
the quality factor later will not bring back the image information
which was lost.
L*a*b*
The Lab color space (also called the L*a*b* color space) is a
color model
developed in the beginning of the 1930s by the Commission
Internationale d`Eclairage (CIE). It includes all the colors that
the human eye can perceive. That contains the colors of the
RGB and the CMYK color spaces, among others. In Lab, a color is
indicated by three values: L, a and b. Here, the L stands for the
luminance component — corresponding to the gray value — and a and b
represent the red-green and blue-yellow parts of the color,
respectively.
In contrast to RGB or CMYK, Lab is not dependent upon the
various input and output devices. For that reason, it is used as an
exchange format between devices. Lab is also the internal color
model of PostScript Level II.
Layer
You can think of layers as being a stack of slides which are more or
less transparent. Each layer represents an aspect of the image and
the image is the sum of all of these aspects. The layer at the bottom
of the stack is the background layer. The layers above it are the
components of the foreground.
You can view and manage the layers of the image through the
Layers dialog .
Figure 1117. Example image with layers Representation of an image with layers The final image Marching Ants
Marching ants is a term which describes the dotted line which
surrounds a selection. The line is animated, so it looks as if
little ants are running around behind each other.
Masks
A mask is like a veil put over a layer (layer mask) or all the layers
of an image (selection mask). You can remove this mask by painting
with white color, and you can complete it by painting with black
color. When the mask is “ applied ” , non masked pixels
will remain visible (the others will be transparent) or will be
selected, according to the type of mask.
There are two types of masks: Layer Mask :
Every layer can have its own mask. The layer mask represents the
Alpha channel of the layer and allows you to manage its
transparency. By painting on the layer mask, you can make parts of
the layer opaque or transparent: painting with black makes the
layer transparent, painting with white makes the layer opaque and
painting with shades of gray makes the layer semi-transparent. You
can use all paint tools to paint on the mask. You can also apply a
filter or copy-paste. You can use the Layer mask for transition
effects, volume effects, merging elements from another image, etc.
See the Layer Mask
section for more details.
Channel Mask , also called
Selection Mask :
Channel Masks determine the transparency of a selection. By
painting on a Channel Mask with white, you remove the mask and
increase the selection; with black, you reduce the selection.
This procedure lets you create a selection very precisely. You
can also save your selections to a Channel Mask with the
Save to Channel
command . You can retrieve it later by using the
“ Channel to selection ” command from the
Channel menu . Channel
masks are so important in GIMP that a
special type has been implemented: the
Quick mask . See the
Selection mask
section for more details.
Moiré Effect
The moiré effect (pronounce “ Moa-ray ” ) is an
unintended pattern which appears when a regular pattern of grids or
lines interferes with another regular pattern placed over it. This can
happen, for example, when you are scanning an image with a periodic
structure (such as a checkered shirt or a half-toned image), scanning
a digital image, taking a digital photograph of a periodic pattern,
or even when silkscreening.
If you discover the problem in time, the best solution is to move
the original image a little bit in the scanner or to change the
camera angle slightly.
If you cannot re-create the image file, GIMP
offers some filters which may help you with the problem. For more
information, see the
Despeckle and
NL Filter (Non-Linear)
filters.
Parasite
A Parasite is additional data which may be written to an XCF file. A
parasite is identified by a name, and can be thought of as an
extension to the other information in an XCF file.
Parasites of an image component may be read by
GIMP
plug-ins. Plug-ins may also define their own parasite names, which are
ignored by other plug-ins. Examples of parasites are comments, the
save options for the TIFF, JPEG and PNG file formats, the gamma value
the image was created with and EXIF data.
Path
A Path is a contour composed of straight lines, curves, or both. In
GIMP , it is used to form the boundary of a
selection, or to be stroked to create visible
marks on an image. Unless a path is stroked, it is not visible when
the image is printed and it is not saved when the image is written
to a file (unless you use XCF format).
See the Paths Concepts
and Using Paths sections for
basic information on paths, and the
Path Tool section for
information on how to create and edit paths. You can manage the
paths in your image with the
Paths dialog .
PDB
All of the functions which GIMP and its
extensions make available are registered in the Procedure Database
(PDB). Developers can look up useful programming information about
these functions in the PDB by using the
Procedure Browser .
PDF
PDF (Portable Document Format) is a
file format which was
developed by Adobe to address some of the deficiencies of
PostScript. Most importantly, PDF files tend to be much smaller than
equivalent PostScript files. As with PostScript,
GIMP 's support of the PDF format is through the
free Ghostscript libraries.
Pixel
A pixel is a single dot, or “ picture element ” , of an
image. A rectangular image may be composed of thousands of pixels,
each representing the color of the image at a given location. The
value of a pixel typically consists of several
Channels , such as the Red,
Green and Blue components of its color, and sometimes its Alpha
(transparency).
Plugin
Optional extensions for the GIMP . Plugins are
external programs that run under the control of the main GIMP
application and provide specific functions on-demand. See
Section 1, “Plugins” for further information.
PNG
PNG is the acronym of “ Portable Network Graphic ”
(pronounce “ ping ” . This recent format offers many
advantages and a few drawbacks: it is not lossy and gives files
more heavy than the JPEG format, but it is perfect for saving your
images because you can save them several times without losing
data each time (it is used for this Help). It supports True Colors
(several millions of colors), indexed images (256 colors like GIF),
and 256 transparency levels (while GIF supports only two levels).
PostScript
Created by Adobe, PostScript is a page description language mainly
used by printers and other output devices. It's also an excellent way
to distribute documents. GIMP does not support
PostScript directly: it depends on a powerful free software program
called Ghostscript .
The great power of PostScript is its ability to represent vector
graphics—lines, curves, text, paths, etc.—in a resolution-independent
way. PostScript is not very efficient, though, when it comes to
representing pixel-based raster graphics. For this reason, PostScript
is not a good format to use for saving images that are later going to
be edited using GIMP or another graphics program.
PSD
PSD is Adobe Photoshop's native
file format , and it is
therefore comparable to XCF
in complexity. GIMP 's ability to handle PSD files
is sophisticated but limited: some
features of PSD files are not loaded, and only older versions of PSD
are supported. Unfortunately, Adobe has now made the Photoshop
Software Development Kit — which includes their file format
specifications — proprietary, and only available to a limited set of
developers approved by Adobe. This does not include the
GIMP
development team, and the lack of information makes it very difficult
to maintain up-to-date support for PSD files.
Quantization
Quantization is the process of reducing the color of a pixel into one
of a number of fixed values by matching the color to the nearest color
in the colormap. Actual pixel values may have far more precision than
the discrete levels which can be displayed by a digital display. If
the display range is too small, then abrupt changes in colors (false
contours, or banding) may appear where the color intensity changes
from one level to another. This is especially noticeable in Indexed
images, which have 256 or fewer discrete colors.
One way to reduce quantization effects is to use
Dithering . The
operations in GIMP which perform
dithering are the
Blend tool
(if you have enabled the dithering option) and the
Convert to Indexed
command. However, they only work on RGB images and not on Indexed
images.
Rendering Intent
Rendering intents are ways of dealing with colors that are
out-of- Gamut colors present in the source
space that the destination space is incapable of producing. There are
four rendering intents defined by the ICC:
Perceptual
This rendering intent is typically used for photographic
content. It scales one gamut to fit into the other while
maintaining the relative position of colors.
Relative colorimetric
This rendering intent is typically used for spot colors. Colors
that are not out of gamut are left unchanged. Colors outside the
gamut are converted to colors with the same lightness, but
different saturation, at the edge of the gamut.
Saturation
This method is typically used for business graphics. The
relative saturation of colors is mostly maintained, but
lightning is usually changed.
Absolute colorimetric
This rendering intent is most often used in proofing. It
preserves the native device white point of the source image.
RGB Figure 1118.
Additive color model
RGB is a color model
which has components for Red, Green and Blue . These colors are
emitted by screen elements and not reflected as they are with paint.
The resulting color is a combination of the three primary RGB colors,
with different degrees of lightness. If you look closely at your
television screen, whose pitch is less than that of a computer
screen, you can see the red, green and blue elements lit with
different intensities. The RGB color model is
additive .
GIMP uses eight bits per channel for each primary
color. That means there are 256 intensities (Values) available,
resulting in 256×256×256 = 16,777,216 colors.
It is not obvious why a given combination of primary colors produces a
particular color. Why, for instance, does 229R+205G+229B give a shade
of pink? This depends upon the human eye and brain. There is no color
in nature, only a continuous spectrum of wavelengths of light. There
are three kinds of cones in the retina. The same wavelength of light
acting upon the three types of cones stimulates each of them
differently, and the mind has learned, after several million years of
evolution, how to recognize a color from these differences.
It is easy to see that no light (0R+0G+0B) produces complete darkness,
black, and that full light (255R+255G+255B) produces white. Equal
intensity on all color channels produces a level of gray. That is why
there can only be 256 gray levels in GIMP .
Mixing two Primary colors in RGB mode
gives a Secondary color , that is, a
color in the CMY model. Thus combining Red and Green gives
Yellow, Green and Blue give Cyan, Blue and Red give Magenta.
Don't confuse secondary colors with
Complementary colors which are
directly opposite a primary color in the chromatic
circle:
Figure 1119. Colorcircle
Mixing a primary color with its complementary color gives gray
(a neutral color).
It is important to know what happens when you are dealing with colors
in GIMP .
The most important rule to remember is that decreasing the intensity
of a primary color results in increasing the intensity of the
complementary color (and vice versa). This is because when you
decrease the value of a channel, for instance Green, you automatically
increase the relative importance of the other two, here Red and Blue.
The combination of these two channels gives the secondary color,
Magenta, which is the complementary color of Green.
The Color Picker
tool lets you find out the RGB values of a pixel and the
hextriplet
for the color.
Sample Merge
Sample Merged is an option you can set when you use the
Bucket Fill
tool , the Color Picker
tool and various selection tools. It is useful when you are working on
an image with several layers and the active layer is either
semi-transparent or has a
Layer Mode
which is not set to Normal. When you check the Sample Merged option,
the color which is used for the operation is the composite color of
all the visible layers. When the Sample Merged option is not checked,
the color used is the color of the active layer itself.
Saturation
This term refers to color purity. Imagine you add pigment to white
paint. Saturation varies from 0 (white, fully toned down, fully
diluted) to 100 (pure color).
Supersampling
Supersampling is a more sophisticated antialiasing technique, that
is, a method of reducing jagged and stair-stepped edges along a
slanted or curved line. Samples are taken at several locations
within each pixel, not just at the center, and
an average color is calculated. This is done by rendering the image
at a much higher resolution than the one being displayed and then
shrinking it to the desired size, using the extra pixels for
calculation. The result is a smoother transition from one line of
pixels to another along the edges of objects.
The quality of the result depends on the number of samples.
Supersampling is often performed at a range of 2× to 16× the original
size. It greatly increases the amount of time needed to draw the image
and also the amount of space needed to store the image in memory.
One way to reduce the space and time requirement is to use Adaptive
Supersampling. This method takes advantage of the fact that very few
pixels are actually on an object boundary, so only those pixels need to
be supersampled. At first, only a few samples are taken within a pixel.
If the colors are very similar to each other, only those samples are
used to calculate the final color. If not, more samples are used. This
means that the higher number of samples is calculated only where
necessary, which improves performance.
SVG
SVG stands for Scalable Vector Graphics. It is a format for
two-dimensional vector graphics, both static and animated. You can
export GIMP paths to SVG and you can import SVG documents into GIMP
from a vector graphic software. See
[ WKPD-SVG ] for more details.
TGA
TGA (TARGA Image File) is a
file format which
supports 8, 16, 24 or 32 bits per pixel and optional RLE compression.
It was originally developed by the Truevision company.
“ TGA ” stands for Truevision Graphics Adapter and
“ TARGA ” stands for Truevision Advanced Raster Graphics
Adapter.
TIFF
TIFF (Tagged Image File Format) is a
file format which was
developed primarily for scanned
raster graphics for color separation. Six different encoding routines
are supported, each with one of three different image modes: black and
white, grayscale and color. Uncompressed TIFF images may be 1, 4, 8 or
24 bits per pixel. TIFF images compressed using the LZW algorithm may
be 6, 8 or 24 bits per pixel. Besides Postscript format, TIFF is one
of the most important formats for preliminary stages of printing. It
is a high quality file format, which is perfect for images you want to
import to other programs like FrameMaker or CorelDRAW.
Tile
A Tile is a part of an image which GIMP
currently has open. In order to avoid having to store an
entire image in memory at the same time,
GIMP divides it into smaller pieces.
A tile is usually a square of 64 x 64 pixels, although tiles at
the edges of an image may be smaller than that.
At any time, a tile may be in main memory, in the tile cache
in RAM , or on disk. Tiles which are currently being worked on are
in main memory. Tiles which have been used recently are in RAM.
When the tile cache in RAM is full, tiles which have been used
least recently are written to disk. GIMP
can retrieve the tiles from RAM or disk when they are needed.
Do not confuse these tiles with those in the
Tile Filter
URI
A Uniform Resource Identifier (URI) is a string of characters that
serves to identify an abstract or a physical resource. URIs are used
for the identification of resources in the Internet (such as web
pages, miscellaneous files, calling up web services, and for receivers
of e-mail) and they are especially used in the Worldwide Web.
URL
URLs (Uniform Resource Locators) are one type of Uniform Resource
Identifiers (URIs). URLs identify a resource by its primary access
mechanism (commonly http or ftp) and the location of the resource in
the computer network. The name of the URI scheme is therefore
generally derived from the network protocol used for it. Examples of
network protocols are http, ftp and mailto.
Since URLs are the first and most common kinds of URIs, the terms are
often used synonymously.
Value
This term often refers to the light intensity, the luminosity of
a color. It varies from 0 (black) to 100 (full light).
XCF
XCF is a file format
which is special because it is GIMP 's
native file format: that is, it was designed specifically to store all
of the data that goes to make up a GIMP image.
Because of this, XCF files may be quite complicated, and there are
few programs other than GIMP that can read them.
When an image is stored as an XCF file, the file encodes nearly
everything there is to know about the image: the pixel data for each
of the layers, the current selection, additional channels if there are
any, paths if there are any, and guides. The most important thing that
is not saved in an XCF file is the undo history.
The pixel data in an XCF file is represented
in a lossless compressed form: the image byte blocks are compressed
using the lossless RLE algorithm. This means that no matter how many
times you load and save an image using this format, not a single
pixel or other image data is lost or modified because of this format.
XCF files can become very large, however GIMP
allows you to compress the files themselves, using either the gzip
or bzip2 compression methods, both of which are fast, efficient, and
freely available. Compressing an XCF file will often shrink it by a
factor of 10 or more.
The GIMP developers have made a great effort to
keep the XCF file format compatible across versions. If you create a
file using GIMP 2.0, it ought to be possible to
open the file in GIMP 1.2. However, some of the
information in the file may not be usable: for example,
GIMP 2.0 has a much more sophisticated way of
handling text than GIMP 1.2, so a text layer
from a GIMP 2.0 XCF file will appear as an
ordinary image layer if the file is opened in
GIMP 1.2.
YCbCr
YCbCr is a color model
which was developed for the PAL television standard as a simple
modification to the YUV color model. In the
meantime, it has become the CCIR-601 standard for image and video
recording. For example, it is used for JPEG pictures and MPEG videos,
and therefore also on DVDs, video CDs and for most other widespread
digital video standards. Note that a color model is still not a color
space, since it doesn't determine which colors are actually meant by
“ red ” , “ green ” and “ blue ” .
For a color space, there must still be a reference to a specific
absolute color value.
There are color models which do not express a color by the additive
basic colors, red, green and blue (RGB), but by other properties, for
example, the brightness-color model. Here, the criteria are the basic
brightness of the colors (from black, through gray, to white), the
colors with the largest portion (red, orange, yellow, green, blue,
violet, or other pure colors that lie between them) and the saturation
of the colors ( “ gaudy ” to pale). This color model is
based on the
ability of the eye to recognize small differences in luminosity
better than small color differences, and to recognize those better
than small differences in saturation. That makes gray text written on
a black background easy to read, but blue text on a red background
very hard to read, even with the same basic brightness. Such color
models are called brightness-color models.
The YCbCr model is a slight adaptation of such a brightness-color
model. An RGB color value is divided into a basic brightness, Y, and
two components, Cb and Cr, where Cb is a measurement of the deviation
from gray in the blue direction, or if it is less than 0.5, in the
direction of yellow. Cr is the corresponding measurement for the
difference in the direction of red or turquoise. This representation
uses the peculiarity of the eye of being especially sensitive to green
light. That is why most of the information about the proportion of
green is in the basic brightness, Y, an only the deviations for the
red and blue portions need to be represented. The Y values have twice
the resolution of the other two values, Cb and Cr, in most practical
applications, such as on DVDs.
YUV
YUV is a color model
which uses two components to represent the color
information, luma (the strength of the light per area) and the
chrominance, or proportion of color (chroma), where the chrominance
again consists of two components. The development of the YUV color
model also goes back to the development of color television (PAL),
where ways were sought for transmitting the color information
along with the black-and-white signal , in order to achieve backwards
compatibility with old black and white televisions without having to
increase the available transmission bandwidth. From the YUV color
model of the analog television techiques, the YCrCb color model was
developed, which is used for most kinds of digital image and video
compression. Erroneously, the YUV color model is also often spoken
about in those fields, although the YCbCr model is actually used.
This often causes confusion.
For the calculation of the luma signals, the underlying RGB data is
first adjusted with the gamma
value of the output device, and an R'G'B' signal is obtained. The
three individual components are added together with different
weights, to form the brightness information, which also functions as
the VBS signal (Video Baseband Signal, the black-and-white signal )
for the old black and white televisions .
Y=R+G+B
The exact calculation is more complicated, however, since some aspects
of the color perception of the human eye have to be taken into
account. For example, green is perceived to be lighter than red, and
this is perceived to be lighter than blue. Furthermore, in some
systems gamma correction of the basic color is first performed.
The chrominance signals, and the color difference signals also,
contain the color information. They are formed by the difference of
blue minus luma or red minus luma.
U=B-Y V=R-Y
From the three generated components, Y, U and V, the individual
color proportions of the basic color can be calculated again later:
Y + U = Y + ( B - Y ) = Y - Y + B = B Y + V = Y + ( R - Y ) = Y - Y + R = R Y - B - R = ( R + G + B ) - B - R = G
Furthermore, because of the structure of the retina of the human
eye, it turns out that the brightness information is perceived at a
higher resolution than the color, so that many formats based on
the YUV color model compress the chrominance to save bandwidth
during transmission.
Zoom tool Bibliography
 Report an error in Bugzilla 
Appendix D. Eeek! There is Missing Help Appendix D. Eeek! There is Missing Help  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Appendix D. Eeek! There is Missing Help
Sorry, but a help item is missing for the function you're looking for.
You may be able to find it in the online version of the help at the
GIMP docs
website.
Feel free to join us and fill the gap by writing documentation for
GIMP . For more information, subscribe to our
Mailing
list . Generally, it's a good idea to check the
GIMP project
page .
Found a content error or just
something which doesn't look right?
 Report an error in Bugzilla  and let us know.
12. ADDENDUM: How to use this License for your documents Index
 Report an error in Bugzilla  2. 6. Image-Dependent Scripts 2.6. Image-Dependent Scripts 2. Using Script-Fu Scripts  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 6. Image-Dependent Scripts
Now, scripts and filters that perform operations on an existing image are
accessible directly by the appropriate menu. For example, the script
New Brush (script-fu-paste-as-brush)
is integrated in the Edit image menu
( Edit → Paste as... → New Brush ),
that is more logical.
Furthermore, a new Color menu has been created that
regroups together all that concern works on colors, the hue or level color
adjustment tools, etc...
Filters menu and Scripts-Fu menu are
regrouped in one Filters menu and organised according
to new categories. Now if a plugin and a filter works similarly, they are
nearby in the menu.
The Scripts-Fu menu only appears if you have loaded
additional scripts: for example the gimp-resynthesizer pack corresponding
to your Linux distribution ( .deb ,
.rpm ,
.gz ...).
2.5. Standalone Scripts 3. A Script-Fu Tutorial  Report an error in Bugzilla  2. 2. Installing Script-Fus 2. 2. Installing Script-Fus 2. Using Script-Fu Scripts  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Installing Script-Fus
One of the great things about Script-Fu is that you can share your
script with all your GIMP friends. There are many
scripts that come with GIMP by default, but
there are also vast quantities of scripts that are
available for download all around the Internet.
If you have downloaded a script, copy or move it to your
scripts directory. It can be found in the
Preferences :
Folders → Scripts .
Do a refresh by using
Filters → Script-Fu → Refresh Scripts
from the image menubar.
The script will now appear in one of your menus.
If you don't find it, look for it under the root file menu
filters. If it doesn't appear at all, something was wrong with
the script (e.g. it contains syntax errors).
2. Using Script-Fu Scripts 2. 3. Do's and Don'ts  Report an error in Bugzilla 
Chapter 1. Introduction Chapter 1. Introduction Part I. Getting Started  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 1. Introduction Table of Contents 1. Welcome to GIMP 1.1. Authors 1.2. The GIMP Help system 1.3. Features and Capabilities 2. What's New in GIMP 2.8? 1. Welcome to GIMP GIMP is a multi-platform photo
manipulation tool. GIMP is an acronym for
GNU Image Manipulation Program. The
GIMP is suitable for a variety of image
manipulation tasks, including photo retouching, image composition, and
image construction.
GIMP has many capabilities. It can be used as a
simple paint program, an
expert quality photo retouching program, an online batch processing
system, a mass production image renderer, an image format converter, etc.
GIMP is expandable and extensible. It is designed
to be augmented with
plug-ins and extensions to do just about anything. The advanced scripting
interface allows everything from the simplest task to the most complex
image manipulation procedures to be easily scripted.
One of The GIMP 's strengths is its free
availability from many sources for many operating systems. Most
GNU / Linux distributions
include The GIMP as a standard application.
The GIMP is also available for other
operating systems such as Microsoft Windows ™
or Apple's Mac OS X ™
( Darwin ). The GIMP
is a Free Software application covered by the General Public License
[ GPL ] . The GPL
provides users with the freedom to access and alter the source code that
makes up computer programs.
1.1. Authors
The first version of the GIMP
was written by Peter Mattis and Spencer Kimball . Many other developers
have contributed more recently, and thousands have provided support and
testing. GIMP
releases are currently being orchestrated by Sven Neumann and Mitch
Natterer and the other members of the
GIMP -Team.
1.2. The GIMP Help system
The GIMP Documentation Team and other
users have provided you with the information necessary to understand
how to use GIMP . The User Manual is
an important part of this help. The current version is on
the web site of the Documentation Team
[ GIMP-DOCS ] in HTML format. The HTML
version is also available as context sensitive help (if you installed
it) while using GIMP by pressing the
F1 key . Help on specific menu items can be accessed
by pressing the F1 key while the mouse pointer is
focused on the menu item. Read on to begin your
GIMP journey.
1.3. Features and Capabilities
The following list is a short overview of some of the features and
capabilities which GIMP offers you:
A full suite of painting tools including brushes, a pencil, an
airbrush, cloning, etc.
Tile-based memory management, so image size is limited only by
available disk space
Sub-pixel sampling for all paint tools for high-quality
anti-aliasing
Full Alpha channel support for working with transparency
Layers and channels
A procedural database for calling internal GIMP
functions from external programs, such as Script-Fu
Advanced scripting capabilities Multiple undo/redo (limited only by disk space)
Transformation tools including rotate, scale, shear and flip
Support for a wide range of file formats, including GIF, JPEG, PNG,
XPM, TIFF, TGA, MPEG, PS, PDF, PCX, BMP and many others
Selection tools, including rectangle, ellipse, free, fuzzy, bezier
and intelligent scissors
Plug-ins that allow for the easy addition of new file formats and
new effect filters.
Part I. Getting Started 2. What's New in GIMP 2.8?  Report an error in Bugzilla 
Dialogs Dialogs Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Dialogs —
Key reference for Dockable Dialogs submenu
Dockable Dialogs Ctrl + L Layers Shift +
Ctrl + B
Brushes Shift +
Ctrl + P
Patterns Ctrl + G Gradients Note
These open a new dialog window if it isn't open yet,
otherwise the corresponding dialog gets focus.
Within a Dialog Alt + F4,
Ctrl + W
Close the window Tab Jump to next widget Shift + Tab
Jump to previous widget Enter Set the new value Space,
Enter
Activate current button or list Ctrl +
Alt + PgUp
Ctrl +
Alt + PgDn
In a multi-tab dialog, switch tabs Note
This accepts the new value you typed in a text field and
returns focus to canvas.
Within a File Dialog Shift + L Open Location Alt + Up
Up-Folder Alt + Down Down-Folder Alt + Home Home-Folder Esc Close Dialog File View
 Report an error in Bugzilla  Edit Edit Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Edit —
Key reference for Edit menu
Edit Undo/redo Ctrl + Z Undo Ctrl + Y Redo Clipboard Ctrl + C Copy selection Ctrl + X Cut selection Ctrl + V Paste clipboard Del Erase selection Shift +
Ctrl + C
Named copy selection Shift +
Ctrl + X
Named cut selection Shift +
Ctrl + V
Named paste clipboard Note This puts a copy of the selection on the GIMP clipboard. Fill Ctrl + , Fill with FG Color Ctrl + . Fill with BG Color Ctrl + ; Fill with Pattern View Layer
 Report an error in Bugzilla  File File Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name File —
Key reference for the File menu
File Ctrl + N New image Ctrl + O Open image Ctrl +
Alt + O
Open image as new layer Ctrl + D Duplicate Ctrl + 1 Open recent image #1 Ctrl + 2 Open recent image #2 Ctrl + 3 Open recent image #3 Ctrl + 4 Open recent image #4 Ctrl + 5 Open recent image #5 Ctrl + 6 Open recent image #6 Ctrl + 7 Open recent image #7 Ctrl + 8 Open recent image #8 Ctrl + 9 Open recent image #9 Ctrl + 0 Open recent image #10 Ctrl + S Save image Shift +
Ctrl + S
Save under a new name Ctrl + Q Quit Tools Dialogs
 Report an error in Bugzilla  Filters Filters Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Filters —
Key reference for Filters menu
Filters Ctrl + F Repeat last filter Shift +
Ctrl + F
Reshow last filter Select Zoom tool
 Report an error in Bugzilla  Help Help Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Help —
Key reference for Help menu
Help F1 Help Shift + F1 Context Help Keys and Mouse Reference Tools
 Report an error in Bugzilla  Layer Layer Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Layer —
Key reference for Layer menu
Layers PgUp, Ctrl + Tab Select the layer above
PgDn,
Shift +
Ctrl + Tab
Select the layer below Home Select the first layer End Select the last layer Ctrl + M Merge visible layers Ctrl + H Anchor layer Edit Select
 Report an error in Bugzilla  Select Select Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Select —
Key reference for Select menu
Selections Ctrl + T Toggle selections Ctrl + A Select all Shift +
Ctrl + A
Select none Ctrl + I Invert selection Shift +
Ctrl + L
Float selection Shift + V Path to selection Layer Filters
 Report an error in Bugzilla  Tools Tools Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Tools —
Key reference for the Tools menu
Tools Tools R Rect Select E Ellipse Select F Free Select Z Fuzzy Select Shift + O Select By Color I Scissors B Paths O Color Picker M Move Shift + C Crop and Resize Shift + R Rotate Shift + T Scale Shift + S Shear Shift + P Perspective Shift + F Flip T Text Shift + B Bucket Fill L Blend N Pencil P Paintbrush Shift + E Eraser A Airbrush K Ink C Clone Shift + U Blur/Sharpen S Smudge Shift + D Dodge/Burn Note
Click on a tool icon to open its Tool Options dialog.
Context X Swap Colors D Default Colors Note Click on the colors to change the colors. Help File
 Report an error in Bugzilla  View View Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name View —
Key reference for View menu
View Window F10 Main Menu Shift + F10, right click
Drop-down Menu F11 Toggle fullscreen Shift + Q Toggle quickmask Ctrl + W Close document window Note
Menus can also be activated by Alt with the letter
underscored in the menu name.
Zoom + Zoom in - Zoom out 1 Zoom 1:1 Ctrl + E Shrink wrap Note This fits the window to the image size. Rulers and Guides mouse drag Drag off a ruler to create guide Ctrl + mouse drag Drag a sample point out of the rulers Shift +
Ctrl + R
Toggle rulers Shift +
Ctrl + T
Toggle guides Note
Drag off the horizontal or vertical ruler to create a new
guideline. Drag a guideline off the image to delete it .
Dialogs Edit
 Report an error in Bugzilla 
Zoom tool Zoom tool Keys and Mouse Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Name Zoom tool —
Key reference for the Zoom tool submenu
Zoom tool click Zoom in Ctrl + click Zoom out mouse drag Zoom into the area Filters Glossary
 Report an error in Bugzilla 
Keys and Mouse Reference Keys and Mouse Reference Part III. Function Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Keys and Mouse Reference Table of Contents Help —
Key reference for Help menu
Tools —
Key reference for the Tools menu
File —
Key reference for the File menu
Dialogs —
Key reference for Dockable Dialogs submenu
View —
Key reference for View menu
Edit —
Key reference for Edit menu
Layer —
Key reference for Layer menu
Select —
Key reference for Select menu
Filters —
Key reference for Filters menu
Zoom tool —
Key reference for the Zoom tool submenu
16.19. Textured Help
 Report an error in Bugzilla  2. 4. Different Kinds Of Script-Fus 2. 4. Different Kinds Of Script-Fus 2. Using Script-Fu Scripts  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 4. Different Kinds Of Script-Fus There are two kinds of Script-Fus:
Standalone Script-Fus
You will find the standalone variants under
File → Create → Type of Script
in the image menubar (see the figure below).
Figure 13.1. Script-Fus by category Image-dependent Script-Fus
Menus have been reorganized. A new Colors-menu appears. It groups
together all scripts that work on colors, for example tools that
adjust hue, saturation, lightness..., filters...etc. Filters-menu
and Script-Fu-menu are merged in one Filters-menu and it is
organized according to new categories. Image-dependent Plug-ins and
Script-Fus are now disseminated in the image-menus. For example,
Color to Alpha filter is in Colors-menu. At the beginning, it's
disconcerting, but you finish to get used to this because it's more
logical.
The figure below show where you can find them in the image-menu.
Figure 13.2. Where find Image-dependent scripts 2.3. Do's and Don'ts 2.5. Standalone Scripts
 Report an error in Bugzilla  Appendix C. GNU Free Documentation License Appendix C. GNU Free Documentation License  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Appendix C. GNU Free Documentation License Version 1.2 , November 2002 Table of Contents 1. PREAMBLE 2. APPLICABILITY AND DEFINITIONS 3. VERBATIM COPYING 4. COPYING IN QUANTITY 5. MODIFICATIONS 6. COMBINING DOCUMENTS 7. COLLECTIONS OF DOCUMENTS 8. AGGREGATION WITH INDEPENDENT WORKS 9. TRANSLATION 10. TERMINATION 11. FUTURE REVISIONS OF THIS LICENSE 12. ADDENDUM: How to use this License for your documents
Note that any translations of the GNU Free Documentation License are not
published by the Free Software Foundation , and do not legally state the
distribution terms for software that uses the GNU FDL-only the
original English text of the GNU FDL does that.
The GIMP Documentation Team
Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA. Everyone is permitted to
copy and distribute verbatim copies of this license document, but
changing it is not allowed.
1. PREAMBLE
The purpose of this License is to make a manual, textbook, or other
functional and useful document “ free ”
in the sense of freedom: to assure everyone the effective freedom to
copy and redistribute it, with or without modifying it, either
commercially or noncommercially. Secondarily, this License preserves for
the author and publisher a way to get credit for their work, while not
being considered responsible for modifications made by others.
This License is a kind of “ copyleft ” ,
which means that derivative works of the document must themselves be
free in the same sense. It complements the GNU General Public License ,
which is a copyleft license designed for free software.
We have designed this License in order to use it for manuals for free
software, because free software needs free documentation: a free program
should come with manuals providing the same freedoms that the software
does. But this License is not limited to software manuals; it can be
used for any textual work, regardless of subject matter or whether it is
published as a printed book. We recommend this License principally for
works whose purpose is instruction or reference.
3. What Happens to a Bug Report after you Submit it 2. APPLICABILITY AND DEFINITIONS
 Report an error in Bugzilla 
Chapter 16. Menus Chapter 16. Menus Part III. Function Reference  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Chapter 16. Menus Table of Contents 1. Introduction to Menus 1.1. The Image Menu Bar 1.2. Context Menus 1.3. Tear-off menus 1.4. Tab menus 2. The “ File ” Menu 2.1. Overview 2.2. New 2.3. Create 2.4. Open 2.5. Open as Layers 2. 6. Open Location 2.7. Open Recent 2. 8. Save 2.9. Save as 2.10. Save a Copy 2.11. Revert 2.12. Export 2.13. Export As... 2.14. Create Template 2.15. Print 2.16. Close 2.17. Close all 2.18. Quit 3. The “ Edit ” Menu 3.1. “ Edit ” Menu Entries 3.2. Undo 3.3. Redo 3.4. Fade 3.5. Undo History 3. 6. Cut 3.7. Copy 3.8. Copy Visible 3.9. Paste 3.10. Paste Into 3.11. Paste as 3.12. Buffer 3.13. Clear 3.14. Fill with FG Color 3.15. Fill with BG Color 3.16. Fill with Pattern 3.17. Stroke Selection 3.18. Stroke Path 3.19. The “ Preferences ” Command 3.20. Keyboard Shortcuts 3.21. Modules 3.22. Units 4. The “ Select ” Menu 4. 1. Introduction to the “ Select ” Menu 4.2. Select All 4. 3. None 4.4. Invert 4.5. Float 4.6. By Color 4.7. From Path 4. 8. Selection Editor 4.9. Feather 4.10. Sharpen 4.11. Shrink 4.12. Grow 4.13. Border 4.14. Distort 4.15. Rounded Rectangle 4.16. Toggle QuickMask 4.17. Save to Channel 4.18. To Path 5. The “ View ” Menu 5. 1. Introduction to the “ View ” Menu 5.2. New View 5. 3. Dot for Dot 5.4. Zoom 5.5. Shrink Wrap 5. 6. Full Screen 5.7. Navigation Window 5. 8. Display Filters 5.9. Show Selection 5.10. Show Layer Boundary 5.11. Show Guides 5.12. Show Grid 5.13. Show Sample Points 5.14. Snap to Guides 5.15. Snap to Grid 5.16. Snap to Canvas 5.17. Snap to Active Path 5.18. Padding Color 5.19. Show Menubar 5.20. Show Rulers 5.21. Show Scrollbars 5.22. Show Statusbar 6. The “ Image ” Menu 6.1. Overview 6.2. Duplicate 6.3. Mode 6.4. RGB mode 6. 5. Grayscale mode 6. 6. Indexed mode 6.7. Transform 6.8. Flip Horizontally; Flip Vertically 6.9. Rotation 6.10. Guillotine 6.11. Canvas Size 6.12. Fit Canvas to Layers 6.13. Fit Canvas to Selection 6.14. Print Size 6.15. Scale Image 6.16. Crop to Selection 6.17. Autocrop Image 6.18. Zealous Crop 6.19. Merge Visible Layers 6.20. Flatten Image 6.21. Align Visible Layers 6. 22. Guides 6.23. New Guide 6.24. New Guide (by Percent) 6.25. New Guides from Selection 6.26. Remove all guides 6.27. Configure Grid 6.28. Image Properties 7. The “ Layer ” Menu 7. 1. Introduction to the “ Layer ” Menu 7.2. New Layer 7. 3. New Layer Group 7.4. New From Visible 7.5. Duplicate layer 7.6. Anchor layer 7.7. Merge Down 7. 8. Delete Layer 7.9. The Text Commands of the Layer Menu 7.10. Discard Text Information 7.11. “ Stack ” Submenu 7.12. Select Previous Layer 7.13. Select Next Layer 7.14. Select Top Layer 7.15. Select Bottom Layer 7.16. Raise Layer 7.17. Lower Layer 7.18. Layer to Top 7.19. Layer to Bottom 7.20. The “ Reverse Layer Order ” command 7.21. The “ Mask ” Submenu 7.22. Add Layer Mask 7.23.
Apply Layer Mask
7.24. Delete Layer Mask 7.25. Show Layer Mask 7.26. Edit Layer Mask 7.27. Disable Layer Mask 7. 28. Mask to Selection 7.29. Add Layer Mask to Selection 7.30. Subtract Layer Mask from Selection 7. 31. Intersect Layer Mask with Selection 7.32.
The “ Transparency ” Submenu of the “ Layer ” menu
7.33. Add Alpha Channel 7.34. Remove Alpha Channel 7.35. Color to Alpha 7.36. Semi-flatten 7.37. Threshold Alpha 7.38. Alpha to Selection 7.39. Add Alpha channel to Selection 7.40. Subtract from Selection 7.41. Intersect Alpha channel with Selection 7.42. The “ Transform ” Submenu 7.43. Flip Horizontally 7.44. Flip Vertically 7.45. Rotate 90° clockwise 7.46. Rotate 90° counter- clockwise 7.47. Rotate 180° 7.48. Arbitrary Rotation 7.49. Offset 7.50. Layer Boundary Size 7.51. Layer to Image Size 7.52. Scale Layer 7.53. Crop to Selection 7.54. Autocrop Layer 8. The “ Colors ” Menu 8. 1. Introduction to the “ Colors ” Menu 8.2. Colors Tools 8. 3. Invert 8.4. Value Invert 8. 5. Use GEGL 8. 6. The “ Auto ” Submenu 8.7. Equalize 8.8. White Balance 8.9. Color Enhance 8.10. Normalize 8.11. Stretch Contrast 8.12. Stretch HSV 8.13. The “ Components ” Submenu 8.14. Channel Mixer 8.15. Compose 8.16.
Decompose
8.17. Recompose 8.18. The “ Map ” Submenu 8.19. Rearrange Colormap 8.20. Set Colormap 8.21. Alien Map 8.22. Color Exchange 8.23. Gradient Map 8.24. Palette Map 8.25. Rotate Colors 8.26. Sample Colorize 8.27. The “ Info ” Submenu 8.28. Histogram 8.29. Border Average 8.30. Colorcube Analysis 8.31. Smooth Palette 8.32. The Color Filters 8.33. Colorify 8.34. Color to Alpha 8.35. Filter Pack 8.36. Hot 8.37. Max RGB 8.38. Retinex 9. The “ Tools ” Menu 9. 1. Introduction to the “ Tools ” Menu 10. The “ Filters ” Menu 10. 1. Introduction to the “ Filters ” Menu 10.2. Repeat Last 10. 3. Re-show Last 10.4. Reset All Filters 10.5. The “ Python-Fu ” Submenu 10.6. The “ Script-Fu ” Submenu 11. “ Windows ” Menu 12. The “ Help ” Menu 12. 1. Introduction to the “ Help ” Menu 12.2. Help 12.3. Context Help 12.4. Tip of the Day 12.5. About 12.6. Plug-In Browser 12.7. The Procedure Browser 12.8. GIMP online 1. Introduction to Menus
There are many places in GIMP where you can
find menus. The aim of this chapter is to explain all the commands that
are accessible from the image menu bar and the image menu you can get by
right clicking in the canvas. All the context menus and the menu entries
for the other dialogs are described elsewhere in the chapters that
describe the dialogs themselves.
1.1. The Image Menu Bar
This menu bar may contain other entries if you have added script-fus,
python-fus or videos to your GIMP.
1.2. Context Menus
If you right-click on certain parts of the
GIMP interface, a
“ context menu ” opens, which leads to a variety of
functions. Some places where you can access context menus are:
Clicking on an image window displays the Image menu. This is useful
when you are working in full-screen mode , without a menubar.
Clicking on a layer in the Layers Dialog or on a channel in the
Channels Dialog displays functions for the selected layer or
channel.
Right-clicking on the image menubar has the same effect as
left-clicking.
Right- clicking on the title bar displays functions which do not
belong to GIMP ,
but to the window manager program on your computer.
1.3. Tear-off menus
There is an interesting property associated with some of the menus in
GIMP .
These are any of the menus from the Image context menu you get by
right-clicking on the canvas and any of its submenus. (You can tell
that a menu item leads to a submenu because there is an
icon next to it.) When you bring up any of these menus, there is a
dotted line at the top of it (tear-off line). By clicking on this
dotted line, you detach the menu under it and it becomes a separate
window.
Figure 16.1.
The “ windows ” submenu and its tear-off submenu
Tear-off menus are actually independent. They are always visible, their
functions always apply to the current image, and they persist when all
of the images are closed. You can close a tear-off submenu by clicking
on the dotted line again or closing the window from the window manager
on your computer (often by clicking on an X icon in the upper right
corner of the window ).
These tear-off submenus are also created in single-window mode, but are
of less interest since they are masked by the window as soon as you
click on it.
1.4. Tab menus
The following type of menus is not related to the image menu bar, but
for the sake of completeness:
Every dockable dialog
contains a Tab Menu button, as highlighted below. Pressing this Tab
Menu button opens a special menu of tab-related operations , with an
entry at the top that opens into the dialog's context menu .
Figure 16.2. A dockable dialog. A dialog window with the Tab menu button highlighted. The Tab menu.
See Section 2.3.2, “Tab Menu” to learn more about Tab menus.
5.8. Pointer Dialog 2. The “ File ” Menu  Report an error in Bugzilla  8. 21. Alien Map 8.21. Alien Map 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 21. Alien Map 8.21. 1. Overview Figure 16.163. Alien Map filter example Original image Filter applied
This filter renders very modified colors by applying trigonometric
functions. Alien Map can work on images having
RGB and HSV color models.
 8. 21. 2. Activate the filter
You can find this filter in the image window menu under
Colors → Map → Alien Map .  8. 21.3. Options Figure 16.164. Options for the “ Alien Map ” filter Preview
This preview displays results of filter application interactively.
Mode
Radio buttons RGB Color Channel and
HSV Color Channel
let you select the color space you want to use.
Check boxes Modify ... Channel let you
select RGB/HSV Channel you want to work with .
Sliders
For each channel, you can set Frequency (0-5) and Phaseshift
(0-360) of sine-cosine functions, using either sliders or input
boxes and their arrowheads.
Frequency around 0.3 to 0.7 provides a
curve that is similar to the linear function (original image),
only darker or with more contrast. As you raise the frequency
level, you'll get an increasing variation in pixel
transformation, meaning that the image will get more and more
“ alien ” .
Phase alters the value transformation. 0
and 360 degrees are the same as a sine function and 90 is the
same as a cosine function. 180 inverts sine and 270 inverts
cosine.
8.20. Set Colormap 8.22. Color Exchange
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6. 21. Align Visible Layers 6.21. Align Visible Layers 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 21. Align Visible Layers
With the Align Visible Layers command,
you can very precisely position the visible layers (those marked with
the “ eye ” icon). This degree of precision is especially
useful when you are working on animations, which typically have many
small layers. Clicking on Align Visible
Layers displays a dialog which allows you to choose how the layers should be aligned.
Note
In GIMP 1.2 , the default base for the
alignment was the top visible layer in the stack. In
GIMP 2 , the default alignment base is
the edge of the canvas . You can still align the image on the bottom
layer of the stack , even if it is invisible, by checking
Use the (invisible) bottom layer as the base
in the dialog.
Figure 16.73. Example image for layer alignment
The example image contains four layers on a large (150x150 pixel)
canvas. The red square is 10x10 pixels, the green rectangle is
10x20 pixels and the yellow rectangle is 20x10 pixels. The
background layer (blue, 100x100 pixels) will not be affected by
the command, since the Ignore lower layer
option has been checked on the dialog. Note that the layers in the
image seem to have a different order than their actual order in
the stack because of their positions on the canvas. The yellow
layer is the top layer in the image and the second one in the
stack.
 6. 21. 1. Activate the Command
You can access this command from the image menubar through
Image → Align Visible layers .
There is no default keyboard shortcut. If the image holds a single
layer only, you get a message from GIMP telling that there must be
more than one layer in the image to execute the command.  Figure 16.74. The “ Not enough layers ” message 6. 21. 2.
Description of the “ Align Visible Layers ” dialog
Figure 16.75. The “ Align Visible Layers ” dialog Horizontal Style; Vertical Style
These options control how the layers should be moved in
relationship to each other. You can choose:
None :
There will be no change in the horizontal or the vertical
position, respectively.
Collect :
The visible layers will be aligned on the canvas, in the
way that is determined by the Horizontal
base and Vertical base
options. If you select a Horizontal
base of Right edge , layers
may disappear from the canvas. You can recover them by
enlarging the canvas. If you check the
Use the (invisible) bottom layer as the
base option , the layers will be aligned on the
top left corner of the bottom layer.
Figure 16. 76.
Horizontal “ Collect ” alignment ( on the edge of
the canvas )
 Original image with the layer stack
The layers have been moved horizontally so that their
left edges are aligned with the left edge of the
canvas.  Figure 16.77.
Horizontal “ Collect ” alignment (on the bottom
layer)
 Original image with the layer stack
The layers have been moved horizontally so that their
left edges align with the left edge of the bottom
layer.  Fill (left to right) ;
Fill (top to bottom) :
The visible layers will be aligned with the canvas
according to the edge you selected with
Horizontal base or
Vertical base , respectively.
The layers are arranged regularly, so that they do not
overlap each other. The top layer in the stack is placed
on the leftmost (or uppermost) position in the image.
The bottom layer in the stack is placed on the rightmost
(or bottommost) position of the image. The other layers
are placed regularly between these two positions. If the
Use the (invisible) bottom layer as the
base option is checked, the layers are aligned
with the corresponding edge of the bottom layer.
Figure 16. 78.
Horizontal “ Fill ” alignment ( canvas)
Original image with the layer stack
Horizontal filling alignment, Left to Right, with
Use the (invisible) bottom layer as the
base option not checked. The top layer
in the stack, the green one, is placed all the way
on the left. The bottom layer in the stack , the red
one, is placed is on the right and the yellow layer
is between the other two.
Figure 16.79.
Horizontal “ Fill ” alignment ( bottom layer)
Original image with the layer stack The same parameters as in the previous example,
but with the lowest (blue) level as the base.
Fill (right to left) ;
Fill (bottom to top) :
These settings work similarly to the ones described above,
but the filling occurs in the opposite direction.
Figure 16.80.
Vertical “ Fill ” alignment (bottom layer)
Original image with the layer stack
Vertical “ Fill ” alignment, bottom to
top, bottom layer as base
There must be at least three visible layers in the image to
use the “ Fill ” options.
6.20. Flatten Image 6.22. Guides
 Report an error in Bugzilla  15. 8. Playback 15.8. Playback 15. Animation Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. 8. Playback 15.8. 1. Overview
This plug-in lets you play an animation from a multi-layers image (that
could be saved in the GIF, MNG or even XCF format), to test it.
 15. 8. 2. Activate the filter
You can find this filter through
Filters → Animation → Playback  15. 8.3. Options Figure 17. 368. “ Playback ” filter options This dialog has: Preview
This preview of the animation automatically fits the frame size.
The number of the displayed frame is shown below the preview.
Buttons Three buttons are available: Play/Stop Play/Stop
to play or stop the animation.
Rewind Rewind
to re-launch the animation from start.
Step Step to play the animation step by
step.
15.7. Optimize 16. Alpha to Logo Filters  Report an error in Bugzilla  3. 2. Antialias 3.2. Antialias 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 2. Antialias 3.2. 1. Overview
This filter reduces alias effects
(see Antialiasing )
using the Scale3X edge-extrapolation algorithm.
Scale3X is derived from Scale2X, which is a graphics effect to increase
the size of small bitmaps guessing the missing pixels without
interpolating pixels and blurring the images. [13]
Scale2X was originally developed to improve the quality of old Arcade
and PC games with a low video resolution played with video hardware like
TVs, Arcade monitors, PC monitors and LCD screens. [14]
The Antialias filter works as follows:
For every pixel,
the filter expands the original pixel in 9 (3x3) new pixels
according to the Scale3X algorithm, using the colors of the pixel
and its 8 adjacent pixels (extrapolation);
then the filter subsamples the new pixels to a weighted average
pixel.
 3. 2. 2. Activating the filter
You can find this filter through
Filters → Enhance → Antialias .  3. 2.3. Examples
The following examples illustrate the effect on some patterns. The
small squares are one pixel in size (zoom 16:1).
Original image (zoom 16:1) “ Antialias ” applied (zoom 16:1) [13] [ SCALE2X ] .
[14] [ AdvanceMAME ] .
3. Enhance Filters 3.3. Deinterlace
 Report an error in Bugzilla  10. 2. Apply Canvas 10. 2. Apply Canvas 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 2. Apply Canvas 10. 2. 1. Overview Figure 17. 168. Example for the “ Apply Canvas ” filter Original image Filter “ Apply Canvas ” applied
This filter applies a canvas-like effect to the current layer or
selection . It textures the image as if it were an artist's canvas.
 10. 2. 2. Activate the filter
You can find this filter through
Filters → Artistic → Apply Canvas... .  10. 2.3. Options Figure 17. 169. “ Apply Canvas ” options Preview
Your changes are displayed in this preview before being applied
to your image.
Direction
Direction sets the starting direction of the canvas render. You
can also consider that this option gives you the position of the
light source which lightens the canvas.
Depth
The Depth slider controls the apparent depth of the rendered
canvas effect from 1 (very flat) to 50 (very deep).
10. Artistic Filters 10.3. Cartoon
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5. 10. Apply Lens 5.10. Apply Lens 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 10. Apply Lens 5. 10. 1. Overview Figure 17. 122. The same image, before and after applying lens effect. Original image Filter “ Apply lens ” applied
After applying this filter, a part of the active layer is rendered as
through a spherical lens.
 5.10. 2. Activate the filter
You can find this filter in the image window menu through
Filters → Light and Shadow → Apply Lens  5. 10.3. Options Figure 17. 123.  “ Apply Lens ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Keep original surroundings The lens seems to be put on the active layer. Set surroundings to background color
The part of the active layer outside the lens will have the
background color selected in the toolbox.
Make surroundings transparent
The part of the active layer outside the lens will be transparent.
This option exists only if the active layer has an alpha channel .
Lens refraction index Lens will be more or less convergent (1-100). 5.9. Xach-Effect 5. 11. Glass Tile
 Report an error in Bugzilla  7. 54. Autocrop Layer 7.54. Autocrop Layer 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 54. Autocrop Layer
The Autocrop Layer command automatically
crops the active layer, unlike the
Crop Tool , or the
Crop Layer command which let you
manually define the area to be cropped.
This command removes the largest possible area around the outside edge
which all has the same color. It does this by scanning the layer along a
horizontal line and a vertical line and cropping the layer as soon as it
encounters a different color, whatever its transparency.
You can use this command to crop the layer to the dimensions of a subject
that is lost in a solid background which is too large.
 7. 54. 1. Activating the Command
You can access this command from the image menubar through
Layer → Autocrop Layer .  7. 54.2. Example Figure 16.119. Example
Before applying “ Autocrop Layer ”
After applying “ Autocrop Layer ” : the active layer,
up, has been cropped to the size of the circle it contains. Its
size is reduced, and the unoccupied part in the canvas is
transparent, revealing the yellow and green colors of the
underlying layer.
7.53. Crop to Selection 8. The “ Colors ” Menu  Report an error in Bugzilla  6. 17. Autocrop Image 6. 17. Autocrop Image 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 17. Autocrop Image
The Autocrop Image command removes the
borders from an image. It searches the active layer for the largest
possible border area that is all the same color, and then crops this
area from the image, as if you had used the
Crop tool.
Caution
Note carefully that this command only uses the
active layer
of the image to find borders. Other layers are cropped according to
the same limits as limits in the active layer.
 6. 17. 1. Activate the Command
You can access this command from the image menubar through
Image → Autocrop Image .  6. 17. 2. Example Figure 16.69. “ Autocrop ” example
This image is made of three layers. One with a red square,
another with a green square; both on a yellow semi-transparent
background. The green layer is active.
“ Autocrop ” has cropped the green square and made a
layer from it. The other layers have been cropped to the same
size as the green one. Only a small part of the red square has
been kept.
6.16. Crop to Selection 6.18. Zealous Crop
 Report an error in Bugzilla  8. 12. Stretch HSV 8.12. Stretch HSV 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 12. 1. Activate the Command
You can access this command from the image menubar through
Colors → Auto → Stretch HSV .  8. 12.2. “ Stretch HSV ” example Figure 16.142. Original image
The active layer and its Red, Green and Blue histograms
before “ Stretch HSV ” .
Figure 16.143. Image after the command
The active layer and its Red, Green and Blue histograms after
“ Stretch HSV ” .
Contrast, luminosity and hues are enhanced.
8.11. Stretch Contrast 8.13. The “ Components ” Submenu  Report an error in Bugzilla 
4. 2. Blinds 4.2. Blinds 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 2. Blinds 4. 2. 1. Overview Figure 17. 35. Applying example for the Blinds filter Original image Filter “ Blinds ” applied
It generates a blind effect with horizontal or vertical battens. You can
lift or close these battens, but not lift the whole blind up.
 4. 2. 2. Activating the filter
You can find this filter through
Filters → Distort → Blinds .  4. 2.3. Options Figure 17. 36. “ Blinds ” filter options Preview
All your setting changes will appear in the Preview without
affecting the image until you click on OK . Orientation
Allows you to decide whether battens will be horizontal or
vertical.
Background
The batten color is that of the Toolbox Background. To be able to
use the Transparent option, your image must
have an Alpha channel.
Displacement
Slider and input box allow to wide battens giving the impression
they are closing, or to narrow them, giving the impression they
are opening.
Number of segments
It's the number of battens.
4. Distort Filters 4.3. Curve Bend
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2. 2. Blur 2.2. Blur 2. Blur Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 2. Blur 2. 2. 1. Overview Figure 17. 8. The Blur filter applied to a photograph Original Blur applied
The simple Blur filter produces an effect similar to that of an out of
focus camera shot. To produce this blur effect, the filter takes the
average of the present pixel value and the value of adjacent pixels and
sets the present pixel to that average value.
Filter advantage is its calculation speed. It suits big images.
Filter disadvantage is that its action is hardly perceptible on big
images, but very strong on small images.
 2. 2. 2. Activate the filter
You can find this filter through:
Filters → Blur → Blur 
2. Blur Filters 2. 3. Gaussian Blur
 Report an error in Bugzilla  8. 29. Border Average 8. 29. Border Average 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 29. 2. Activating the filter
This filter is found in the image window menu under
Colors + Info → Border Average .  8. 29.3. Options Figure 16.178. Options of the “ Border Average Filter ” Border Size
You can set there the border Thickness in
pixels.
Number of Colors
The Bucket Size lets you control the number
of colors considered as similar and counted with the same
“ bucket ” . A low bucket size value (i.e. a high bucket
number) gives you better precision in the calculation of the
average color. Note that better precision does not necessarily
mean better results (see example below).
8.29.4.
Examples illustrating the “ Border Average ” filter
Figure 16.179. Original image
Original image: colors are pure Red (255;0;0), pure Blue
(0;0;255), and different but similar kinds of Green
( 0;255;0 , 63;240;63 , 48;224;47 , 0;192;38 ).
Figure 16.180. “ Number of Colors ” is set to 8:
The resulting color is a Red (254,2,2).
The bucket size is low. So the bucket number is high. All color shades
can be stored in different buckets. Here, the bucket containing red is
the most filled. The resulting color is a nearly pure
Red (254,2,2) and becomes the foreground color of the Toolbox.
Figure 16.181. “ Number of Colors ” is set to 64:
The resulting color is Green (32,224,32) .
Here the bucket size is high, the number of buckets low. Similar colors
(here green) are stored in a same bucket. This “ green ”
bucket is now the most filled.
All colors in this bucket have the same values for the two most
significant bits: (00******;11******;00******). The remaining 6 bits
may have any values from 0 to 63 for the respective channel. So
in this bucket, color red channels range from 0 to 63, green channels
from 192 to 255, blue channels from 0 to 63. The resulting color is
Green (32,224,32) , which, for every channel, is the average between the
limits of the channel range (63 + 0)/2, (255+192)/2 , (63+0)/2.
8.28. Histogram 8.30. Colorcube Analysis
 Report an error in Bugzilla  12.2. Bump Map 12. 2. Bump Map 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 2. Bump Map 12. 2. 1. Overview Figure 17. 246. “ bump-map ” example
On the left, the original image that we want to emboss: a solid
blue. In the middle, the bump map : a grayscale image, where
black pixels will emboss backwards and white pixels will emboss
forwards. On the right, the bump-mapped image. The filter adds a
shadow effect.
This filter creates a 3D effect by embossing an image (the card) and
then mapping it to another image. Bump height depends on pixel
luminosity and you can set light direction. See
Emboss for more information
about embossing. You can bump map any type of image, unlike the Emboss
filter.
 12. 2. 2. Activate the filter
This filter is found in the image window menu under
Filters → Map → Bump Map .  12. 2.3. Options Figure 17. 247.  “ Bump Map ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Bump map
This drop-down list allows you to select the image that will be
used as a map for bump-mapping. This list contains images that are
present on your screen when you launch the filter. Images opened
after starting filter are not present in this list.
Map type
This option allows you to define the method that will be used
when creating the map image:
Linear
Bump height is a direct function of luminosity.
Sinusoidal
Bump height is a sinusoidal function of luminosity.
Spheric
Bump height is a spheric function of luminosity.
Compensate for darkening
Bump-mapping tends to darken image. You can compensate this
darkening by checking this option.
Invert bumpmap
Bright pixels default to bumps and dark pixels to hollows. You can
invert this effect by checking this option.
Tile bumpmap
If you check this option , there will be no relief break if
you use your image as a pattern for a web page : patterns will
be placed side by side without any visible joins.
Azimut
This is about lighting according to the points of the compass
(0 - 360). East (0°) is on the left. Increasing value goes
counter-clockwise.
Elevation
That's height from horizon (0 .50°), up to zenith (90°).
Depth
With this slider, you can vary bump height and hollow depth. The
higher the value, the higher the difference between both. Values
vary from 1 to 65.
X offset, Y offset
With this slider, you can adjust the map image position
compared with the image, horizontally (X) and/or vertically
(Y).
Waterlevel
If your image has transparent areas, they will be treated like
dark areas and will appear as hollows after bump-mapping. With this
slider, you can reduce hollows as if sea level was raising. This
hollows will disappear when sea level value reaches 255. If the
Invert bump-map option is checked, transparent areas will be
treated as bright areas, and then Waterlevel slider will plane
bumps down.
Ambient
This slider controls the intensity of ambient light. With high
values, shadows will fade and relief lessen.
12. Map Filters 12.3. Displace
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8. 11. Stretch Contrast 8.11. Stretch Contrast 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 11. 1. Activate the Command
This command can be accessed from an image menubar as
Colors → Auto → Stretch Contrast .  8. 11.2. “ Stretch Contrast ” Example Figure 16. 140. Original image
The layer and its Red , Green and Blue histograms before
“ Stretch Contrast ” .
Figure 16.141. Image after the command
The layer and its Red and Green and Blue histograms after
“ Stretch Contrast ” .
The pixel columns do not reach the right end of the histogram
(255) because of a few very bright pixels, unlike
“ White Balance ” .
Histogram stretching creates gaps between the pixel columns,
giving it a stripped look.
8.10. Normalize 8.12. Stretch HSV
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10. 3. Cartoon 10.3. Cartoon 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 3. Cartoon 10. 3. 1. Overview Figure 17. 170. Example for the “ Cartoon ” filter Original image Filter “ Cartoon ” applied
The Cartoon filter modifies the active layer or selection so that it
looks like a cartoon drawing. Its result is similar to a black felt pen
drawing subsequently shaded with color. This is achieved by darkening
areas that are already distinctly darker than their neighborhood.
 10. 3. 2. Activate the filter
You can find this filter in
Filters → Artistic → Cartoon .  10. 3.3. Options Figure 17. 171. “ Cartoon ” filter options Mask radius
This parameter controls the size of areas the filter works with.
Large values result in very thick black areas and much less detail
in the resulting image. Small values result in more subtle pen
strokes and more details preserved.
Percent black
This parameter controls the amount of black color added to the
image. Small values make the blend from color regions to blackened
areas smoother and dark lines themselves thinner and less
noticeable. Larger values make the lines thicker, darker and
sharper. The maximum value makes the lines aliased. The best, most
natural results are usually achieved with an intermediate value.
10.2. Apply Canvas 10. 4. Clothify
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8. 30. Colorcube Analysis 8.30. Colorcube Analysis 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 30. 2. Activating the filter
You can find this filter in the image window menu under
Colors → Info → Colorcube Analysis .  8. 29. Border Average 8. 31. Smooth Palette
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13. 8. Checkerboard 13.8. Checkerboard 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 8. Checkerboard 13. 8. 1. Overview Figure 17. 297. Example for the Checkerboard filter Filter “ Checkerboard ” applied Psychobilly “ Checkerboard ”
This filter creates a checkerboard pattern replacing the current layer
content. Colors used for pattern are current Fore- and Back ground
colors of toolbox.
13. 8. 2. Starting filter
You can find this filter in the image menu through
Filters → Render → Pattern → Checkerboard
13. 8.3. Options Figure 17. 298. “ Checkerboard ” filter options Size
With this option, you can set checkerboard square size, in
pixels, or in your chosen unit by using the drop-down list.
Psychobilly
This option gives an eiderdown look to the Checkerboard.
13.7. IFS Fractal 13. 9. CML Explorer
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13. 9. CML Explorer 13. 9. CML Explorer 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 9. CML Explorer 13. 9. 1. Overview Figure 17. 299. Example for the “ CML Explorer ” filter
Filter “ CML Explorer ” applied with default options
This filter is the king of texture creating filters. It is extremely
efficient but very complex. It uses a mathematical method named Cellular
Automata [ WKPD-CA ] .
 13. 9. 2. Activating the filter
You can find this filter from the image menu through
Filters → Render → Pattern → CML Explorer .  13. 9.3. Options General Options
Filter options are distributed among
Hue , Saturation ,
Value , Advanced ,
Others and Misc Ops.
tabs. Some more options are available. They will be described
in following section.
Preview
This filter offers you a Preview where you can see the
result of your settings before they are applied to the
image.
New Seed, Fix Seed, Random Seed
Random plays a large part in creating patterns. With these
options, you can influence the way random is generated. By
clicking on the New Seed button, you
can force random to use a new source of random. The preview
will show you the result.
Fix Seed lets you keep the same seed
and so to reproduce the same effect with the filter.
Random Seed generates a random seed
at random.
Open, Save
With these both command buttons you can save pattern
settings in a file, and to get them back later.
“ CML Explorer ” filter options ( Hue) Figure 17.300. Hue tab
This filter works in the
HSV color model . In this tab, you
can set options for Hue.
Function type
In this drop-down list, you can select the method that
will be used to treat the current layer. These methods
are:
Keep image's values
With this option, image hue values will be kept.
Keep the first value
With this option, starting color will be standard cyan.
Fill with parameter k
Pattern look will depend on k that
you will set later in options.
Miscellaneous f(k)
See above, “ Fill with k parameter ” .
Delta function , Delta function stepped
// TODO
sin^p-based function , sin^p, stepped
These options create wave-like patterns, like aurora
borealis or curtain folds.
Composition
Here, these options concern Hue. You can choose among several
functions, and a book could be filled with results of all these
functions. Please, experiment!
Misc. arrange
This drop-down list offers you several other parameters.
Also a book would be necessary to explain all possibilities of
these parameters.
Use cyclic range
// TODO
Mod. rate
With this slider and the input box, you can set
modification rate from 0.0 to 1.0 . Low value results in a
lined pattern.
Env. sensitivity
Value is from 0.0 to 1.0
Diffusion dist.
Diffusion distance: from 2 to 10.
# of subranges
Number of sub-rangers: from 1 to 10.
(P)ower factor
With this option you can influence the
Function types using the
p parameter. Value from 0.0 to 10.0.
Parameter k
With this option you can influence the
Function types using the
k parameter. Value from 0.0 to 10.0.
Range low
Set lower limit of hue that will be used for calculation. values vary from 0.0 to 1.0 .
Range high
Set the upper limit of hue that will be used for
calculation. Variations are from 0.0 to 1.0 .
Plot a Graph of the Settings
By clicking on this large button, you can open a window
that displays the graph of hue present settings.
Figure 17.301. Function graph of present settings “ CML Explorer ” filter options ( Saturation) Figure 17.302. Saturation tab
In this tab, you can set how Saturation component of the HSV
color model will be used in pattern calculation.
These options are similar to Hue tab options.
“ CML Explorer ” filter options ( Value) Figure 17.303. Value tab
In this tab, you can set how the Value (Luminosity) component of
the HSV color model will be used in pattern calculation.
These options are similar to Hue tab options.
“ CML Explorer ” filter options ( Advanced) Figure 17.304. Advanced tab
These tab settings apply to the three HSV channels.
Channel sensitivity // TODO Mutation rate // TODO Mutation distance // TODO “ CML Explorer ” filter options ( Others) Figure 17.305. Others tab
In this tab, you can find various parameters about image display
and random intervention.
Initial value // TODO Zoom scale // TODO Start offset // TODO Seed of Random // TODO “ CML Explorer ” filter options ( Misc Ops.) Figure 17.306. Miscellaneous options tab
In this tab you can find various options about copy and loading.
Copy Settings
These options allow you to transfer information from
one of the HSV channel to another one.
Selective Load Settings
With the Open button of this
filter, you can load previously loaded settings. If you
don't want to load all of them, you can select a source
and a destination channel here.
13.8. Checkerboard 13.10. Diffraction Patterns
 Report an error in Bugzilla  8. 9. Color Enhance 8.9. Color Enhance 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 9. 1. Activate the command
You can access this command from the image menubar through
Colors → Auto → Color Enhance .  8. 9.2. “ Color Enhance ” example Figure 16. 136. “ Color Enhance ” example ( Original image)
The active layer and its Red, Green and Blue
histograms before “ Color Enhance ” .
Figure 16.137.
“ Color Enhance ” example ( Image after the command)
The active layer and its Red, Green and Blue histograms after
“ Color Enhance ” . The result may not always be
what you expect.
8.8. White Balance 8.10. Normalize
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8. 33. Colorify 8.33. Colorify 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 33. 2. Activate the filter
This filter is found in the image window menu under
Colors → Colorify .  8. 33.3. Options Figure 16.186. “ Colorify ” filter options
A color palette is available containing especially the
RGB colors Red, Green, Blue and the
CMY colors Cyan, Magenta, Yellow.
You can select your own color by clicking on the Custom
Color swatch.
8.32. The Color Filters 8.34. Color to Alpha
 Report an error in Bugzilla  8. 19. Rearrange Colormap 8.19. Rearrange Colormap 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 19. Rearrange Colormap Figure 16.159. The “ Rearrange Colormap ” window
This command allows you to re-organize colors in the palette of
indexed images. It doesn't modify the image. You
can't add or remove colors; for that, see
The Indexed Palette Dialog
.
8.19. 1. Activate Dialog
You can access this command from the image menu-bar through
Colors → Map → Rearrange Colormap .
If your image is not indexed, this command is grayed out and disabled.
8.19.2. Using the “ Rearrange Colormap ” dialog
Explanations supplied in the dialog window are enough: drag
and drop colors to rearrange the colormap. You can sort colors in
various ways by using the local pop- menu that you get by right-clicking :
Figure 16.160. The “ Rearrange Colormap ” pop-menu 8.18. The “ Map ” Submenu 8.20. Set Colormap
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8. 14. Channel Mixer 8.14. Channel Mixer 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Report an error in Bugzilla 
8. 34. Color to Alpha 8.34. Color to Alpha 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 34. 2. Activate the filter
This filter is found in the image window menu under
Colors → Color to Alpha .  8. 34.3. Options Figure 16.188. “ Color to Alfa ” command options Color
Clicking on the From color swatch
provides a color selection dialog where you can select a
color. If selection of a precise color is required, use
the Color Picker then drag and drop the selected color
from the color picker to the From color swatch. Right
clicking on the color will display a menu where you can
select Foreground or Background colors, White or Black.
8.33. Colorify 8.35. Filter Pack
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8. 15. Compose 8.15. Compose 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  Report an error in Bugzilla  8. 2. Convolution Matrix 8. 2. Convolution Matrix 8. Generic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 2. Convolution Matrix 8. 2. 1. Overview
Here is a mathematician's domain. Most of filters are using convolution
matrix. With the Convolution Matrix filter, if the fancy takes you, you
can build a custom filter.
What is a convolution matrix? It's possible to get a rough idea of it
without using mathematical tools that only a few ones know. Convolution
is the treatment of a matrix by another one which is called
“ kernel ” .
The Convolution Matrix filter uses a first matrix which is the Image to
be treated. The image is a bi-dimensional collection of pixels in
rectangular coordinates. The used kernel depends on the effect you want.
GIMP uses 5x5 or 3x3 matrices. We will consider only 3x3 matrices, they
are the most used and they are enough for all effects you want. If all
border values of a kernel are set to zero, then system will consider it
as a 3x3 matrix.
The filter studies successively every pixel of the image . For each of
them, which we will call the “ initial pixel ” , it
multiplies the value of this pixel and values of the 8 surrounding
pixels by the kernel corresponding value . Then it adds the results,
and the initial pixel is set to this final result value.
A simple example:
On the left is the image matrix: each pixel is marked with its value.
The initial pixel has a red border . The kernel action area has a green
border. In the middle is the kernel and, on the right is the convolution
result.
Here is what happened: the filter read successively, from left to right
and from top to bottom, all the pixels of the kernel action area. It
multiplied the value of each of them by the kernel corresponding value
and added results. The initial pixel has become 42:
(40*0)+(42*1)+(46*0) + (46*0)+(50*0)+(55*0) + (52*0)+(56*0)+(58*0) = 42.
(the filter doesn't work on the image but on a copy). As a graphical
result, the initial pixel moved a pixel downwards.
 8. 2. 2. Activating the filter
This filter is found in the image window menu under
Filters → Generic → Convolution Matrix .  8. 2.3. Options Figure 17. 150. “ Convolution matrix ” options Matrix
This is the 5x5 kernel matrix: you enter wanted values directly
into boxes.
Divisor
The result of previous calculation will be divided by this
divisor. You will hardly use 1, which lets result unchanged,
and 9 or 25 according to matrix size, which gives the
average of pixel values.
Offset
This value is added to the division result. This is useful
if result may be negative. This offset may be negative.
Border
When the initial pixel is on a border, a part of kernel is out of
image. You have to decide what filter must do:
From left: source image, Extend border,
Wrap border, Crop border
Extend This part of kernel is not taken into account . Wrap
This part of kernel will study pixels of the opposite
border, so pixels disappearing from one side reappear on the
other side.
Crop
Pixels on borders are not modified, but they are cropped.
Channels
You can select there one or several channels the filter will work
with.
Normalise
If this option is checked , The Divisor takes the result value of
convolution. If this result is equal to zero (it's not possible
to divide by zero), then a 128 offset is applied. If it is
negative (a negative color is not possible), a 255 offset is
applied (inverts result).
Alpha-weighting
If this option is not checked, the filter doesn't take in account
transparency and this may be cause of some artefacts when
blurring.
8.2.4. Examples
Design of kernels is based on high levels mathematics. You can find
ready-made kernels on the Web. Here are a few examples:
Figure 17.151. Sharpen Figure 17.152. Blur Figure 17.153. Edge enhance Figure 17.154. Edge detect Figure 17.155. Emboss 8. Generic Filters 8.3. Dilate
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10. 5. Cubism 10.5. Cubism 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 5. Cubism 10. 5. 1. Overview Figure 17. 174. Example for the “ Cubism ” Original image Filter “ Cubism ” applied
The Cubism plug-in modifies the image so that it appears to be
constructed of small squares of semitransparent tissue paper.
Tip
If setting possibilities of this filter are not enough for you, see
GIMPressionist filter
which offers more options.
 10. 5. 2. Activate the filter
You can find this filter through
Filters → Artistic → Cubism  10. 5.3. Options Figure 17. 175. “ Cubism ” filter options Preview
Your changes are displayed in this preview before being applied
to your image.
Tile size
This variable determines the size, in pixels, of the squares to
be used. This is, in effect, the size of the little squares of
tissue paper used in generating the new image. The slider can be
used, the exact pixel size can be entered into the text box, or
the arrow buttons can be used.
Tile saturation
This variable specifies how intense the color of the squares
should be. This affects the opacity of the squares. A high value
will render the squares very intensely and does not allow lower
squares to show through. A lower value allows the lower squares
to be more visible through the higher ones and causes more
blending in the colors. If this is set to 0 and Use Background
Color is not checked, the entire layer will be rendered black.
If it is checked and the value here is zero, the background
color will fill the entire layer.
Use background color
This filter creates its tiles from all the colors of the image
and paint them with a color scale which depends on the Tile
Saturation. With a low Tile Saturation, this color scale lets the
background color appear: default is black as you can see by
setting Tile Saturation to 0. When this option is checked , the
background color of the Toolbox is used . If your image has an
Alpha channel , this color scale will also be transparent.
Figure 17.176.
Example illustrating the action of the “ Use BackGround
color ” option
The original image and the color area of Toolbox. BG color
is blue.
Figure 17.177. The option is not checked The option is not checked . On the left is no Alpha:
background is black. On the right is Alpha: background is
transparent black.
Figure 17.178. The option is checked
The option is checked. On the left, no Alpha: background is
blue. On the right, with an Alpha channel, background is
transparent blue.
Tip
If you are using this to generate background images for web pages and
the like, work with a small range of colors painted randomly on a
small square. Then apply the Cubism filter with the desired settings.
As a last step, try
Make Seamless
to adjust the image so it will tile seamlessly in your background.
10.4. Clothify 10.6. GIMPressionist
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4. 3. Curve Bend 4.3. Curve Bend 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 3. Curve Bend 4. 3. 1. Overview Figure 17. 37. Applying example for the Curve Bend filter Original image Filter “ Curve Bend ” applied
This filter allows you to create a curve that will be used to distort
the active layer or selection. The distortion is applied gradually
from an image or selection border to the other.
 4. 3. 2. Activating the filter
You can find this filter through
Filters → Distorts → Curve Bend .  4. 3.3. Options Figure 17. 38. “ Curve bend ” filter options Preview
The preview displays changes to image or selection without
modifying the image until you press OK .
Preview once
This button allows you to update the preview each time you
need it.
Automatic Preview
With this option, preview is changed in real time. This
needs much calculation and may lengthen work. It is
particularly evident when using “ Rotation ” .
Options Rotate
There, you can set the application angle of filter (0-360
counter-clockwise). 0 is default setting: The curve will be
applied from the upper border and/or from the lower. Set to
90, it will be applied from left border and/or from the
right one.
Smoothing, Antialiasing
The distort process may create hard and stepped borders.
These two options improve this aspect.
Work on copy
This option creates a new layer called
“ Curve_bend_dummy_layer_b ” which becomes the
active layer, allowing you to see changes to your
image in normal size without modifying the original image
until you press the OK button.
Modify Curves
In this grid, you have a marked horizontal line, with a node at
both ends, which represents by default the upper border of image.
If you click on this curve, a new node appears, that you can drag
to modify the curve as you want. You can create several nodes on
the curve.
You can have only two curves on the grid, one for the so named
“ upper ” border and the other for the so named
“ lower ” border. You can activate one of them by
checking the Upper or
Lower radio button.
If you use the Free Curve
Type option, the curve you draw will replace the active
curve.
Curve for Border
There you can select whether the active curve must be applied to
the Upper or the Lower
border, according to the
rotation.
Caution
Remember that the curve border depends on the rotation. For
example, with Rotate = 90° the upper curve
will actually be applied to the left border.
Curve Type
With the Smooth , you get automatically a well
rounded curve when you drag a node.
The Free option allows you to draw a curve
freely. It will replace the active curve.
Buttons Copy Copy the active curve to the other border. Mirror Mirror the active curve to the other border. Swap
Swap the Upper and
Lower curves.
Reset Reset the active curve. Open Load the curve from a file. Save Save the curve to a file. 4.2. Blinds 4.4. Emboss
 Report an error in Bugzilla  12.7. The Procedure Browser 12.7. The Procedure Browser 12. The “ Help ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 7. The Procedure Browser
The Procedure Browser command displays the
procedures in the PDB , the Procedure
Database. These procedures are functions which are called by the scripts
or plug-ins.
 12. 7. 1. Activating the Command
You can access this command from the image menubar through
Help → Procedure Browser  12. 7. 2.
Description of the “ Procedure Browser ” dialog window
Figure 16. 213.
The “ Procedure Browser ” dialog window
The figure above shows the Procedure Browser
dialog window. If you click on an item in the scrolled list on the
left, information about it is displayed on the right . You can also
search for a specific procedure by querying the procedural database
with a regular expression on Search: text box:
by name
Shows a list of procedures which have code names that contain
the part of name you entered.
by description
Shows a list of procedures which have blurbs that contain
the word you entered.
by help
Shows a list of procedures which have additional information
text that contain the word you entered.
by author
Shows a list of procedures which created by the author
which has the part of name you entered.
by copyright
Shows a list of procedures which copyright are hold by
someone that have the part of name you entered.
by date
Shows a list of procedures which have date of year
that match the year you entered.
Note
This query is processed with text but not date value, so
you cannot find some procedure entries even if their date
contains the year you entered. For example, a procedure
dated 2000-2005 does not match if you search
procedures with 2001, but it matches with 2000 or 2005.
by type
Shows a list of procedures which have a one of four types:
“ Internal GIMP procedure ” , “ GIMP Plug-In
” , “ GIMP Extension ” , or “ Temporary
Procedure ” .
12.6. Plug-In Browser 12.8. GIMP online  Report an error in Bugzilla 
8. 16. Decompose 8. 16.
Decompose
8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 16. 2. Activate the command
You can find this command in the image window menu under
Colors → Components → Decompose… .  8. 16. 3. Options Figure 16.156. “ Decompose ” command options Extract Channels
Following options are described with
Decompose to
layers checked.
Color model RGB
If the RGB radio button is clicked, a grey level image is
created with three layers ( Red, Green and Blue), and two
channels (Grey and Alpha).
This function is interesting when using Threshold tool. You
can also perform operations like cutting, pasting or moving
selections in a single RBG channel. You can use an
extracted grayscale as a selection or mask by saving it in
a channel (right-click & gt;Select & gt;Save to a channel).
RGBA
If the RGBA radio button is clicked, a image is created
similar at the RGB Decomposing with a additional Alpha
layer filled with the transparencies values of the source
image. Full transparent pixels are black and the full
opaque pixels are white.
HSV
This option decomposes image into three greyscaled layers,
one for Hue, one for Saturation and another for Value.
Although Hue is greyscaled, it does
represent hues. In color circle, white and black are
starting and arrival points and are superimposed. They
represent Red color at top of circle. Grey intermediate
levels are corresponding to intermediate hues on circle:
dark grey to orange, mid grey to green and light grey to
magenta.
Saturation and
Value : White is maximum Saturation
(pure color) and maximum Value (very bright). Black is
minimum Saturation (white) and minimum Value (black).
HSL
This option is similar to HSV . Instead
of the V alue, the third layer contains
the image's L component.
CMY
This option decomposes image into three greyscaled layers,
one for Yellow, one for Magenta and another for Cyan.
This option might be useful to transfer image into printing
softwares with CMY capabilities.
CMYK
This option is similar at the CMY Decomposing
with an additional layer for Black.
This option might be useful to transfer image into printing
softwares with CMYK capabilities.
Alpha
This option extracts the image transparency stored in the
Alpha channel in
Channel dialog
in a separate image. The full transparent pixels are Black
the full opaque pixels are white. The graytones are smooth
transitions of the transparency in the source image.
LAB
This option decomposes image into three greyscaled layers,
layer “ L ” for Luminance, layer
“ A ” for colors between green and red, layer
“ B ” for colors between blue and yellow.
The LAB Decomposing is a color model of the Luminance-Color
family. A channel is used for the Luminosity while two other
channels are used for the Colors.
The LAB color model is used by Photoshop.
YCbCr
In GIMP there is four YCbCr
decompositions with different values.
Each option decomposes image in three greyscaled layers, a
layer for Luminance and two other for blueness and redness.
The YCbCr color model also called YUV is now used for
digital video (initially for PAL analog video). It's based
on the idea that the human eye is most sensitive to
luminosity, next to colors. The YCbCr Decomposing use a
transformation matrix and the different options are
different values recommended by ITU (International
Telecommunication Union) applied to the matrix .
Decompose to Layers
If this option is checked , a new grey-scaled image is created ,
with each layer representing one of the channels of the selected
mode. If this option is not checked, every channel is represented
with a specific image automatically and clearly named in the name
bar.
Foreground as registration color Example 16.1. Crop marks Source image Cyan component Black component (Magenta and Yellow components omitted.)
This option is for specialists. It is related to CMYK printing.
When checked, every pixel of the current foreground color will
be black in each component of the decomposed images/layers. This
allows you to make crop marks visible on all channels, providing
a useful reference for alignment. A thin cross printed in
registration black can also be used to check whether the printing
plates are lined up.
8.15. Compose 8.17. Recompose
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3. 3. Deinterlace 3.3. Deinterlace 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 3. Deinterlace 3.3. 1. Overview
Images captured by videocards, especially when fast movement is
recorded, may look blurred and stripped, with split objects. This is
due to how cameras work. They don't record 25 images per second, but 50,
with half vertical resolution. There are two interlaced images in one
frame. First line of first image is followed by first line of second
image followed by second line of first image... etc. So, if there have
been an important move between the two images, objects will appear
split, shifted, stripped.
The Deinterlace filter keeps only one of both images and replaces
missing lines by a gradient between previous and following lines. The
resulting image, or selection, will be somewhat blurred, but can be
improved by enhance filters
You can find interlaced images at
[ WKPD-DEINTERLACE ] .
 3.3. 2. Activating the filter
You can find this filter through
Filters → Enhance → Deinterlace .  3. 3.3. Options Figure 17. 21.  Deinterlace filter options Preview
If checked, parameter setting results are interactively displayed
in preview.
Keep odd fields, Keep even fields
One of them may render a better result.  You must try both.
3.3.4. Example Figure 17.22. Simple applying example for the Deinterlace filter
Top: even lines pixels are shifted by one pixel to the right.
Bottom: one line is missing. These images are zoomed to show
pixels.
“ Keep even fields ” checked.
Top: odd lines have been shifted to the right, to align
themselves with the even lines. Bottom: the empty line has been
filled with red.
“ Keep odd fields ” checked.
Top: even lines have been shifted to the left, to align
themselves with the odd lines. Bottom: the empty line persists,
but joins up and down through a gradient.
3.2. Antialias 3.4. Despeckle
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9.2. Depth Merge 9.2. Depth Merge 9. Combine Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  9. 2. Depth Merge
Depth Merge is a Combine Filter which is useful to combine two different
pictures or layers. You can decide which part of every image or layer will
stay visible.
9. 2.1. Overview Figure 17. 161. Filter example Original Filter applied
Every image is associated with a map which works as a mask. Simply
create this map as a grayscale gradient: when applied onto the image,
dark areas of the mask will show the underlying image and bright areas
will mask the image.
Note
To work with this filter, images and maps must have the same size .
All images to be selected must be present on screen.
You can also use this filter on an image with several layers . All
layers will appear in the drop-down lists used to select images.
These layers must have the same size .
 9. 2. 2. Accessing this Filter
You can find this filter through
Filters → Combine → Depth Merge 
9. 2.3. Options Figure 17. 162. “ Depth Merge ” filter options Source 1, Source 2
Defines the source images to use for the blending.
Depth map
Define the picture to use as transformation maps for the sources.
Overlap Creates soft transitions between images. Offset
This option shifts the merging limit, giving more or less
importance to an image against the other.
Scale 1, Scale 2
Same as above for Offset, but more sensitive and applied to each
map separately. When you scale to a lower value, it will affect
the map image's value, making it darker. So, black is more
dominant in the merge and you will see more of the image.
9.2.4. Using example
Maps are grayscale gradients created with the
Blend tool and modified with the
Curve tool .
Figure 17.163. Source images and their maps Source image 1 Source image 2 Map 1 Map 2
You can understand what's going on. Image-1 is treated by map-1: the red
square is masked and the yellow square remains visible. Image-2 is
treated by map-2: the red circle is masked and the green circle remains
visible. In total, the green circle and the yellow square stay visible.
Figure 17.164. Results No offset and no overlap .
The limit between both images is sharp and is situated
in the middle of the mask gradient.
Offset = 0.980 : the limit, sharp,
is shifted so that the image2 area is increased.
Overlap : the limit is blurred.
Scale 1
reduced to 0.056 : as with Offset, the limit is shifted. Image-1
area is increased.
9. Combine Filters 9.3. Film
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3. 4. Despeckle 3.4. Despeckle 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 4. Despeckle 3.4. 1. Overview
This filter is used to remove small defects due to dust, or scratches,
on a scanned image, and also moiré effects on image scanned from a
magazine. You should select isolated defects before applying this
filter, in order to avoid unwanted changes in other areas of your image.
The filter replaces each pixel with the median value of the pixels within
the specified radius.
 3. 4. 2. Activating the filter
You can find this filter through
Filters → Enhance → Despeckle .  3. 4.3. Options Figure 17. 23.  “ Despeckle ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview.  Median Adaptive
Adapts the radius to image or selection content by
analyzing the histogram of the region around the target
pixel. The adapted radius will always be equal to or
smaller than the specified radius.
Recursive
Repeats filter action which gets stronger.
Radius
Sets size of action window from 1 (3x3 pixels) to 20 (41x41). This
window moves over the image, and the color in it is smoothed, so
imperfections are removed.
Black level
Only include pixels brighter than the set value in the histogram ( -1-255).
White level
Only include pixels darker than the set value in the histogram ( 0-256).
3.3. Deinterlace 3.5. Destripe
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3. 5. Destripe 3.5. Destripe 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 5. Destripe 3.5. 1. Overview
It is used to remove vertical stripes caused by poor quality
scanners. It works by adding a pattern that will interfere with
the image, removing stripes if setting is good. This
“ negative ” pattern is calculated from vertical elements
of the image, so don't be surprised if you see stripes on the
preview of an image that has none. And if pattern
“ strength ” ; is too high, your image will be striped.
If, after a first pass, a stripe persists, rectangular-select it
and apply filter again (all other selection type may worsen the
result).
 3. 5. 2. Activating the filter
You can find this filter through
Filters → Enhance → Destripe .  3. 5.3. Options Figure 17. 24.  “ Destripe ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Create histogram
This “ histogram ” is a black and white image showing
the interference pattern more legibly.
Width
Slider and input box allow to set “ strength ” of
filter (2-100): more than 60 is rarely necessary and may create
artifacts.
3.4. Despeckle 3.6. NL Filter
 Report an error in Bugzilla  13. 10. Diffraction Patterns 13. 10. Diffraction Patterns 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 10. Diffraction Patterns 13. 10. 1. Overview Figure 17. 307. Two examples of diffraction patterns
This filter lets you make diffraction or wave interference textures.
You can change the Frequency, Contours and Sharp Edges for each of the
RGB channels. You can also set Brightness, Scattering and Polarization
of the texture. There is no automatic preview, so you must press the
preview button to update. On a slow system, this may take a bit of
time. Note that result doesn't depend on the initial image.
This is a very useful filter if you want to create intricate patterns.
It's perfect for making psychedelic, batik-like textures, or for
imitating patterns in stained glass (as in a church window).
It seems clear that the plugin works by simulating the physics of light
striking a grating. Unfortunately, the original authors never got around
to writing down the theory behind it, or explaining what the parameters
mean. The best approach, then, is just to twiddle things and see what
happens. Fortunately, almost anything you do seems to produce
interesting results.
 13. 10. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Pattern → Diffraction Patterns .  13. 10.3. Options Figure 17. 308. “ Diffraction Patterns ” filter options 13.9. CML Explorer 13. 11. Grid
 Report an error in Bugzilla  8. 3. Dilate 8.3. Dilate 8. Generic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 3. Dilate 8. 3. 1. Overview Figure 17. 156. Applying example for the Dilate filter Original image Filter “ Dilate ” applied
This filter widens and enhances dark areas of the active layer or
selection.
For every image pixel, it brings the pixel Value (luminosity) into line
with the lowest Value (the darkest) of the 8 neighbouring pixels (3x3
matrix). So, a dark pixel is added around dark areas. An isolated pixel
on a brighter background will be changed to a big “ pixel ” ,
composed of 9 pixels, and that will create some noise in the image.
In this image, the studied pixel has a red border and the studied
matrix has a green border. I hope you have understood how to go on
with the process and get a 3x3 pixel block: when the “ I ”
pixel is inside the green border, the studied pixel turns to black.
A larger dark area will dilate by one pixel in all directions :
The filter was applied 3 times .
On more complex images, dark areas are widened and enhanced the same,
and somewhat pixellated. Here, the filter was applied 3 times :
Of course, if background is darker than foreground, it will cover the
whole image.
 8. 3. 2. Activating the filter
This filter is found in the image window menu under
Filters → Generic → Dilate .  8. 3.3. Examples Figure 17.157. Dilate text Figure 17.158. Dilate neon effect 8.2. Convolution Matrix 8. 4. Erode
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12.3. Displace 12.3. Displace 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 3. Displace 12. 3. 1. Overview Figure 17. 248. Displacement examples Original image
The displacement map has four grey stripes with values of 210,
160, 110, and 60, respectively.
X displacement coefficient is 30. Vacated pixels are black. The
image areas corresponding to light gray (128) were displaced
19 and 8 pixels to the left. The image areas corresponding to dark
gray (127) were displaced 4 and 15 pixels to the right.
This filter uses a “ displace-map ”
to displace corresponding pixels of the image. This filter displaces
the content of the specified drawable ( active layer or selection) by
the amounts specified in X and Y Displacement multiplied by the
intensity of the corresponding pixel in the 'displace map' drawables.
Both X and Y displace maps should be gray-scale images and have the
same size as the drawable
. This filter allows interesting distortion effects.
 12. 3. 2. Activating the filter
You can find this filter through
Filters → Map → Displace  12. 3.3. Options Figure 17. 249. Displace filter options Preview
Uncheck this option if your processor is slow.
Displacement Mode
You can choose working in
Cartesian
coordinates, where pixels are displaced in X or Y direction, or
working in
Polar coordinates,
where the image is pinched and whirled by displacing pixels in
radial or tangent direction.
Please see the next sections for details about these options.
Edge Behavior
These options allows you to set displacement behaviour on active
layer or selection edges:
Wrap
With this option, what disappears on one edge reappears on
the opposite edge.
Smear
With this option, pixels vacated by displacement are
replaced with pixels stretched from the adjacent part of the
image.
Black
With this option, pixels vacated by displacement are
replaced with black.
12.3.3.1. Cartesian Displacement Mode Figure 17.250. Displace filter options (Cartesian) Displacement Mode: Cartesian
In both modes, direction and amount of displacement depend on the
intensity of the corresponding pixel in the displacement map.
The map, that should be a grayscale image, has 256 gray levels
(0-255), the (theoretical) average value is 127.5. The filter
displaces image pixels corresponding to pixels with values less than
127.5 (0 to 127) in map to one direction, corresponding to pixels with
values from 128 to 255 to the opposite direction.
X displacement, Y displacement
If the respective option is activated, image pixels
corresponding to pixels from 0 to 127 will be displaced to the
right for X, downwards for Y, image pixels corresponding to
pixels from 128 to 255 will be displaced to the left for X,
upwards for Y.
What you enter in input boxes, directly or by using arrow-head
buttons, is not the actual displacement. It's a coefficient used
in a
formula, which gives the pixel actual displacement according to
the scaled intensity
[18]
of the corresponding pixel in map, modulated by the coefficient
you enter. Introducing intensity into formula is important: this
allows progressive displacement by using a gradient map.
This value may be positive or negative. A negative displacement
is reverse of a positive one. The value varies in limits equal
to the double of image dimensions.
When you click on the drop-down list button , a list appears
where you can select a displacement map. To be present in this
list, an image must respect two conditions. First, this image
must be present on your screen when you call filter . Then, this
image must have the same dimensions as the original image. Most
often, it will be a duplicate original image, which is
transformed to grey scale and modified appropriately, with a
gradient. It may be possible to use RGB images, but color
luminosity is used making result prevision difficult. Map may be
different in horizontal and vertical directions.
12.3.3.2. Polar Displacement Mode Figure 17.251. Displace filter options (Polar) Displacement Mode: Polar Pinch
If this option is activated, the radial coordinates (i.e. the
distance to the image's midpoint, the “ pole ” )
of the pixels will be changed. Image pixels corresponding to
map pixels from 0 to 127 will be displaced outwards, image
pixels corresponding to pixels from 128 to 255 will be displaced
towards center.
For the values and the displacement map see above
( “ X/Y displacement ” ).
The displacement is independent from the polar distance, all
pixels are displaced by the same amount. So the image will not
only be stretched or compressed, but also distorted:
Image distortion by Pinch option
A 160x120 pixel image, plain white displacement map, and
displacement coefficient 20.0: this results in a 20 pixels
displacement towards center. This is a horizontal reduction in
size by 25%, vertical by 33%, and diagonal by 20%, so the image
will be distorted.
Whirl
If this option is activated, the angular coordinates of the
image pixels will be “ displaced ” by a map pixel
dependent amount. For a plain displacement map, the image will
be rotated , otherwise it will be whirled.
Image pixels corresponding to pixels from 0 to 127 in the map
will be displaced counterclockwise, image pixels corresponding
to pixels from 128 to 255 will be displaced clockwise.
For the values and the displacement map see above .
Note
For a plain, non neutral map, if displace mode “ Polar ”
is enabled, this filter works like
Whirl and Pinch .
12.3.4. Using gradient to bend a text Follow following steps: Start with opening your image.
Duplicate this image. Activate this duplicate and make it
gray-scaled
( Image → Mode → GrayScale ).
Fill it with the wanted gradient. This image will be your
Displacement map , with the dimensions of
original image.
Activate original image. Create a Text Layer
with your text. Set layer to image size: right-click on the layer
in layer dialog and, in the pop-menu, click on “ Layer to
image size ” . Note that letters in text layer lie on a
transparent background; now this filter doesn't displace
transparent pixels. Only letters will be displaced.
Activate the text layer. Open the Displace filter window. Set
parameters, particularly the displacement coefficient, according to
the result in Preview. Click OK .
This method also applies to standard layers: Tip
To get the wanted gradient, first draw a black to white gradient .
Then use the Curves tool to
modify the gradient curve.
12.3.5. Displacement Calculation
The following section will show you how to calculate the amount of
displacement, if you are interested in these details. If you don't want
to know it, you can safely omit this section.
The overview example showed the X displacement using a coefficient of
30.0: 19, 8, 4, or 15 pixels, depending on the grey level of the
displacement map's color.
Why just these amounts? That's easy:
If you check these equations, you will notice that the values they give
are not exactly the results we retained in the example
(using non-integers, that's not surprising). So, were the results
rounded to the nearest integer and then the pixels were
displaced by a whole-numbered amount? No. Every pixel is displaced
exactly by the calculated amount; a “ displacement by a fractional
amount ” is realized by interpolation. A closer look at the
example image will show it:
Figure 17.252. A closer look at the displacement example A small area zoomed in by 800 percent.
The displacement causes small (one pixel wide) areas of intermediate
colors at the edges of plain color areas. E.g., the black area (zoomed
in image) is caused by a displacement of -4.12, so the intermediate
color is 12% black and 88% gold.
So if you select a displacement coefficient of 30.01 instead of 30.00,
you will indeed get a different image, although you won't see the
difference, of course.
[18]
Scaled intensity = (intensity - 127.5) / 127.5;
see Section 12.3.5, “Displacement Calculation” .
12.2. Bump Map 12. 4. Fractal Trace
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7. 2. Difference of Gaussians 7.2. Difference of Gaussians 7. Edge-Detect Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 2. Difference of Gaussians 7. 2. 1. Overview Figure 17. 138.
Applying example for the “ Difference of Gaussians ” filter
Original image Filter “ Difference of Gaussians ” applied
This filter does edge detection using the
so-called “ Difference of Gaussians ”
algorithm, which works by performing two different Gaussian blurs on the
image, with a different blurring radius for each, and subtracting them
to yield the result. This algorithm is very widely used in artificial
vision (maybe in biological vision as well!), and is pretty fast because
there are very efficient methods for doing Gaussian blurs. The most
important parameters are the blurring radii for the two Gaussian blurs.
It is probably easiest to set them using the preview, but it may help to
know that increasing the smaller radius tends to give thicker-appearing
edges, and decreasing the larger radius tends to increase the
“ threshold ”
for recognizing something as an edge. In most cases you will get nicer
results if Radius 2 is smaller than Radius 1, but nothing prevents you
from reversing them, and in situations where you have a light figure on
the dark background, reversing them may actually improve the result.
 7. 2. 2. Activating the filter
You can find this filter through
Filters → Edge-Detect → Difference of Gaussians .  7. 2.3. Options Figure 17. 139.
Gaussian Difference filter options
Smoothing Parameters Radius 1 and Radius 2
are the blurring radii for the two Gaussian blurs. The only
constraints on them is that they cannot be equal, or else the
result will be a blank image. If you want to produce something
that looks like a sketch, in most cases setting
“ Radius 2 ” smaller than
“ Radius 1 ” will give better results.
Normalize
Checking this box causes the brightness range in the result to be
stretched as much as possible, increasing contrast. Note that in
the preview, only the part of the image that is shown is taken
into account, so with Normalize
checked the preview is not completely accurate. (It is accurate
except in terms of global contrast, though.)
Invert
Checking this box inverts the result, so that you see dark edges
on a white background, giving something that looks more like a
drawing.
7. Edge-Detect Filters 7. 3. Edge
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7. 3. Edge 7. 3. Edge 7. Edge-Detect Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 3. Edge 7. 3. 1. Overview Figure 17. 140. Applying example for the Edge filter Original image After applying the filter (Sobel option) Figure 17.141. Applying examples for the Edge filter After applying the filter ( Prewitt compass option) After applying the filter ( Gradient option) Figure 17.142. Applying example for the Edge filter After applying the filter ( Roberts option) After applying the filter ( Differential option) Figure 17.143. Applying example for the Edge filter After applying the filter ( Laplace option)  7. 3. 2. Activating the filter
You can find this filter through
Filters → Edge-Detect → Edge... .  7. 3. 3. Options Figure 17. 144. Edge filter options Algorithm Edge detector offers several detection methods: Sobel
Here, this method has no options and so is less interesting
than the specific Sobel.
Prewitt compass Result doesn't look different from Sobel. Gradient
Edges are thinner, less contrasted and more blurred than
Sobel.
Roberts No evident difference from Sobel. Differential Edges less bright. Laplace Less interesting than the specific one. Amount
A low value results in black, high-contrasted image with thin
edges. A high value results in thick edges with low contrast and
many colors in dark areas.
Wrap, Smear, Black
Where the edge detector will get adjoining pixels for its
calculations when it is working on the image boundaries. This
option will only have an effect on the boundaries of the result
(if any). Smear is the default and the best
choice.
7.2. Difference of Gaussians 7. 4. Laplace
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4. 4. Emboss 4.4. Emboss 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 4. Emboss 4. 4. 1. Overview Figure 17. 39. Applying example for the Emboss filter Original image Filter “ Emboss ” applied
This filter stamps and carves the active layer or selection, giving it
relief with bumps and hollows . Bright areas are raised and dark ones are
carved. You can vary the lighting.
You can use the filter only with RGB images. If your image is grayscale ,
it will be grayed out in the menu .
 4. 4. 2. Starting filter
You can find this filter through
Filters → Distorts → Emboss .  4. 4.3. Options Figure 17. 40. “ Emboss ” filter options Preview
All your setting changes will appear in the Preview without
affecting the image until you click on OK . Don't keep Preview checked if your computer
is too slow.
Function Bumpmap
Relief is smooth and colors are preserved.
Emboss
It turns your image to grayscale and relief is more marked,
looking like metal.
Azimuth
This is about lighting according to the points of the compass (0 -
360). If you suppose South is at the top of your image, then East
(0°) is on the left. Increasing value goes counter-clockwise.
Elevation
That's height from horizon (0 °), in principle up to zenith (90°),
but here up to the opposite horizon (180°).
Depth
Seems to be the distance of the light source . Light decreases when
value increases.
4.3. Curve Bend 4.5. Engrave
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4. 5. Engrave 4.5. Engrave 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 5. Engrave 4. 5. 1. Overview Figure 17. 41. Example for the “ Engrave ” filter Original image “ Engrave ” applied
This filter produces an engraving effect: the image is turned black and
white and some horizontal lines of varying height are drawn depending
on the value of underlying pixels. The resulting effect reminds of
engravings found in coins and old book illustrations.
Note
The “ Engrave ” filter operates only on floating selections
and layers with an alpha channel. If the active layer does not have an
alpha channel please add
it first.
 4.5. 2. Activating the filter
This filter is found in the image window menu under
Filters → Distorts → Engrave .  4. 5.3. Options Figure 17. 42. “ Engrave ” options Preview
The result of your settings will appear in the Preview without
affecting the image until you click on OK . Height
This option specifies the height of the engraving lines. The value
goes from 2 to 16.
Limit line width
If this option is enabled thin lines are not drawn on contiguous
color areas. See the figure below for an example of this option
result.
Figure 17.43. Example result of Limit line width option Original image Limit line width option enabled Limit line width option disabled 4.4. Emboss 4.6. Erase Every Other Row
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8. 4. Erode 8.4. Erode 8. Generic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 4. Erode 8. 4. 1. Overview Figure 17. 159. Erode noise Original image Filter “ Erode noise ” applied
This filter widens and enhances bright areas of the active layer or
selection.
For every image pixel, it brings the pixel Value (luminosity) into line
with the upper value (the brightest) of the 8 neighbouring pixels (3x3
matrix). So, a bright pixel is added around bright areas. An isolated
pixel on a brighter background will be deleted. A larger bright area
will dilate by one pixel in all directions .
On complex images, bright areas are widened and enhanced the same, and
somewhat pixellated.
On a solid background, this filter can delete noise:
Figure 17.160. “ Erode noise ” example  8. 4. 2. Activating the filter
This filter is found in the image window menu under
Filters → Generic → Erode .  8. 3. Dilate 9. Combine Filters
 Report an error in Bugzilla  8. 22. Color Exchange 8. 22. Color Exchange 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 22. 2. Activate the filter
This filter is found in the image window menu under
Colors → Map → Color Exchange .  8. 22.3. Options Figure 16.166. Option of the “ Two color exchange ” filter Preview
In this preview, a part of the Image is displayed . A selection
smaller than preview will be complete in preview. A bigger one
will be cut out to be adapted to the preview.
If you middle-click inside preview , the clicked pixel color
will be selected and will appear as From Color.
From color
In this section, you can choose the color to be used to select
pixels that will be concerned by color exchange.
Three sliders for RVB colors : If you
have clicked on preview, they are automatically positioned.
But you can change them . Each slider acts on color intensity.
Input boxes and arrowheads work the same. Result is
interactively displayed in the From swatch box.
Three sliders for thresholds , for each
color. The higher the threshold, the more pixels will be
concerned. Result is interactively displayed in Preview.
Lock Thresholds : This option locks threshold
sliders which will act all the same.
To color Three cursors allow to select the color
that pixels will have. Result is displayed in swatch box and in
preview. You can also click on the color dwell to get a color
selector.
8.21. Alien Map 8.23. Gradient Map  Report an error in Bugzilla  9. 3. Film 9.3. Film 9. Combine Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  9. 3. Film 9. 3. 1. Overview Figure 17. 165. Applying example for the Film filter Original image Filter “ Film ” applied
Film filter lets you merge several pictures into a photographic film
drawing.
Note
This filter does not invert colors, so it does not imitate negative
film like the ones used to produce prints. Instead you should think of
the result as an imitation of slide film or cinema film.
 9. 3. 2. Accessing this Filter
You can find this filter through
Filters → Combine → Film .  9. 3.3. Options 9.3.3.1. Selection Figure 17.166. “ Film ” filter options ( Selection) Film Fit height to images
Applies the height of original pictures to the resulting one.
Height
This option lets you define the height of the resulting
picture. If originals have different sizes, they will be
scaled to this size.
Color
By clicking on the color dwell you can define the color of
the film (around and between pictures).
Numbering Start index
Defines the beginning number which will be used for the
images.
Font Defines the font of digits. Color
By clicking on the color dwell, you can define the font
color of digits.
At top, At bottom Defines the position of the number. Image Selection Available images
Shows the pictures which can be used for merging. The
pictures are the ones already opened in GIMP.
On film Shows the pictures chosen to be merged. Add
This button allows the user to put an available image in the
“ On film ” section.
Remove
This button allows to bring a picture from “ On film
” to “ Available images ” . After that,
the picture will not be used anymore in the resulting
document.
9.3.3.2. Advanced Figure 17.167. “ Film ” filter options ( Advanced) Image height
Defines the height of each pictures in the resulting image.
Image spacing
Defines the space between the pictures as they will be
inserted in the future image.
Hole offset
Defines the hole position from image border.
Hole width
Defines the width of the holes in the resulting image.
Hole height
Defines the height of the holes in the resulting image.
Hole spacing Defines the space between holes Number height
Defines the height of the index number, proportionally to
the height of the picture.
9.2. Depth Merge 10. Artistic Filters
 Report an error in Bugzilla  8. 35. Filter Pack 8.35. Filter Pack 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 35. 2. Activate the filter
You can find this filter in the image window menu under
Colors → Filter Pack .  8. 35.3. Options Figure 16.190. All the options for filter “ Filter Pack ” Original and Current previews
Two previews display respectively before treatment and after
treatment images.
Show
Sets what you want to preview:
Entire image Selection only :
if a selection exists (default is the whole image).
Selection in context :
the selection within the image.
Windows You can choose between: Hue
makes one preview for each of the three primary colors and the
three complementary colors of the RGB color model. By clicking
successively on a color, you add to this color into the
affected range, according to Roughness. To subtract color,
click on the opposite color, the complementary color.
Figure 16.191.
Hue option of the “ Filterpack ” filter
Saturation : Three previews for more or
less saturation.
Figure 16.192.
The saturation option of the “ Filterpack ”
filter
Value : Three previews for more or less
luminosity.
Figure 16.193.
Value option of the “ Filterpack ” filter
Advanced : developed later.
Affected range
Allows you to set which brightness you want to work with .
Shadows : dark tones. Midtones Highlights : bright tones
Select pixels by
Determines what HSV channel the selected range will affect. You
can choose between:
Hue Saturation Value Roughness
This slider sets how image will change when you click on a
window: taking a short step or a large one (0 - 1).
Advanced Options Figure 16.194.
Advanced options of the “ Filterpack ” filter
These advanced options let you work more precisely on the changes
applied to the image and on the preview size.
Preview Size
Something like a zoom on previews. Normal size is 80.
Tip
In spite of Preview Size option, this size is often too
small. You can compensate this by working on an enlarged
selection, for instance a face on a photo. Then, you
invert selection to work on the other part of the image.
Affected range
Here, you can set the tone range that the filter will
affect.
The curve in this window represents the importance of the
changes applied to the image . The aspect of this curve
depends on the Affected range you have selected: Shadows,
Midtons or Highlights. You can set the curve amplitude by
using the Roughness
slider in the main window of the filter.
By using the available controls (slider and triangles),
you can precisely set the form of this action curve.
8.34. Color to Alpha 8.36. Hot
 Report an error in Bugzilla  13. 6. Flame 13.6. Flame 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 6. Flame 13. 6. 1. Overview Figure 17. 288. Example of a rendered Flame Filter “ Flame ” applied
With the Flame filter, you can create stunning, randomly
generated fractal patterns. You can't control the fractals as
you can with the IFS
Fractal filter, but you can steer the
random generator in a certain direction, and choose from
variations of a theme you like.
Warning
Unfortunately it turned out, that this filter is not working properly
for large images. Even more unfortunate is, that its developer is
currently not undertaking any actions with that plug-in at all, so
there seems no quick fix in sight. Although we can't give you the exact
numbers, the plug-in worked in a quick test for a 1024x768 pixel
image, but didn't do it for a 2500x2500 pixel image.
Note
This plug-in was given to GIMP by Scott Draves in 1997. He also holds
the copyright for the plug-in. An descriptive page for the plug-in,
provided by the author can be found in the internet
[ PLUGIN-FLAMES ] .
 13.6. 2. Activating the filter
You can find this filter through
Filters → Render → Nature → Flame .  13. 6.3. Options Figure 17. 289. “ Flame ” filter options
In the main window, you can set Rendering and Camera
parameters. The first three parameters in the Render display are
Brightness, Contrast and Gamma. The result of these options is
visible in the Preview window, but it's generally better to
stick to the default values, and correct the rendered image
later with Image/Colors.
The other three parameters affect the rendering process and
don't show in the preview window. Sample Density, which controls
the resolution of the rendered pattern , is the most important of
these. The Camera parameters allow
you to zoom and offset the flame pattern, until you're happy
with what you see in the preview window. Flame also offers the
possibility to store and load your favorite patterns.
Edit
Pressing this button brings up the Edit dialog:
Figure 17.290. The Edit Flame dialog
The dialog shows nine different windows. The pattern displayed in
the center is the current pattern, and the eight windows
surrounding it are random variations of that pattern. Clicking on
the central image creates eight new variations, which can be
adjusted with the Speed control. You select a variation by
clicking on it, and it instantly replaces the image in the middle.
To pick a certain character or theme for the variations, you can
choose from nine different themes in the
Variations menu. You can also use
Randomize , which replaces the current
pattern with a new random pattern.
Open
This button brings up a file selector that allows you to
open a previously saved Flame settings file.
Save
This button brings up a file save dialog that allows you
to save the current settings for the plug-in, so that you
can recreate them later.
Rendering Brightness
Controls the brightness of the flame object.
Contrast
Controls the contrast between brighter and dimmer parts of
the flame.
Gamma
Sets a gamma correction for parts with intermediate
brightness.
Sample density
Controls the resolution of the rendered pattern . ( Does
not have any effect on the preview.) A high sample
density results in soft and smooth
rendering (like a spider's web), whereas low density
rendering resembles spray or particle clouds.
Spatial oversample
What does this do?
Spatial filter radius
What does this do?
Colormap
This menu gives you several options to set the color blend
in the flame pattern:
The current gradient as shown in the Toolbox.
A number of preset colormaps.
The colors from images that are presently open in
GIMP .
Camera Zoom
Allows you to zoom the flame in or out.
X, Y
Allows you to move the flame around in the image area.
13.5. Solid Noise 13. 7. IFS Fractal
 Report an error in Bugzilla 
5. 3. Lens Flare 5.3. Lens Flare 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 3. Lens Flare 5. 3. 1. Overview Figure 17. 97. Example for the Lens Flare filter Original image Filter “ Lens Flare ” applied
This filter gives the impression that sun hit the objective when taking
a shot. You can locate the reflection with a reticule you can move, but
you have not the possibilities that the
Gradient Flare filter offers.
 5. 3. 2. Activate the filter
You can find this filter in the image menu menu through
Filters → Light and Shadow → Lens Flare .  5. 3.3. Options Figure 17. 98.  “ Lens Flare ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Center of Flare Effect
You can set X and Y
(pixels) coordinates of glint using the input box or by clicking
into the preview. The coordinate origin is at the upper left
corner.
Show position
When this option is checked , a reticule appears in preview and you
can move it with the mouse pointer to locate the center of Lens
Flare effect.
Tip
The mouse cursor, which looks like a cross when it moves over
the preview, lets you locate the filter effect even without the
reticule.
5.2. Gradient Flare 5. 4. Lighting Effects
 Report an error in Bugzilla  12.4. Fractal Trace 12. 4. Fractal Trace 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 4. Fractal Trace 12. 4. 1. Overview Figure 17. 253. Fractal Trace Original image Filter “ Fractal Trace ” applied
This filter transforms the image with the Mandelbrot fractal: it maps
the image to the fractal.
 12. 4. 2. Activate the filter
This filter is found in the image window menu under
Filters → Map → Fractal trace .  12. 4.3. Options Figure 17. 254. “ Fractal trace ” filter options Mandelbrot parameters X1, X2, Y1, Y2, Depth
These parameters are similar to X/YMIN, X/YMAX and ITER
parameters of the
Fractal Explorer
filter. They allow you to vary fractal spreading and detail
depth.
Outside Type
Mapping image to fractal may reveal empty areas. You can select
to fill them with Black ,
White , Transparency or
make what disappears on one side reappear on the opposite side
with Wrap option.
12.3. Displace 12.5. Illusion
 Report an error in Bugzilla  13. 17. Fractal Explorer 13. 17. Fractal Explorer 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 17. Fractal Explorer 13. 17. 1. Overview Figure 17. 324. Example for the Fractal Explorer filter
Filter “ Fractal Explorer ” applied
With this filter , you can create fractals and multicolored pictures
verging to chaos. Unlike the
IFS Fractal filter, with which you
can fix the fractal structure precisely, this filter lets you perform
fractals simply.
 13. 17. 2. Starting filter
You can find this filter through
Filters → Render → Fractal Explorer .  13. 17.3. Options Figure 17. 325. “ Fractal Explorer ” filter options
The Fractal Explorer window contains two panes: on the left there is the
Preview pane with a Zoom feature, on the right you find the main options
organized in tabs: Parameters, Colors, and Fractals.
13.17.3.1. Preview Realtime preview
Uncheck the Realtime preview only if your
computer is slow. In this case, you can update preview by
clicking on the Redraw preview button.
By clicking-dragging mouse pointer on preview, you can draw a
rectangle delimiting an area which will be zoomed.
Zoom
You have there some options to zoom in or zoom out. The
Undo allows you to return to previous
state, before zooming. The Redo allows
you to reestablish the zoom you had undone, without having to
re-create it with the Zoom In or
Zoom Out buttons.
13.17.3.2. Parameters Figure 17.326.
“ Fractal Explorer ” filter options (Parameters)
This tab contains some options to set fractal calculation and select
fractal type.
Fractal Parameters
Here, you have sliders and input boxes to set fractal
spreading, repetition and aspect.
Left, Right, Top, Bottom
You can set fractal spreading between a minimum and a
maximum, in the horizontal and/or vertical directions.
Values are from -3.0 to 3.0.
Iterations
With this parameter, you can set fractal iteration,
repetition and so detail. Values are from 0.0 to 1000.0
CX, CY
With these parameters, you can change fractal aspect, in
the horizontal (X) and/or vertical (Y) directions, except
for Mandelbrot and Sierpinski types.
Open, Reset, Save
With these three buttons, you can save your work
with all its parameters, open a previously saved
fractal, or return to the initial state before all
modifications.
Fractal Type
You can choose what fractal type will be, for instance
Mandelbrot , Julia ,
Barnsley or
Sierpinski .
13.17.3.3. Colors Figure 17.327.
“ Fractal Explorer ” filter options (Colors)
This tab contains options for fractal color setting. Number of Colors Number of colors
This slider and its input boxes allow you to set the number of
colors for the fractal, between 2 and 8192. A palette of these
colors is displayed at the bottom of the tab. Actually, that's a
gradient between colors in fractal: you can change colors with
“ Color Density ” and “ Color Function ”
options. Fractal colors don't depend on colors of the original
image (you can use a white image for fractals as well).
Use loglog smoothing
If this option is checked , the band effect is smoothed.
Figure 17.328. Loglog smoothing example Color density Red, Green, Blue
These three sliders and their text-boxes let you set the color
intensity in the three color channels. Values vary from 0.0 to
1.0 .
Color Function
For the Red , Green and
Blue color channels, you can select how color
will be treated:
Sine
Color variations will be modulated according to the sine
function.
Cosine
Color densities will vary according to cosine function.
None Color densities will vary linearly. Inversion
If you check this option , function values will be inverted.
Color Mode
These options allow you to set where color values must be taken
from.
As specified above
Color values will be taken from the Color
Density options.
Apply active gradient to final image
Used colors will be that of active gradient. You should be able
to select another gradient by clicking on the gradient source
button.
13.17.3.4. Fractals Figure 17.329.
“ Fractal Explorer ” filter options (Fractals)
This tab contains a big list of fractals with their parameters, that
you can use as a model: only click on the wanted one.
The Refresh allows you to update the list if
you have saved your work, without needing to re-start
GIMP . You can delete the selected fractal from the
list by clicking on the Delete .
13.16. Circuit 13.18. Gfig
 Report an error in Bugzilla 
2. 3. Gaussian Blur 2.3. Gaussian Blur 2. Blur Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 3. Gaussian Blur 2. 3. 1. Overview Figure 17. 9. Example for the “ Gaussian Blur ” filter Original Blur applied
The IIR Gaussian Blur plug-in acts on each pixel of the active layer or
selection , setting its Value to the average of all pixel Values present
in a radius defined in the dialog. A higher Value will produce a higher
amount of blur. The blur can be set to act in one direction more than
the other by clicking the Chain Button so that it is broken, and
altering the radius. GIMP supports two implementations of Gaussian Blur:
IIR G.B. and RLE G.B. They both produce the same results, but each one
can be faster in some cases.
 2.3. 2. Activate the filter
You can find this filter in the image menu under
Filters → Blur → Gaussian Blur  2. 3.3. Options Figure 17. 10. “ Gaussian ” filter parameters settings Blur Radius
Here you can set the blur intensity . By altering the ratio of
horizontal to vertical blur, you can give the effect of a motion
blur. You can choose the unit with the drop list.
Blur Method IIR
IIR stands for “ infinite impulse response ” . This
blur works best for large radius values and for images which
are not computer generated.
RLE
RLE stands for “ run-length encoding ” . RLE
Gaussian Blur is best used on computer-generated images or
those with large areas of constant intensity.
2.2. Blur 2.4. Selective Gaussian Blur  Report an error in Bugzilla  13. 18. Gfig 13.18. Gfig 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 18. Gfig 13. 18. 1. Overview Figure 17. 330. The same image, before and after using Gfig Original image Filter “ Gfig ” applied
This filter is a tool: You can create geometrical figures to add them to
the image. It is very complex. I hope this paper will help you.
When using this filter, elements inserted in the image will be placed in
a new layer. So the image will not be modified, all modifications
occurring in this layer.
 13. 18. 2. Starting filter
You can find this filter through
Filters → Render → Gfig  13. 18.3. Options Figure 17. 331. “ Gfig ” filter options
The Preview (with a horizontal and a vertical ruler) on the left of the
main window actually is your working area where you are adding your
figures.
You can add and modify figures using the Gfig tools
( Gfig tool bar )
and using the appropriate options
( Gfig main window ).
13.18.3.1. The Gfig tool bar
At the top of dialog, you can find a set of icons which represents the
functions of this filter. Help pop-ups are explicit.
Functions for object drawing
On the left part of tool bar, you can find some functions for object
drawing. You enable them by clicking on the corresponding icon. You
can create the following objects (note that Control
points are created at the same time as object ):
Create line
With this tool, you can draw lines. Click on Preview to mark
start point, then drag mouse pointer to the end point.
Create rectangle
With this tool, you can draw rectangles. Click on Preview to
mark start point, then drag mouse pointer to create the
rectangle.
Create circle
With this tool, you can draw circles. Click on Preview to mark
center, then drag mouse pointer to the wanted radius.
Create ellipse
With this tool, you can draw ellipses. Click on Preview to mark
center, then drag mouse pointer to get the wanted size and form.
Create arc
With this tool, you can draw circle arcs. Click on Preview to
set start point . Click again to set another arc point. Without
releasing mouse button, drag pointer; when you release mouse
button, the arc end point is placed and an arc encompassing
these three points is drawn.
Create regular polygon
With this tool, you can create a regular polygon. Start with
setting side number in Tool Options at the
right of Preview. Then click on Preview to place center and,
without releasing mouse button, drag pointer to get the wanted
size and orientation.
Create star
With this tool, you can create a star. Start with setting side
number (spikes) in Tool Options at the
right of Preview. Then click on Preview to place center and,
without releasing mouse button, drag pointer to get the wanted
size and orientation.
Create spiral
With this tool, you can create a spiral. Start with setting
spire number (sides) and spire orientation in Tool
Options at the right of Preview. Then click on
Preview to place center and, without releasing mouse button,
drag pointer to get the wanted size .
Create bezier curve
With this tool, you can create Bézier curves. Click on
Preview to set start point and the other points: the curve will
be created between these points. To end point creation press
Shift key when creating last point.
Functions for object management
In the middle of tool bar, you can find tools to manage objects:
Move an object
With this tool, you can move the active object. To enable an
object, click on a control point created at the same time as the
object.
Move a single point
With this tool, you can click-and-drag one of the control points
created at the same time as object . Each of these points moves
the object in a different way.
Copy an object
With this tool, you can duplicate an object. Click on an object
control point and drag it to the wanted place.
Delete an object Click on an object control point to delete it. Select an object
With this tool, you can select an object to active it. Simply
click on one of its control points.
Functions for object organisation
At the right of tool bar, you can find tools for object
superimposing (you can also get them by clicking on the drop-down
list button if they are not visible). You have:
Up (Raise selected object), Down (Lower selected object)
With this tool, you can push the selected object one level up or
down.
Top, Bottom Self explanatory. Functions for object display Back, Forward
These functions allow you to jump from one object to another.
Only this object is displayed.
Show all objects
This function shows all objects again, after using both previous
functions.
Note
If your window is too small to show all icons, the tool bar provides a
drop-down list which offers you the missing functions.
13.18.3.2. The Gfig main window Object Details
The XY position shows the position of your
pointer.
Tool Options
If the selected tool provides some options (like number of
sides), you can change them here.
Stroke
If this option is checked , the object will be drawn. Two
buttons are available, to select color and brush type.
Changes to color or brush apply to existing objects too.
Fill
With help of this drop-down list, you can decide whether
and how the object will be filled, with a color, a pattern
or a gradient.
Show grid
If this option is checked , a grid is applied on Preview to
make object positioning easier.
Snap to grid
If this option is checked , objects will align to the grid.
Show image
When this option is checked , the current image is displayed in
Preview (working area).
13.17. Fractal Explorer 13. 19. Lava
 Report an error in Bugzilla  5. 2. Gradient Flare 5. 2. Gradient Flare 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 2. Gradient Flare 5. 2. 1. Overview Figure 17. 90. Example for the Gradient Flare filter Original image Filter “ Gradient Flare ” applied
Gradient Flare effect reminds the effect you get when you take a
photograph of a blinding light source, with a halo and radiations around
the source. The Gradient Flare image has three components:
Glow which is the big central fireball,
Rays and Second Flares
 5. 2. 2. Activating the filter
This filter is found in the image window menu under
Filters → Light and Shadow → Gradient Flare  5. 2.3. Options
The Settings tab allows you to set manually the
parameters while the Selector tab let you choose
presets in a list.
Preview
When Auto update preview is checked,
parameter setting results are interactively displayed in preview
without modifying the image until you click on
OK button.
5.2. 3.1. Settings Figure 17. 91. “ Gradient Flare ” filter options ( Settings) Center
You can set X and Y (pixels) coordinates of glint using the
input box or by clicking into the preview. The coordinate origin
is at the upper left corner.
Parameters Radius
The radius of the effect. The slider limits the range of
possible values, but using the input box you can enter
greater values.
Rotation Turn the effect. Hue rotation Change the tint (color) of the effect. Vector angle Turn the Second flares. Vector length Vary the distance applied for the Second flares. Adaptive supersampling
Settings of the anti-aliasing following parameters like Depth
and Threshold. (See also
Supersampling .)
5.2.3.2. Selector Figure 17.92. “ Gradient Flare ” filter options ( Selector)
The Selector tab allows you to select a Gradient Flare pattern, to
change it and save it.
New
When you click on this button, you create a new Gradient Flare
pattern. Give it a name of your choice.
Edit
This button brings up the
Gradient Flare
Editor (see below).
Copy
This button allows you to duplicate selected Gradient Flare
pattern. You can edit the copy without altering the original.
Delete
This button deletes the selected Gradient Flare pattern.
5.2.4. Gradient Flare Editor
The Gradient Flare Editor is also organized in tabs:
5.2.4.1. General Figure 17.93. “ Gradient Flare Editor ” options ( General) Glow Paint Options Opacity
Slider and input box allows you to reduce glow opacity
(0-100).
Paint mode You can choose between four modes: Normal
In this mode, the glow covers the image without
taking into account what is beneath.
Addition
Pixel RGB values of glow are added to RGB values of
the corresponding pixels in the image. Colors get
lighter and white areas may appear.
Overlay
Light/Dark areas of glow enhance corresponding
light/dark areas of image.
Screen
Dark areas of image are enlightened by corresponding
light areas of glow. Imagine two slides projected
onto the same screen.
Rays Paint Options
Options are the same as for
Glow Paint Options .
Second Flare Paint Options
Options are the same as for
Glow Paint Options .
5.2.4.2. Glow Figure 17.94. “ Gradient Flare Editor ” options ( Glow) Gradients
By clicking on the rectangular buttons, you can develop a long
list of gradients. “ % ” gradients belong to the
Editor.
Radial gradient
The selected gradient is drawn radially, from center to
edge.
Angular gradient
The selected gradient develops around center,
counter-clockwise, starting from three o'clock if the
Rotation parameter is set to 0.
Radial and angular gradients are combined according to the
Multiply mode: light areas are enhanced and colors are
mixed according to CMYK color system (that of your
printer).
Angular size gradient
This is a gradient of radius size which develops
angularly. Radius is controlled according to gradient
Luminosity: if luminosity is zero (black), the radius is
0%. If luminosity is 100% (white), the radius is also
100%.
Parameters Size (%)
Sets size of glow in percent (0-200).
Rotation
Sets the origin of the angular gradient (-180 +180).
Hue rotation
Sets glow color, according to the HSV color circle (-180
+180). (Cf. The
triangle color selector .)
5.2.4.3. Rays Figure 17.95. “ Gradient Flare Editor ” options ( Rays) Gradients
The options are the same as for
Glow .
Parameters
The first three options are the same as in
Glow .
Two are new:
# of Spikes
This option determines the number of spikes (1-300) but
also their texture.
Spike thickness
When spikes get wider (1-100), they look like flower
petals.
5.2.4.4. Second Flares Figure 17.96.
“ Gradient Flare Editor ” options ( Second Flares)
Gradients
The options are the same as for
Glow .
Parameters
Options are the same as in
Glow .
Shape of Second Flares
Second flares, these satellites of the main flare, may have
two shapes: Circle and
Polygon . You can set the
Number polygon sides. The option
accepts 1 side (!), not 2.
Random seed
The random generator will use this value as a seed to generate
random numbers. You can use the same value to repeat the same
“ random ” sequence several times.
Randomize
When you click on this button, you produce a random seed that
will be used by the random generator. It is each time different.
5. Light and Shadow Filters 5. 3. Lens Flare
 Report an error in Bugzilla  10. 6. GIMPressionist 10.6. GIMPressionist 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 6. GIMPressionist 10. 6. 1. Overview Figure 17. 179. Example for the “ GIMPressionist ” filter Original image Filter “ GIMPressionist ” applied
The GIMPressionist filter is the king of Artistic filters. It can do
what Cubism and
Apply Canvas do and much
more. It gives your image the look of a painting. All is going as if
your image was painted again on a paper and with a brush you'd have
chosen. It works on the active layer or selection.
 10. 6. 2. Activating the filter
You can find this filter via the image menu through
Filters → Artistic → GIMPressionist .  10. 6.3. Options Figure 17. 180. GIMPressionist options
The dialog window consists of a small Preview area on the left , which is
always visible, and a huge amount of GIMPressionist options organized in
tabs.
10.6.3.1. Preview
All your setting changes will appear in the Preview without affecting
the image until you click on OK . The
Update button refreshes the preview window (it
is not automatic, GIMPressionist has so much work to do!), and the
Reset button reverts to the original image.
10.6.3.2. Presets tab Figure 17.181. “ Presets ” tab options
GIMPressionist has a lot of parameters. When combined, they
give an astronomical number of possibilities. So, it is important,
when an interesting preset has been found, to save it and also to
send it to the plugin author if exceptional. Per contra, the
intricacy of all these parameters makes difficult understanding
and foreseeing how each one works.
Presets options Save Current
Save current parameters.
You can give a name in the input box on the left and a short
description in the dialog that appear.
Apply
Load the parameters of the selected preset in the list.
Delete
Delete the selected preset. You can delete only the presets you
have created.
Refresh Update the preset list. 10.6.3.3. Paper tab Figure 17.182. “ Paper ” tab options
This tab concerns the texture of the canvas your image will be painted
on. You have a list of textures and a Preview for
the selected texture. A description is displayed on the right for
every texture when selected.
Paper options Invert
Inverts the paper texture: what was a hollow turns to a bump
and vice-versa.
Overlay
Apply the paper as it, without embossing it. It looks like
if a transparent paper has been overlayed on the image.
Scale
Specifies the scale of the texture (in % of the original
file): controls the graininess of the texture.
Relief
Specifies the amount of embossing to apply (3-150).
10.6.3.4. Brush tab Figure 17.183. “ Brush ” tab options “ Brush ” is a general term for any material used to paint.
A list of brushes is available with a Preview for
the selected one.
Brush options Gamma
Changes the gamma (luminosity) of the selected brush. The
gamma correction brightens or darkens midtones.
Select
You can also use a brush pattern you have created by
selecting its image (arrow button on the Select line). This
image must be on your screen before you launch the filter to
be taken in account. Of course, don't use big images.
If your image has several layers, they also will be
displayed in the Select list and can be used as a brush.
When selected, the layer appears in the brush preview and
the normal brush is deselected.
The Save as
button allows you to save the selected brush.
Aspect ratio
Specifies the brush proportions, height (0 -1) and width (0
+1).
Relief
Specifies the amount of paint used for each stroke. This may
evoke painting with a palette knife.
10.6.3.5. Orientation tab Figure 17.184. “ Orientation ” tab options
This tab allows to set the orientation of the brush strokes. A painter
is not obliged to go over with the same paintbrush angle. To perform
some effects, he can vary their orientation.
Orientation options Directions
With this option, you can set how many times the brush will pass
through a same place, with each time a different direction,
resulting in a more and more thick paint.
Start angle
Specifies the general direction of the strokes, the angle that
the angle range will start from. Directions are often chosen to
give some movement to the image.
Angle span
Specifies the angle, the sector, of the stroke “ fan ” .
Orientation Specifies the direction of the brush strokes. Value
Let the value (luminosity) of the region determine the direction of the stroke.
Radius
The distance from the center of the image determines
the direction of the stroke.
Random Select a random direction for each stroke. Radial
Let the direction from the center determine the direction
of the stroke.
Flowing
Not a direction question here: the strokes follow a
“ flowing ” pattern.
Hue
Let the hue of the region determine the direction of the
stroke.
Adaptive
The brush direction that matches the original image the
closest is selected.
Manual
The Edit button opens the
Edit
orientation Map dialog that allows you to set the
directions manually.
10.6.3.6. Size tab Figure 17.185. “ Size ” tab options
This tab allows you to set the number of brush sizes that will be used
to paint, the limits of variation of these sizes and the criterion
used to determine them.
Size options
You can specify how many brush sizes are to be used and their sizes.
Sizes The number of brush sizes to use. Minimum size, Maximum size
The brush sizes are between these two values. The greater the
size, the greater the length and width of strokes.
Size
You have there options to specify how the size of strokes
will be determined.
Value
Let the value (luminosity) of the region determine the size of the stroke.
Radius
The distance from the center of the image determines the
size of the stroke.
Random Select a random size for each stroke. Radial
Let the direction from the center determine the size of
the stroke.
Flowing
Not a length question here: the strokes follow a
“ flowing ” pattern.
Hue
Let the hue of the region determine the size of the
stroke.
Adaptive
The brush size that matches the original image the closest
is selected.
Manual
The Edit button opens the
Size Map
Editor . That allows you to specify the size of
strokes by yourself.
10.6.3.7. Placement tab Figure 17.186. “ Placement ” tab options
In this tab you can set how strokes will be distributed.
Placement options Placement
In the preview of the Orientation Map Editor, all small
arrows look like a flow around objects. Inside this flow,
strokes may be placed in two different ways:
Randomly
Places strokes randomly. This produces a more realistic
paint.
Evenly distributed
Strokes are evenly distributed across the image.
Stroke density
The greater the density the closer the strokes. With a low
density, the paper or background may be visible in unstroke
areas.
Centered Focus brush strokes around center. 10.6.3.8. Color tab Figure 17.187. “ Color ” tab options
In this tab, you can set what the stroke color will be.
Color options Color
You can set the stroke color in two ways:
Average under brush
Stroke color is computed from the average of all
pixels under the brush.
Center of brush
Samples the color from the pixel in the center of the
brush.
Color noise
This slider, and its input box, allow you to introduce noise
in the stroke color, that will look less homogeneous.
10.6.3.9. General tab Figure 17.188. “ General ” tab options
In this tab you can set what will be the background and the relief
of brush strokes.
General options Background Keep original
The original image will be used as a background.
From paper
Copy the texture of the selected paper as a background.
Solid
By clicking on the color dwell you can select a solid
colored background.
Transparent
Use a transparent background. Only the painted strokes
will be visible. This option is available only if your
image has an alpha channel .
Paint edges
If it is disabled, a thin border will not be painted around
the outside border of the image.
Tileable
If checked, the resulting image will be seamlessly tileable.
The right side will match the left side and the top will
match the bottom. This is interesting if your image will be
repeatedly used in a Web background.
Drop shadow Add a shadow effect to each brush stroke. Edge darken
How much to darken the edges of each brush stroke. This
increases paint relief or thickness.
Shadow darken How much to darken the brush shadow. Shadow depth
How far apart from the object the drop shadow should be.
Shadow blur How much to blur the drop shadow. Deviation threshold
A bail-out value for adaptive selections of brush size.
10.6.4. Orientation Map Editor 10.6.4.1. Overview
The Orientation- map editor is an annexe of the
GIMPressionist filter. You
can get to it by clicking on the Edit button in
the
Orientation
tab. With this editor, you can set the direction that brush strokes
given by filter will have.
10.6. 4.2. Options Figure 17.189.
Options of the “ Orientation-map Editor ” dialog
You can place one or several vectors. You can set their direction and
their strength. They will act on the corresponding area of the image.
Vectors
In the left windows (Vectors) you can manage your vectors. By
default, a vector is at center. Vectors are red when they are
active, and grey when they are not with a white point at tip.
By clicking on the Add button, you add
a vector at center of the window, whereas clicking with the
mouse Middle Button puts it
where you click. Clicking with the mouse
Left Button displaces the
selected vector to the clicked point.
When clicking with the mouse
Right Button , the selected
vector points to where you have clicked.
Clicking on & lt; & lt; and
& gt; & gt; buttons displaces focus from a
vector to another.
The Delete button allows you to delete
the selected vector.
Tip
With the scroll bar on the right of the Vectors panel, you can
set the image brightness. This can be very useful if the image
is very dark/bright and you can't see vectors well.
Preview
This Preview gives you an idea of the action of the various
vectors. The slider on the right border lets you change the
luminosity of this preview.
Type
You have there some types to arrange the brush strokes within the
selected vector domain. Describing them is difficult, but you can
see the result in the Preview.
Voronoi
A Voronoi's diagram consists in
partitioning a plane with n master points into n polygons
where each polygon has only one of these n master points and
where any given other point of the polygon is closer to the
master point than to any other. So each polygon limit is
midway between two master point. Here is an example of a
Voronoi's diagram:
Here, when this option is checked , only the vector closest to
a given point of the image influences this point.
Angle
Direction of the selected vector.
This slider has the same action as right-clicking (see above).
Angle offset
This slider allows you to change the angle of
all vectors.
Strength
This slider acts on the influence domain of the selected vector.
This influence lowers with distance. Strength is showed with the
vector length.
Strength exp.
This slider acts on the length of all
vectors, and so changes the strength of all brush strokes.
10.6.5. Size Map Editor 10.6.5.1. Overview
The Size- map editor is an annexe of the
GIMPressionist filter. You
can get to it by clicking on the Edit button in
the Size tab. With
this editor, you can set the size that brush strokes given by filter
will have.
10.6. 5.2. Options Figure 17.190. Size-map editor options
You can place one or several vectors. You can set their strength. They
will act on the corresponding area of the image.
Smvectors
In this window you can place your vectors. By clicking on
the Add button, you add a vector at the
center of the window, whereas clicking with the mouse
Middle Button puts it where you
click. Vectors are red when selected, and gray when they are not,
with a white point at tip.
Clicking with the mouse
Left Button displaces the selected
vector to the clicked point.
Clicking on the mouse
Right Button , has no evident
action.
Clicking on & lt; & lt; and
& gt; & gt; buttons displaces focus from a
vector to another.
The Kill button allows you to delete
the selected vector.
Tip
With the scroll bar on the right of the Vectors panel, you can
set the image brightness. This can be very useful if the image
is very dark/bright and you can't see vectors well.
Preview
This Preview gives you an idea of the action of the different
vectors. The size of squares represent the size of the brushes and
their strength.
Size
Change the size of the brush strokes in the selected vector
domain.
Strength
This slider acts on the influence domain of the selected vector.
This influence lowers with distance.
Strength exp. Change the exponent of the stroke. Voronoi
See Orientation Map
Editor for an explanation.
10.5. Cubism 10.7. Oilify
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5. 11. Glass Tile 5.11. Glass Tile 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 11. Glass Tile 5. 11. 1. Overview Figure 17. 124.
The same image, before and after applying glass tile effect.
Original image Filter “ Glass Tile ” applied
After applying this filter, the active layer or selection is rendered
as through a glass brick wall.
 5.11. 2. Activate the filter
You can find this filter through
Filters → Light and Shadow → Glass Tile  5. 11.3. Options Figure 17. 125.  “ Glass Tile ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Tile width, Tile length Sets tile width and length (10-50 pixels).
By default, width and height are linked, indicated by the chain
symbol next to the input boxes. If you want to set width and
height separately, click on that chain symbol to unlink them.
5.10. Apply Lens 6. Noise Filters
 Report an error in Bugzilla  8. 23. Gradient Map 8.23. Gradient Map 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 23. Gradient Map 8.23. 1. Overview Figure 16.167. Example of gradient map
Example of Gradient Mapping. Top: Original image. Middle: a
gradient. Bottom: result of applying the gradient to the
original image with the Gradient Map filter.
This filter uses the current gradient, as shown in the
Brush/Pattern/Gradient area of the Toolbox, to recolor the active
layer or selection of the image to which the filter is applied. To
use it, first choose a gradient from the
Gradients Dialog .
Then select the part of the image you want to alter, and activate the
filter. The filter runs automatically, without
showing any dialog or requiring any further input. It uses image
color intensities (0 - 255), mapping the darkest pixels to
the left end color from the gradient , and the lightest pixels to
the right end color from the gradient . Intermediate values are set
to the corresponding intermediate colors.
 8. 23. 2. Activate the filter
You can find this filter in the image window menu under
Colors → Map → Gradient Map .  8. 22. Color Exchange 8. 24. Palette Map
 Report an error in Bugzilla  13. 11. Grid 13.11. Grid 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 11. Grid 13. 11. 1. Overview Figure 17. 309. Applying example for the Grid filter Original image Filter “ Grid ” applied
It renders a Cartesian grid in the active layer, on top of the existing
contents. The width, spacing, offsets, and colors of the grid lines can
all be set by the user. By default, the lines are with the
GIMP 's foreground color. ( Note: this plug-in
was used to create demonstration images for many of the other plug-ins.)
Tip
If you set the grid line widths to 0, then only the intersections
will be drawn, as plus-marks.
 13. 11. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Pattern → Grid .  13. 11.3. Options Figure 17. 310. “ Grid ” filter options
There are separate options for controlling the horizontal grid
lines, vertical grid lines, and intersections. By default, the
horizontal and vertical settings are locked together, so that
all changes are applied symmetrically. If you want to change
just one of them, click on the “ chain ” symbol below it to
unlock them. The results of changing the Intersection parameters are
rather complex.
Besides, for some options, you can select the unit of measurement
thanks to a drop-down list.
Width
Sets the widths of the horizontal or vertical grid
lines, or of the symbols drawn at their intersections.
Spacing
Sets the distance between grid lines.
The Intersection parameter clears the space
between the intersection point and the end of the arms of the
intersection crosses.
Offset
Sets the offset for grid lines with respect to the upper left
corner . For intersections, sets the length of the arms of the
intersection crosses.
Color Selectors
These allow you to set the colors of the grid lines and
intersection marks.
Figure 17.311. Intersection parameters Width & lt;
2 × Spacing
Width & gt;
2 × Spacing
13.10. Diffraction Patterns 13. 12. Jigsaw
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6. 10. Guillotine 6.10. Guillotine 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 10. Guillotine
The Guillotine command slices up the current
image, based on the image's guides. It cuts the image along each guide,
similar to slicing documents in an office with a guillotine (paper
cutter) and creates new images out of the pieces. For further
information on guides, see
Section 2.2, “Guides” .
 6. 10. 1. Activate the Command
You can access this command from the image menubar through
Image → Transform → Guillotine .  6. 9. Rotation 6. 11. Canvas Size
 Report an error in Bugzilla  8. 36. Hot 8.36. Hot 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 36. 2. Activate the command
You can access the command from the image menu bar through
Colors → Hot .  This command only works on images in RGB mode , and only if the active
layer does not have an alpha channel . Otherwise the menu entry is
insensitive and grayed out.
8.36.3. Options Figure 16.195. “ Hot ” options Mode
You have to select the TV mode: PAL or NTSC.
Action
You can select:
Reduce Luminency Reduce Saturation Blacken : this will turn hot pixels to
black.
Create a new layer
With this option, work will be performed on a new layer instead
of the image. This will give you peace of mind!
8.35. Filter Pack 8.37. Max RGB
 Report an error in Bugzilla  6. 2. HSV Noise 6. 2. HSV Noise 6. Noise Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 2. HSV Noise 6. 2. 1. Overview Figure 17. 126. Example of applying the “ HSV Noise ” filter Original image Filter “ HSV Noise ” applied
The HSV Noise filter creates noise in the active layer or selection by
using the Hue, Saturation, Value (luminosity) color model.
 6. 2. 2. Activate the filter
You can find this filter through
Filters → Noise → HSV Noise .  6. 2.3. Options Figure 17. 127. “ HSV Noise ” filter options Preview
This preview displays interactively changes before they are
applied to the image.
Holdness
This slider (1 -8) controls how much the new pixel color value is
allowed to be applied compared to the existing color. A low
holdness will give an important hue variation. A high holdness
will give a weak variation.
Hue
This slider changes the color of the pixels in a random pattern.
It selects an increasing available color range in the HSV color
circle starting from the original pixel color.
Saturation
This slider increases saturation of scattered pixels.
Value
This slider increases brightness of scattered pixels.
6. Noise Filters 6.3. Hurl
 Report an error in Bugzilla  13. 7. IFS Fractal 13. 7. IFS Fractal 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 7. IFS Fractal 13. 7. 1. Overview Figure 17. 291. Applying example for the IFS Fractal filter Filter “ IFS Fractal ” applied
This fractal-based plug-in is truly wonderful! With this versatile
instrument, you can create amazingly naturalistic organic shapes, like
leaves, flowers, branches, or even whole trees. ( “ IFS ”
stands for “ Iterated Function System ” .)
The key to use this plug-in lies in making very small and precise
movements in fractal space. The outcome is always hard to predict, and
you have to be extremely gentle when you change the pattern. If you make
a component triangle too big, or if you move it too far (even ever so
slightly), the preview screen will black out, or more commonly, you'll
get stuck with a big shapeless particle cloud.
A word of advice: When you have found a pattern you want to work with ,
make only small changes, and stick to variations of that pattern. It's
all too easy to lose a good thing. Contrary to what you might believe,
it's really much easier to create a leaf or a tree with IFS Fractal than
to make a defined geometrical pattern (where you actually know what
you're doing, and end up with the pattern you had in mind).
For a brief introduction to IFS's see Foley and van Dam, et
al ,. Computer Graphics, Principles and
Practice [ FOLEY01 ] .
 13. 7. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Nature → IFS Fractal .  13. 7.3. Options Figure 17. 292. “ IFS Fractal ” filter options
The plug-in interface consists of the compose area to the left, a
preview screen to the right, and some tabs and option buttons at the
bottom of the dialog . The Default setting (in the preview window) is
three equilateral triangles. (This gives rise to a fractal pattern
called the Sierpinski Triangle ).
Toolbar
Click on the toolbar buttons to use the following tools, or open the
context menu of the compose area.
Move, Rotate/Scale, Stretch Select the action to perform using the (mouse) pointer. New, Delete Add or remove fractals. Undo, Redo Standard. Select all Link fractals and let apply actions to all fractals. Recenter
Recompute the center of the fractals. This does not have any
visible effect to the resulting fractal.
Render Options Max. memory
Enables you to speed up rendering time. This is
especially useful when working with a large spot
radius; just remember to use even multiples of the
default value: 4096, 8192, 16384, ...
Iterations
Determines how many times the fractal will repeat
itself. (A high value for Subdivide and Iterations is
for obvious reasons a waste of process time unless
your image is very large .)
Subdivide Controls the level of detail. Spot radius
Determines the density of the “ brushstrokes ” in
the rendered image. A low spot radius is good for thin
particle clouds or spray, while a high spot radius produces
thick, solid color strokes much like watercolor painting. Be
careful not to use too much spot radius — it takes a
lot of time to render.
Spatial Transformation
Gives you information on the active fractal, and allows you to type a
value instead of changing it manually. Changing parameters with the
mouse isn't very accurate, so this is a useful option when you need to
be exact.
X, Y, Scale, Angle, Shear Move, scale, or shear the active fractal. Asymmetry Stretch the active fractal. Flip Flip the active fractal. Color Transformation Simple
Changes the color of the currently selected fractal
component (default is the foreground color in the toolbox)
to a color of your choice.
Full
Like the Simple color transformation but this time you can
manage the color transformation for each color channel and
for the alpha channel (shown as a black channel).
Scale hue by, Scale value by
When you have many fractals with different colors, the
colors blend into each other. So even if you set
“ pure red ” for a fractal, it might actually
be quite blue in some places, while another “ red
” fractal might have a lot of yellow in it. Scale
Hue/Value changes the color strength of the active
fractal, or how influential that fractal color should be.
Other Relative probability
Determines influence or total impact of a certain fractal.
13.7.4. A Brief Tutorial
This is a rather complex plug-in, so to help you understand it, we'll
guide you through an example where you'll create a leaf or branch.
Many forms of life, and especially plants, are built like
mathematical fractals, i.e., a shape that reproduces or repeats
itself indefinitely into the smallest detail. You can easily
reproduce the shape of a leaf or a branch by using four (or
more) fractals. Three fractals make up the tip and sides of the
leaf , and the fourth represents the stem.
Before invoking the filter: Select
File → New Image .
Add a transparent layer with
Layers → Layers and Channels → New Layer .
Set the foreground color in the toolbox to black, and
set the background to white.
Open IFS Fractal. Start by rotating the right and bottom triangles,
so that they point upward. You'll now be able to see the outline of
what's going to be the tip and sides of the leaf . (If you have
problems, it may help to know that the three vertices of a triangle
are not equivalent.)
Figure 17.293. Tutorial Step 2
Start by rotating triangles 2 and 3, trying to keep them nearly
the same size.
To make the leaf symmetrical, adjust the bottom triangle to
point slightly to the left, and the right triangle to point
slightly to the right.
Press New to add a component to the
composition. This is going to be the stem of the leaf, so we
need to make it long and thin. Press
Stretch , and drag to
stretch the new triangle. Don't be alarmed if this messes up
the image, just use Scale to adjust
the size of the overlong
triangle. You'll probably also have to move and rotate the
new fractal to make it look convincing.
Figure 17.294. Tutorial Step 3
Add a fourth component, then stretch, scale, and move it
as shown.
You still have to make it look more leaf-like. Increase the
size of the top triangle, until you think it's thick and
leafy enough. Adjust all fractals until you're happy with
the shape. Right-click to get the pop-up menu, and choose
Select all . Now all components are
selected, and you can scale
and rotate the entire leaf.
Figure 17.295. Tutorial Step 4
Enlarge component 1, arrange the other components
appropriately, then select all, scale and rotate.
The final step is to adjust color. Click on the
Color Transformation tab, and choose
a different color for each fractal. To do this, check
Simple and press the right color
square. A color circle appears, where you can click or
select to choose a color.
Figure 17.296. Tutorial Step 5
Assign a brownish color to component 4, and various shades
of green to the other components.
Press OK to apply the image, and voilà, you've just made a
perfect fractal leaf! Now that you've got the hang of it,
you'll just have to experiment and make your own
designs. All plant-imitating fractals (be they oak trees,
ferns or straws) are more or less made in this fashion,
which is leaves around a stem (or several stems). You just
have to twist another way, stretch and turn a little or add
a few more fractals to get a totally different plant.
13.6. Flame 13.8. Checkerboard
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12.5. Illusion 12. 5. Illusion 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 5. Illusion 12. 5. 1. Overview Figure 17. 255. Illusion Original image Filter “ Fractal Trace ” applied
With this filter , your image (active layer or selection) looks like
a kaleidoscope. This filter duplicates your image in many copies, more
or less dimmed and split, and puts them around the center of the image.
 12. 5. 2. Activate the filter
This filter is found in the image window menu under
Filters → Map → Illusion .  12. 5.3. Options Figure 17. 256.  “ Illusion ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Divisions
That's the number of copies you want to apply to image. This
value varies from -32 to 64. Negative values invert
kaleidoscope rotation.
Mode 1, Mode 2
You have two arrangement modes for copies in image:
Figure 17.257.
From left to right: original image, mode 1, mode 2, with
Divisions=4
12.4. Fractal Trace 12. 6. Make Seamless
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14.2. ImageMap 14.2. ImageMap 14. Web Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  14. 2. ImageMap
In Web sensitive images are frequently used to get some effects when
defined areas are enabled by the pointer. Obviously the most used effect
is a dynamic link to another web page when one of the sensitive areas is
clicked on. This “ filter ” allows you to design easily
sensitive areas within an image. Web site design softwares have this as a
standard function. In GIMP you can do this in a similar
way.
14.2. 1. Overview
This plug-in lets you design graphically and friendly all areas you
want to delimit over your displayed image. You get the relevant part
of html tags that must be merged into the right place in your page html
code. You can define some actions linked to these areas too.
This is a complex tool which is not completely described here
(it works about like Web page makers offering this function). However
we want to describe here some of the most current handlings. If you
want, you can find a more complete descriptions in Grokking the GIMP
with the
link [ GROKKING02 ] .
 14. 2.2. Activate the filter
From an image window, you can find this filter through
Filters → Web → ImageMap  The window is a small one, but you can magnify it.
The main useful areas are:
completely on the left are vertically displayed icons, one for
pointing, three for calling tools to generate various shape areas,
one to edit zone properties, and finally one to erase a selected
zone; you can call these functions with the Mapping menu ,
just on the right is your working area where you can draw all the
shapes areas you want with the relevant tools ,
on the right is displayed an icon vertical set; its use is obvious
but a help pop-up gives you some information about each function ,
finally, even on the right is a display area, as a property list of
the created areas. A click on one item of the list selects
automatically the corresponding shape in the working area,
14. 2.3. Options Figure 17. 344. Imagemap filter options Imagemap window 14.2.3.1. The Menu Bar
The menu bar is similar to the image window menu bar, only a few menus
or menu entries are different:
File Save; Save As
Contrary to other filters, this plug-in doesn't make an
image but a text file. So you must save your work in a
text format.
Tip
With
View → Source
you can preview this text file content.
Open; Open recent
In the plug-in you can open the saved text file. The
areas defined in your file will be loaded and
overdisplayed; if the displayed image is not the
original one or not with the same size,
GIMP will ask you for adapting the
scale.
Edit Edit area info Figure 17.345. Editing an imagemap area
In the settings dialog you can edit the area information
of a selected area. This dialog will pop up automatically
whenever you create a new area.
View
This menu offers you special functions:
Area list
Here you can hide or show the selection area.
Source
Here you see the raw data as you would save it to or read
it from a file.
Color; Grayscale
You can select the image mode here and work with a
Grayscale display.
Mapping
You will seldom use this menu, since you can more easily access
selection tools by clicking on icons on the left of the working
area.
Arrow
The arrow here represents the Move tool. When activated
tool is selected, you can select and move an area on the
image.
With a polygon, you can use the arrow to move one of
the red points. Right-click on a segment between two
red points to open a pop-up menu that offers, with
several others, the possibility to add a new point. If
you right-click on a red point, you can remove it.
Rectangle; Circle; Polygon
These tools let you create various shape areas: click on
the image, move the pointer, and click again.
Edit Map Info Figure 17.346. Editing the imagemap data
With this simple dialog you can enter some items, which
will be written to the resulting output file; either as
comments ( Author ,
Description )
or as attribute values of the HTML tags
( Image name ,
Title ,
Default URL ).
Tools With the “ Tools ” menu
you can create guides and even regularly spaced rectangular areas.
Grid; Grid settings Figure 17.347. Grid options
Here you can enable and disable the image grid or
configure some grid properties.
Use GIMP guides; Create guides
The guide lines are created at the border of the image but
can be moved around by clicking on the red squares on each
line something similar to the GIMP guide lines. By using
the guides you are able to create active rectangles in the
image.
Create guides Figure 17.348. Guide options The guide options
Instead of creating geometrical shapes to select the
active areas you may use an array of rectangles, each
representing an active area, by clicking on the
“ Create guides ” . In the menu popping
up you set the width and height of the rectangles, the
space between them, the number of rows and
columns, and the upper and left startpoint for the array.
All measures are in pixels. If you are not satisfied with
the result you may adjust each rectangle by moving the
red squares as usual.
14.2.3.2. The Tool Bar
Most entries here are just shortcuts for some functions already
described. Exceptions:
Move to Front; Send to Back
Here you can move an area entry to the bottom ( “ Move to
Front ” ) or top ( “ Send to Back ” )
of the area list.
14.2.3.3. The Working Area Figure 17.349. The Working Area
In the main area of the imagemap window, on the left side, you will
find your working area where you can draw all the shapes areas you
want with the relevant tools .
Beside the working area there are vertically displayed icons, one for
pointing, three for calling tools to generate various shape areas, one
to edit zone properties, and finally one to erase a selected zone; you
can call these functions with the Mapping menu too.
Caution
Note that the areas should not overlap.
14.2.3.4. The selection area
On the right is a display area, as a property list of the created
areas. A click on one item of the list selects automatically the
corresponding shape in the working area, then you can modify it.
Beside the display is an icon vertical set; its use is obvious
but a help pop-up gives you some information about each
function .
Unfortunately, the arrow symbols for moving a list entry up or down do
not work here.
But of course you carefully avoided to create overlapping areas, so
you do not use these functions at all.
14. Web Filters 14.3. Semi-Flatten
 Report an error in Bugzilla  4. 7. IWarp 4.7. IWarp 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 7. IWarp 4. 7. 1. Overview Figure 17. 46. Applying example for the IWarp filter Original image Filter “ IWarp ” applied
This filter allows you to deform interactively some parts of the image
and, thanks to its Animate option, to create the elements of a fade
in/fade out animation between the original image and the deformed one,
that you can play and use in a Web page.
To use it, first select a deform type then click on the Preview and drag
the mouse pointer .
 4. 7. 2. Activating the filter
You can find this filter through
Filters → Distort → Iwarp .  4. 7.3. Options
The options of this filter are so numerous that they come in two tabs.
The first tab contains general options. The second tab holds animation
options.
4.7. 3.1. Settings Figure 17. 47. “ IWarp ” filter options ( Settings tab)
The Settings tab allows you to set parameters which will affect
the preview you are working on. So, you can apply different deform
modes to different parts of the preview.
Preview
Here, the Preview is your work space: You click on the
Preview and drag mouse pointer. The underlying part of image
will be deformed according to the settings you have chosen.
If your work is not convenient, press the
Reset button.
Deform Mode Move
Allows you to stretch parts of the
image.
Remove
This remove the distortion where you drag the mouse
pointer, partially or completely. This allows you to avoid
pressing Reset button, working on the whole image. Be
careful when working on an animation: this option will
affect one frame only.
Grow
This option inflates the pointed pattern.
Shrink Self explanatory. Swirl CCW Create a vortex counter clockwise. Swirl CW Create a vortex clockwise. Deform radius
Defines the radius, in pixels (5-100), of the filter action
circle around the pixel pointed by the mouse.
Deform amount
Sets how much out of shape your image will be put (0.0-1.0).
Bilinear
This option smooths the IWarp effect.
Adaptive supersample
This option renders a better image at the cost of increased
calculation.
Max Depth
This value limits the maximum sampling iterations
performed on each pixel.
Threshold
When the value difference between a pixel and the adjacent
ones exceeds this threshold a new sampling iteration is
performed on the pixel.
4.7.3.2. Animate Figure 17.48. “ IWarp ” filter options ( Animation tab)
This tab allows to generate several intermediate images between
the original image and the final deformation of this image. You
can play this animation thanks to the
Playback plug-in.
Number of frames
That's the number of images in your animation (2-100). These
frames are stored as layers attached to your image. Use the
XCF format when saving it.
Reverse
This option plays the animation backwards.
Ping pong
When the animation ends one way, it goes backwards.
4.6. Erase Every Other Row 4.8. Lens Distortion
 Report an error in Bugzilla 
13. 12. Jigsaw 13.12. Jigsaw 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 12. Jigsaw 13. 12. 1. Overview Figure 17. 312. Jigsaw filter example Original image Filter “ Jigsaw ” applied
This filter will turn your image into a jigsaw puzzle.
The edges are not anti-aliased, so a little bit of smoothing often
makes them look better (i. e., Gaussian blur with radius 1.0).
Tip
If you want to be able to easily select individual puzzle-piece
areas, render the jigsaw pattern on a
separate layer filled with solid white, and set the layer mode
to Multiply . You can then select puzzle pieces using the
magic wand (fuzzy
select) tool on the new jigsaw layer.
 13. 12. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Pattern → Jigsaw .  13. 12.3. Options Figure 17. 313. “ Jigsaw ” filter options Number of Tiles
How many tiles across the image is, horizontally and
vertically.
Bevel Edges Bevel width
The Bevel width slider controls the slope of the edges of
the puzzle pieces (a hard wooden puzzle would require a low
Bevel width value, and a soft cardboard puzzle would require
a higher value).
Highlight
The Highlight slider controls the strength of the
highlight that will appear on the edges of each piece. You
may compare it to the "glossiness" of the material the
puzzle is made of. Highlight width is relative to the
Bevel width. As a rule of thumb, the more pieces you add
to the puzzle, the lower Bevel and Highlight values you
should use, and vice versa. The default values are
suitable for a 500x500 pixel image.
Jigsaw Style You can choose between two types of puzzle: Square Then you get pieces made with straight lines. Curved Then you get pieces made with curves. 13.11. Grid 13.13. Maze
 Report an error in Bugzilla 
7. 4. Laplace 7.4. Laplace 7. Edge-Detect Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 4. Laplace 7. 4. 1. Overview Figure 17. 145. Applying example for the Laplace filter Original image Filter “ Laplace ” applied
This filter detects edges in the image using Laplacian method,
which produces thin, pixel wide borders.
 7.4. 2. Activating the filter
You can find this filter through
Filtres → Edge-Detect → Laplace .  7. 3. Edge 7. 5. Neon
 Report an error in Bugzilla  4.8. Lens Distortion 4. 8. Lens Distortion 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 8. Lens Distortion 4. 8. 1. Overview Figure 17. 49. Example for the “ Lens Distortion ” filter Original image “ Lens Distortion ” applied
This filter lets you simulate but also correct the typical distortion
effect introduced in photo images by the glasses contained in the camera
lenses.
 4. 8. 2. Activating the filter
This filter is found in the image window menu under
Filters → Distorts → Lens Distortion .  4. 8.3. Options Figure 17. 50. “ Lens Distortion ” options
The allowed range of all options is from -100.0 to 100.0.
Preview
The result of your settings will appear in the Preview without
affecting the image until you click on OK . Main
The amount of spherical correction to introduce. Positive values
make the image convex while negative ones make it concave. The
whole effect is similar to wrapping the image inside or outside a
sphere.
Figure 17.51. Example result of Main option -100.0 0.0 +100.0 Edge
Specifies the amount of additional spherical correction at image
edges.
Figure 17.52. Example result of Edge option (Main set to 50.0) -60.0 0.0 +60.0 Zoom
Specifies the amount of the image enlargement or reduction caused
by the hypothetical lens.
Figure 17.53. Example result of Zoom option -100.0 0.0 +100.0 Brighten
The amount of the “ vignetting ” effect: the brightness
decrease/increase due to the lens curvature that produces a
different light absorption.
The Main or Edge options
must be non zero for this option to produce noticeable results.
Figure 17.54. Example result of Brigthen option (Main set to 75.0) -25.0 0.0 +25.0 X shift, Y shift
These two options specify the shift of the image produced by not
perfectly centered pairs of lenses.
As above this option produces visible results only if the
Main or Edge options
are non zero.
Figure 17.55. Example result of X shift option (Main set to 70.0) -100.0 0.0 +100.0 4.7. IWarp 4.9. Mosaic
 Report an error in Bugzilla  10. 11. Van Gogh (LIC) 10.11. Van Gogh (LIC) 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 11. Van Gogh (LIC) 10. 11. 1. Overview Figure 17. 202.
From left to right: original image, map, resulting image
Map has three stripes: a solid black area, a vertical gradient
area, a solid white area. One can see, on the resulting image,
that image zones corresponding to solid areas of the map, are not
blurred. Only the image zone corresponding to the gradient area of
the map is blurred.
“ LIC ” stands for Line Integral Convolution, a
mathematical method.
The plug-in author uses mathematical terms to name his options...
This filter is used to apply a directional blur to an image, or to
create textures. It could be called “ Astigmatism ” as it
blurs certain directions in the image.
It uses a blur map. Unlike other maps, this filter doesn't use grey
levels of this blur map. Filter takes in account only
gradient direction(s) . Image pixels corresponding to
solid areas of the map are ignored.
 10. 11. 2. Activate the filter
You can find this filter through
Filters → Artistic → Van Gogh (LIC) .  10. 11.3. Options Figure 17. 203. “ Van Gogh (LIC) ” filter options Tip
To create a blur, check With Source Image .
Only Filter Length slider and perhaps Integration Steps slider,
are useful.
To create a texture, check With White Noise .
All sliders can be useful.
Effect Channel
By selecting Hue , Saturation
or Brightness (=Value) , filter
will use this channel to treat image.
Effect Operator
The “ Derivative ” option reverses “ Gradient
” direction:
Figure 17.204. Derivative option example
Using a square gradient map, Effect operator is on
“ Gradient ” on the left, on
“ Derivative ” on the right: what was sharp is
blurred and conversely.
Convolve
You can use two types of convolution. That's the first parameter
you have to set:
With white noise
White noise is an acoustics name. It's a noise where all
frequencies have the same amplitude. Here, this option is
used to create patterns.
With source image The source image will be blurred. Effect image
That's the map for blur or pattern direction. This map must have
the same dimensions as the original image. It must be preferably a
grayscale image. It must be present on your screen when you call
filter so that you can choose it in the drop-list.
Figure 17.205. Blurring with vertical gradient map
With a vertical gradient map, vertical lines are blurred.
Figure 17.206. Blurring with a square gradient map
The gradient map is divided into four gradient triangles:
each of them has its own gradient direction. In every area
of the image corresponding to gradient triangles, only lines
with the same direction as gradient are blurred.
Figure 17.207. Texture example
The “ With white noise ”
option is checked. Others are default. With a vertical
gradient map, texture “ fibres ”
are going horizontally.
Filter length
When applying blur, this option controls how important blur is.
When creating a texture, it controls how rough texture is: low
values result in smooth surface; high values in rough surface.
Figure 17.208. Action example of Filter Length on blur
On the left: a vertical line, one pixel wide (zoom 800%). On
the right: the same line, after applying a vertical blur
with a Filter Length to 3. You can see that blur width is 6
pixels, 3 pixels on both sides.
Figure 17.209. Filter Length example on texture
On the left: a texture with Filter Length=3. On the right,
the same texture with Filter Length=24.
Noise magnitude
This options controls the amount and size of White Noise. Low
values produce finely grained surfaces. High values produce
coarse-grained textures.
Figure 17.210. Action example of Noise Magnitude on texture Noise magnitude = 4 Integration steps
This options controls the influence of gradient map on texture.
Figure 17.211. Action example of Integration Steps on texture
On the left: Integration Steps = 2. On the right:
Integration Steps = 4.
Minimum value, Maximum value
Both values determine a range controlling texture contrast:
shrunk range results in high contrast and enlarged range results
in low contrast.
Figure 17.212. Action example of min/max values on texture
Minimum value = -4.0. Maximum value = 5.0.
10.10. Softglow 10.12. Weave
 Report an error in Bugzilla  5. 4. Lighting Effects 5. 4. Lighting Effects 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 4. Lighting Effects 5. 4. 1. Overview Figure 17. 99. The same image, before and after applying Lighting filter Original image Filter “ Lighting Effects ” applied
This filter simulates the effect you get when you light up a wall with
a spot. It doesn't produce any drop shadows and, of course, doesn't
reveal any new details in dark zones.
 5. 4. 2. Activate the filter
This filter is found in the image window menu under
Filters → Light and Shadow → Lighting Effects .  5. 4.3. Options Figure 17. 100.  “ Lighting ” filter options Preview
When Interactive is checked, parameter
setting results are interactively displayed in preview without
modifying the image until you click on OK
button. 
If Interactive is not checked, changes are
displayed in preview only when you click on the
Update button.
This option is useful with a slow computer.
Any other options are organized in tabs:
5.4.3.1. General Options Figure 17.101.
“ Lighting ” filter options ( General Options)
Transparent background
Makes destination image transparent when bumpmap height
is zero (height is zero in black areas of the bumpmapped
image).
Create new image
Creates a new image when applying filter.
High quality preview
For quick CPU...
Distance
You can specify the distance of the light source from the
center of the image with this slider. The range of values
is from 0.0 to 2.0.
5.4.3.2. Light Settings Figure 17.102.
“ Lighting ” filter options ( Light Settings)
In this tab, you can set light parameters. With
Light 1 ...
Light 6 you can create six light sources
and work on each of them separately.
Type
The filter provides several light types in
a drop-down list :
Point
Displays a blue point at center of preview. You can click
and drag it to move light all over the preview.
Directional
The blue point is linked to preview center by a line which
indicates the direction of light.
None
This deletes the light source (light may persist...).
Color
 When you click on the color swatch , you bring a dialog up
where you can select the light source color.  Intensity
With this option, you can set light intensity.
Position
Determines the light point
position according to three coordinates: X coordinate for
horizontal position, Y for vertical position, Z for source
distance (the light darkens when distance increases). Values
are from -1 to +1.
Direction
This option should allow you to fix the light direction in
its three X , Y
and Z coordinates.
Isolate
With this option, you can decide whether all light sources
must appear in the Preview, or only the source you are
working on.
Lighting preset
You can save your settings with the Save
and get them back later with the
Open .
5.4.3.3. Material Properties Figure 17.103.
“ Lighting ” filter options ( Material Properties)
These options don't concern light itself, but light reflected by
objects.
Small spheres, on both ends of the input boxes, represent the
action of every option, from its minimum (on the left) to its
maximum (on the right). Help pop ups are more useful.
Glowing
With these option, you can set the amount of original
color to show where no direct light falls.
Bright
With this option, you can set the intensity of original
color when hit directly by a light source.
Shiny
This option controls how intense the highlight will be.
Polished
With this option, higher values make the highlight more
focused.
Metallic
When this option is checked , surfaces look metallic.
5.4.3.4. Bump Map Figure 17.104.
“ Lighting ” filter options ( Bump Map)
In this tab, you can set filter options that give relief to the
image. See Bump mapping .
Enable bump mapping
With this option, bright parts of the image will appear
raised and dark parts will appear depressed. The aspect
depends on the light source position.
Bumpmap image
You have to select there the grey-scale image that will
act as a bump map. See Bump
Map plug-in for additional explanations.
Curve
This option defines the method that will be used when applying
the bump map; that is, the bump height is a function of the
specified curve.
Four curve types are available:
Linear ,
Logarithmic ,
Sinusoidal and
Spherical .
Maximum height
This is the maximum height of bumps.
5.4.3.5. Environment Map Figure 17.105.
“ Lighting ” filter options ( Environment Map)
Enable environment mapping
When you check this box, the following option is enabled:
Environment image
You have to select there a RGB image, present on your
screen. Please note that for this option to work you
should load another image with GIMP
before using it.
An example can be found at
[ BUDIG01 ] .
5.3. Lens Flare 5.5. Sparkle
 Report an error in Bugzilla 
12.6. Make Seamless 12.6. Make Seamless 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 6. Make Seamless 12. 6. 1. Overview Figure 17. 258. An example of Make Seamless. Original Make Seamless applied
This filter modifies the image for tiling by creating seamless edges.
Such an image can be used as a pattern for a web-page . This filter has
no option, and result may need correction.
 12.6.2. Activation
You can find this filter through
Filters → Map → Make Seamless  12. 5. Illusion 12. 7. Map Object
 Report an error in Bugzilla  12.7. Map Object 12. 7. Map Object 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 7. Map Object 12. 7. 1. Overview Figure 17. 259.
The “ Map Object ” filter applied to a photograph
Original “ Map Object ” applied
This filter maps a picture to an object (plane, sphere, box or
cylinder).
 12. 7. 2. Activate the filter
This filter is found in the image window menu under
Filters → Map → Map Object .  12. 7.3. Options 12.7.3.1. Preview This preview has several possibilities: Preview!
Preview is automatic for some options but you will have to press
this button to update Preview after modifying many other
parameters.
When mouse pointer is on Preview and the Light tab is selected,
it takes the form of a small hand to grab the blue
point which marks light source origin and to
displace it.
This blue point may not be visible if light source has negative
X and Y settings in the Light tab.
Zoom out, Zoom in
Zoom buttons allow you to enlarge or to reduce image in Preview.
Their action is limited, but may be useful in case of a large
image.
Show preview wireframe
Puts a grid over the preview to make displacements and rotations
more easy. Works well on a plan.
12.7.3.2. General Options Figure 17.260. “ Map Object ” options ( General) Map to
This drop-down list allows you to select the object the image
will be mapped on. It can be a Plane , a
Sphere , a Box or a
Cylinder .
Transparent background
This option makes image transparent around the object. If not
set, the background is filled with the current background color .
Tile source image
When moving Plane object and displacing it with Orientation tab
options, a part of the image turns empty. By checking the
Tile source image , source image copies
will fill this empty space in. This option seems not to work
with the other objects.
Note
This option works with “ Plane ” only.
Create new image
When this option is checked , a new image is created with the
result of filter application, so preserving the original image.
Enable antialiasing
Check this option to conceal this unpleasant aliasing effect
on borders. When checked, this option lets appear two settings:
Depth
Defines antialiasing quality, to the detriment of
execution speed.
Threshold
Defines antialiasing limits. Antialiasing stops when value
difference between pixels becomes lower than this set
value.
12.7.3.3. Light Figure 17.261. “ Map Object ” options ( Light) Light Settings Lightsource type
In this dropdown list, you can select among
Point light , Directionnal
light and No light .
Lightsource color
Press this button to open the Color Selector dialog.
Position
If “ Point light ” is selected, you can control there
light source Position (the blue point),
according to X, Y and Z coordinates.
If “ Directional light ” is selected, these X, Y and
Z parameters control the “ Direction vector ”
(effect is not evident).
12.7.3.4. Material Figure 17.262. “ Map Object ” options ( Material) Intensity Levels Ambient
Amount of color to show where no light falls directly.
Diffuse
Intensity of original color when lit by a light source.
Reflectivity Diffuse
Higher values make object reflect more light (looks
brighter).
Specular
Controls how intense the highlights will be.
Highlight
Higher values make the highlights more focused.
12.7.3.5. Orientation Figure 17.263. “ Map Object ” options ( Orientation) Position
These three sliders and their input boxes allows you to vary
object position in image, according to the X, Y, Z coordinates
of the object upper left corner.
Rotation
These three sliders make the object rotate around X, Y, Z axes
respectively.
12.7.3.6. Box
This tab appears only when you select the Box object.
Figure 17.264. “ Map Object ” options ( Box) Match Images to Box Faces
This function name is self explanatory: you can select an image
for every face of the box. These images must be present on your
screen when you call the Map Object filter.
Scale
These X, Y, Z sliders allow you to change the size of
every X, Y, Z dimension of the box.
12.7.3.7. Cylinder
This tab appears only when you select the Cylinder object.
Figure 17.265. “ Map Object ” options ( Cylinder) Images for the Cap Faces
The name of this option is self-explanatory. Images must be
present on your screen when you call the Map Object filter.
Size Radius
This slider and its input boxes let you control the
Cylinder diameter. Unfortunately, this setting works on the
image mapped onto the cylinder and resamples this image to
adapt it to the new cylinder size. It would be better to
have the possibility of setting size cylinder before mapping
so that we could map a whole image.
Length
Controls cylinder length.
12.6. Make Seamless 12.8. Paper Tile
 Report an error in Bugzilla  8. 37. Max RGB 8.37. Max RGB 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 37. 2. Activate the filter
This filter is found in the image window menu under
Colors → Max RGB .  8. 37.3. Options Figure 16.197. “ Max RGB ” options Preview
This preview displays, in real time, the resulting image after
treatment by filter.
Parameter Settings Hold the maximal channels : For every pixel,
the filter keeps intensity of the RGB color channel which has
the maximal intensity and reduces other both to zero. For
example: 220, 158, 175 max-- & gt; 220, 0, 0. If two channels have
same intensity, both are held: 210, 54, 210 max-- & gt; 210, 0, 210.
Hold the minimal channels : For every pixel,
the filter keeps intensity of the RGB color channel which has
the minimal intensity and reduce both others to zero. For
example: 220, 158, 175 min-- & gt; 0, 158, 0. If two minimal
channels have same intensity, both are held: 210, 54, 54
min-- & gt; 0, 54, 54.
Grey levels are not changed since light intensity is the same in
all three channels.
8.36. Hot 8.38. Retinex
 Report an error in Bugzilla 
13. 13. Maze 13.13. Maze 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 13. Maze 13. 13. 1. Overview Figure 17. 314. An example of a rendered maze. Filter “ Maze ” applied
This filter generates a random black and white maze
pattern. The result completely overwrites the previous
contents of the active layer . A typical example is shown
below. Can you find the route from the center to the edge?
 13. 13. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Pattern → Maze .  13. 13.3. Options Figure 17. 315. “ Maze ” filter options Maze Size Width, Height
These sliders control how many pathways the maze should have. The
lower the values for width and height, the more paths you will
get. The same happens if you increase the number of pieces in the
Width and Height Pieces fields. The result
won't really look like a maze unless the width and height are
equal.
Algorithm Seed
You can specify a seed for the random number generator, or
ask the program to generate one for you. Unless you need
to later reproduce exactly the same maze, you might as
well have the program do it.
Depth first, Prim's algorithm
You can choose between these two algorithms for maze. Only a
computer scientist can tell the difference between them.
Tileable
If you want to use it in a pattern, you can make the maze
tileable by checking this check-button.
13.12. Jigsaw 13.14. Qbist
 Report an error in Bugzilla  2.5. Motion Blur 2. 5. Motion Blur 2. Blur Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 5. Motion Blur 2. 5. 1. Overview Figure 17. 13. Starting example for Motion Blur filter Original image Linear blur Figure 17.14. Using example for Motion Blur filter Radial blur Zoom blur
The Motion Blur filter creates a movement blur. The filter is capable of
Linear, Radial, and Zoom movements. Each of these movements can be
further adjusted, with Length, or Angle settings available.
 2. 5. 2. Activate the filter
You can find this filter in the image menu under
Filters → Blur → Motion Blur  2. 5.3. Options Figure 17. 15. “ Motion Blur ” filter options Blur Type Linear
Is a blur that travels in a single direction,
horizontally, for example. In this case, Length means as
Radius in other filters:it represents the blur intensity.
More Length will result in more blurring . Angle describes
the actual angle of the movement. Thus, a setting of 90
will produce a vertical blur, and a setting of 0 will
produce a horizontal blur.
Radial
motion blur that creates a circular blur. The Length
slider is not important with this type of blur. Angle on
the other hand, is the primary setting that will affect
the blur. More Angle will result in more blurring in a
circular direction. The Radial motion blur is similar to
the effect of a spinning object. The center of the spin
in this case, is the center of the image.
Zoom
Produces a blur that radiates out from the center of the
image. The center of the image remains relatively calm,
whilst the outer areas become blurred toward the
center. This filter option produces a perceived forward
movement, into the image. Length is the main setting
here, and affects the amount of speed, as it were, toward
the center of the image.
Blur Parameters Length
This slider controls the distance pixels are moved (1 -
256)
Angle
As seen above, Angle slider effect depends on Blur type
(0 - 360).
Blur Center
With this option, you can set the starting point of movement.
Effect is different according to the Blur Type you have selected.
With Radial Type for instance, you set rotation center. With Zoom
Type, vanishing point. This option is greyed out with Linear type.
Tip
You have to set the blur center coordinates. Unfortunately, you
can't do that by clicking on the image . But, by moving mouse
pointer on the image , you can see its coordinates in the lower
left corner of the image window . Only copy them out into the
input boxes.
2.4. Selective Gaussian Blur 2. 6. Pixelise
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4. 9. Mosaic 4.9. Mosaic 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 9. Mosaic 4. 9. 1. Overview Figure 17. 56. Applying example for the “ Mosaic ” filter Original image Filter “ Mosaic ” applied
It cuts the active layer or selection into many squares or polygons
which are slightly raised and separated by joins, giving so an aspect
of mosaic.
 4. 9. 2. Activating the filter
You can find this filter through
Filters → Distorts → Mosaic .  4. 9.3. Options Figure 17. 57. “ Mosaic ” filter options Preview
All your setting changes will appear in the Preview without
affecting the image until you click on OK . Note that the preview displays only a part of the whole image if
the filter is applied to an selection. Don't keep
Preview checked if your computer is too slow.
Tiling primitives
This option is self-understanding:
Squares 4 edges Hexagons 6 edges (hexa = 6) Octagons & squares 8 or 4 edges (octa = 8) Triangles 3 edges (tri = 3) Tile size
Slider and input box allow you to set the size of tile
surface.
Tile height
That's ledge, relief of tiles. Value is width of the lit
border in pixels.
Tile spacing
That's width of the join between tiles.
Tile neatness
When set to 1, most of tiles have the same size. With 0
value, size is determined at random and this may lead to
shape variation.
Light direction
By default light comes from the upper left corner
(135°). You can change this direction from 0 to 360
(counter clockwise).
Color variation
Each tile has only one color. So the number of colors is reduced,
compared to the original image. Here you can increase the number
of colors a little.
Antialiasing
This option reduces the stepped aspect that may have
borders.
Color averaging
When this option is unchecked, the image drawing can be
recognized inside tiles. When checked, the colors inside
tiles are averaged into a single color.
Allow tile splitting
This option splits tiles in areas with many colors, and
so allows a better color gradation and more details in
these areas.
Pitted surfaces
With this option tile surface looks pitted.
FG/BG lighting
When this option is checked , tiles are lit by the
foreground color of the toolbox, and shadow is colored by
the background color. Joins have the background color.
4.8. Lens Distortion 4. 10. Newsprint
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7. 5. Neon 7.5. Neon 7. Edge-Detect Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 5. Neon 7. 5. 1. Overview Figure 17. 146. Applying example for the Neon filter Original image Filter “ Neon ” applied
This filter detects edges in the active layer or selection and gives
them a bright neon effect.
You will find in GIMP a Script-Fu also named Neon,
which works in a different manner. The Script-Fu is an easy shortcut to
construct logo-like letters outlined with a configurable neon-effect.
See Section 16.17, “Neon” for details.
 7.5. 2. Activating the filter
You can find this filter through
Filters → Edge-Detect → Neon... .  7. 5.3. Options Figure 17. 147. Neon filter options Radius
This option lets you determine how wide the detected edge will be.
Amount
This option lets you determine how strong the filter effect will
be .
7.4. Laplace 7.6. Sobel
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4. 10. Newsprint 4.10. Newsprint 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 10. Newsprint 4. 10. 1. Overview Figure 17. 58. Applying example for the Newsprint filter Original image Filter “ Newsprint ” applied
This filter halftones the image using a clustered-dot dither. Halftoning
is the process of rendering an image with multiple levels of grey or
color (i.e. a continuous tone image) on a device with fewer tones;
often a bi-level device such as a printer or typesetter.
The basic premise is to trade off resolution for greater apparent tone
depth (this is known as spatial dithering).
There are many approaches to this, the simplest of which is to throw
away the low-order bits of tone information; this is what the posterize
filter does. Unfortunately, the results don't look too good. However, no
spatial resolution is lost.
This filter uses a clustered-dot ordered dither, which reduces the
resolution of the image by converting cells into spots which grow or
shrink according to the intensity that cell needs to represent.
Imagine a grid super-imposed on the original image. The image is
divided into cells by the grid - each cell will ultimately hold a single
spot made up of multiple output pixels in order to approximate the
darkness of the original image in that cell.
Obviously, a large cell size results in a heavy loss in resolution! The
spots in the cells typically start off as circles, and grow to be
diamond shaped. This change in shape is controlled by a
Spot function . By using different spot
functions, the evolution in the shape of the spots as the cell goes from
fully black to fully white may be controlled.
 4. 10. 2. Starting filter
You can find this filter through
Filters → Distorts → Newsprint .  4. 10.3. Options Figure 17. 59. “ Newsprint ” filter options Preview
All your setting changes will appear in the Preview without
affecting the image until you click on OK . Note that the preview displays only a part of the whole image if
the filter is applied to an selection. Don't keep
Preview checked if your computer is too slow.
Resolution
This group controls the cell size, either by setting the input and
output resolutions, or directly.
Input SPI
Resolution of the original input image, in Samples Per Inch
(SPI). This is automatically initialised to the input
image's resolution.
Output LPI
Desired output resolution, in Lines Per Inch (LPI).
Cell size
Resulting cell size, in pixels. Most often you will want to
set this directly.
Screen Separate To RGB, CMYK, Intensity
Select which colorspace you wish to operate in. In
RGB mode, no colorspace conversion is
performed. In CMYK , the image is first
internally converted to CMYK, then each color channel is
separately halftoned, before finally being recombined back
to an RGB image. In Intensity mode,
the image is internally converted to grayscale, halftoned,
then the result used as the alpha channel for the input
image. This is good for special effects, but requires a
little experimentation to achieve best results. Hint: try
CMYK if you don't know which to go for initially.
Black pullout (%)
When doing RGB- & gt;CMYK conversion, how much K (black)
should be used?
Lock channels
Make channel modifications apply to all channels.
Factory Defaults
Restore the default settings which should give pleasing
results.
Angle Cell grid angle for this channel. Spot function
Spot function to be used for this channel (see preview in
blue cell-boxes).
Antialiasing
Proper halftoning does not need antialiasing: the aim is to
reduce the color depth after all! However, since this
plugin is mainly for special effects, the results are
displayed on screen rather than by a black/white printer.
So it is often useful to apply a little anti-aliasing to
simulate ink smearing on paper. If you do want to print the
resulting image then set the antialising to 1 (ie, off).
Oversample
Number of subpixels to sample to produce each output pixel.
Set to 1 to disable this feature. Warning: large numbers
here will lead to very long filter runtimes!
4.10.4. Example Figure 17.60. Example for Newsprint An example from plug-in author 4.9. Mosaic 4.11. Page Curl
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3. 6. NL Filter 3.6. NL Filter 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 6. NL Filter 3. 6. 1. Overview Figure 17. 25. Example for the NL-Filter Original image “ NL Filter ” applied
NL means “ Non Linear ” . Derived from the Unix
pnmnlfilt program, it joins smoothing, despeckle
and sharpen enhancement functions. It works on the whole layer , not
on the selection.
This is something of a swiss army knife filter. It has 3 distinct
operating modes. In all of the modes each pixel in the image is examined
and processed according to it and its surrounding pixels values. Rather
than using 9 pixels in a 3x3 block, it uses an hexagonal block whose
size can be set with the Radius option.
 3. 6. 2. Activating the filter
You can find this filter through
Filters → Enhance → NL Filter .  The filter does not work if the active layer has an alpha channel . Then
the menu entry is insensitive and grayed out. 3. 6.3. Options Figure 17. 26. “ NL Filter ” options Preview
When checked, parameter setting results are interactively
displayed in preview.
Filter
The Operating Mode
is described below.
Alpha
Controls the amount of the filter to apply. Valid range is
0.00-1.00. The exact meaning of this value depends on the selected
operating mode. Note that this parameter is related to but not
the same as the alpha parameter used in the
pnmnlfilt program.
Radius
Controls the size of the effective sampling region around each
pixel. The range of this value is 0.33-1.00, where 0.33 means just
the pixel itself (and thus the filter will have no effect), and
1.00 means all pixels in the 3x3 grid are sampled.
3.6.4. Operating Modes
This filter can perform several distinct functions:
Alpha trimmed mean
The value of the center pixel will be replaced by the mean of
the 7 hexagon values, but the 7 values are sorted by size and
the top and bottom Alpha portion of the 7
are excluded from the mean. This implies that an
Alpha value of 0 .0 gives the same sort of
output as a normal convolution (i.e. averaging or smoothing
filter), where Radius will determine the
“ strength ” of the filter. A good value to start from
for subtle filtering is
Alpha = 0. 0,
Radius = 0.55 .
For a more blatant effect, try
Alpha = 0.0 and
Radius = 1.0.
An Alpha value of 1.0 will cause the
median value of the 7 hexagons to be used to replace the center
pixel value. This sort of filter is good for eliminating
“ pop ” or single pixel noise from an image without
spreading the noise out or smudging features on the image.
Judicious use of the Radius parameter will
fine tune the filtering.
Intermediate values of Alpha give effects
somewhere between smoothing and "pop" noise reduction. For subtle
filtering try starting with values of
Alpha = 0. 8,
Radius = 0.6.
For a more blatant effect try
Alpha = 1.0,
Radius = 1.0 .
Optimal estimation
This type of filter applies a smoothing filter adaptively over
the image. For each pixel the variance of the surrounding
hexagon values is calculated, and the amount of smoothing is
made inversely proportional to it. The idea is that if the
variance is small then it is due to noise in the image, while if
the variance is large, it is because of “ wanted ”
image features.
As usual the Radius parameter controls
the effective radius , but it probably advisable to leave the
radius between 0.8 and 1.0 for the variance calculation to be
meaningful. The Alpha parameter sets the
noise threshold, over which less smoothing will be done. This
means that small values of Alpha will
give the most subtle filtering effect, while large values will
tend to smooth all parts of the image. You could start with
values like
Alpha = 0.2,
Radius = 1.0 ,
and try increasing or decreasing the
Alpha parameter to get the desired
effect. This type of filter is best for filtering out dithering
noise in both bitmap and color images.
Edge enhancement
This is the opposite type of filter to the smoothing filter. It
enhances edges. The Alpha parameter
controls the amount of edge enhancement, from subtle (0.1) to
blatant (0.9). The Radius parameter
controls the effective radius as usual, but useful values are
between 0.5 and 0.9. Try starting with values of
Alpha = 0. 3,
Radius = 0.8.
Combination use
The various operating modes can be used one after the other to get the
desired result. For instance to turn a monochrome dithered image into
grayscale image you could try one or two passes of the smoothing
filter, followed by a pass of the optimal estimation filter , then some
subtle edge enhancement. Note that using edge enhancement is only
likely to be useful after one of the non-linear filters (alpha
trimmed mean or optimal estimation filter), as edge enhancement is the
direct opposite of smoothing.
For reducing color quantization noise in images (i.e. turning .gif
files back into 24 bit files) you could try a pass of the optimal
estimation filter ( Alpha = 0.2,
Radius = 1.0 ), a pass of the median filter
( Alpha = 1. 0, Radius =
0.55 ), and possibly a pass of the edge enhancement filter. Several
passes of the optimal estimation filter with declining
Alpha values are more effective than a single
pass with a large Alpha value. As usual, there
is a trade-off between filtering effectiveness and losing detail.
Experimentation is encouraged.
3.5. Destripe 3.7. Red Eye Removal  Report an error in Bugzilla 
8. 10. Normalize 8.10. Normalize 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8.10. Normalize
The Normalize command scales the brightness
values of the active layer so that the darkest point becomes black
and the brightest point becomes as bright as possible, without altering
its hue. This is often a “ magic fix ” for images that are
dim or washed out. “ Normalize ” works on layers from RGB,
Grayscale, and Indexed images.  8. 10. 1. Activate the Command
You can access this command from the image menu bar through
Colors → Auto → Normalize .  8. 10.2. “ Normalize ” Example Figure 16. 138. Original image
The active layer and its Red, Green and Blue
histograms before “ Normalize ” .
Figure 16.139. Image after the command
The active layer and its Red, Green and
Blue histograms after “ Normalize ” . The contrast is
enhanced.
Histogram stretching creates gaps between the pixel columns,
giving it a striped look.
8. 9. Color Enhance 8.11. Stretch Contrast
 Report an error in Bugzilla  5. 6. Supernova 5.6. Supernova 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 6. Supernova 5. 6. 1. Overview Figure 17. 108. Applying example for the Supernova filter Original image Filter “ Supernova ” applied
This filter creates a big star reminding a super-nova. It works with
RGB and GRAY images. Light effect decreases according to 1/r where r
is the distance from star center.
 5.6. 2. Activate the filter
This filter is found in the image window menu under
Filters → Light and Shadow → Supernova .  5. 6. 3. Parameter Settings Figure 17. 109.  “ Supernova ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Center of Nova X , Y
You can use input boxes to set horizontal (X) and vertical
(Y) coordinates of SuperNova center. You can also click the
SuperNova center in the preview box.
Tip
To center Supernova precisely, select
“ percent ” option in the Unit dropdown list
and fix X and Y to 50%.
Show position
This option brings up a reticle in preview, centered on the
SuperNova.
Color
When you click on the color swatch , you bring up the usual color
selector.
Radius
This is radius of the SuperNova center (1-100). When you
increase the value, you increase the number of central white
pixels according to r*r (1, 4, 9...).
Spikes
This is number of rays (1-1024). Each pixel in the nova center
emit one pixel wide rays. All these rays are more or less
superimposed resulting in this glittering effect you get when
you move this slider.
Random hue
Color rays at random. (0-360) value seems to be a range in
HSV color circle.
5.5. Sparkle 5.7. Drop Shadow
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10. 7. Oilify 10.7. Oilify 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 7. Oilify 10. 7. 1. Overview Figure 17. 191. Example for the “ Oilify ” filter Original image Filter “ Oilify ” applied
This filter makes the image look like an oil painting. The
Mask size controls the outcome: a high value gives
the image less detail, as if you had used a larger brush.
Tip
The GIMPressionist filter can produce similar effects, but
allows a much wider variety of options.
 10. 7. 2. Activate the filter
This filter is found in the image menu through
Filters → Artistic → Oilify... .  10. 7.3. Options Figure 17. 192. “ Oilify ” filter options Mask size
Mask size selects the size of the brush mask used to paint the
oily render. Larger values here produce an oilier render.
Use mask-size map
You may use a mask-size map to control
Mask size partially. Mask size is
reduced accordings to darkness in each pixel of the map image.
You can select a map image among the current opened images of the
same size as the source image.
Exponent
Exponent selects density of the brush mask used to paint the
oily render.
Use exponent map
You may use an exponent map to control density of brush touch
partially. Density is reduced accordings to darkness in each pixel
of the map image. You can select a map image among the current
opened images of the same size as the source image.
Use intensity algorithm “ Use intensity algorithm ” changes the mode of
operation to help preserve detail and coloring.
10.6. GIMPressionist 10.8. Photocopy
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15. 7. Optimize 15.7. Optimize 15. Animation Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. 7. Optimize 15.7. 1. Overview
An animation can contain several layers and so its size can be
important. This is annoying for a Web page. The Optimize filters let you
reduce this size. Many elements are shared by all layers in an
animation; so they can be saved only once instead of being saved in all
layers, and what has changed in each layer can be saved only.
GIMP offers two Optimize filters: Optimize
(Difference) and Optimize (GIF) . Their
result doesn't look very different.
15.7.2. Activate filters
You can find these filters in the image menu:
Filters → Animation → Optimize ( Difference)
Filters → Animation → Optimize ( for GIF)
Filters → Animation → Unoptimize
15.7.3. Example for the Optimize animation filters Original image
In this animation, the red ball goes downwards and past vertical bars.
File size is 600 Kb.
Optimize (Difference)
File size moved to 153 Kb. Layers held only the part the background
which will be used to remove the trace of the red ball. The common part
of layers is transparent.
Optimize (GIF)
File size moved to 154 Kb, a bit bigger in the present example, but
layer size has been reduced. Layers held only a rectangular selection
which includes the part of the background which will be used to remove
the trace of the red ball. The common part of layers is transparent.
15.7.4. Unoptimize
The “ Unoptimize ” filter removes any optimizations on a
layer-based animation. You may need this command if you want to edit the
animation and it's not possible or not useful to
undo any changes and start
editing from the original image.
15.6. Waves 15.8. Playback
 Report an error in Bugzilla  4. 11. Page Curl 4. 11. Page Curl 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 11. Page Curl 4.11. 1. Overview Figure 17. 61. Example for the Page Curl filter Original image Filter “ Page Curl ” applied
This filter curls a corner of the current layer or selection into a
kind of cornet showing the underlying layer in the cleared area. A new
“ Curl Layer ” and a new Alpha channel are created. The part
of the initial layer corresponding to this cleared area is also
transparent.
 4. 11. 2. Activating the filter
This filter is found in the image window menu under
Filters → Distorts → Page Curl .  4. 11.3. Options Figure 17. 62. Options Curl Location
You have there four radio buttons to select the corner you want
raise. The Preview is redundant and doesn't respond to other
options.
Curl Orientation Horizontal and Vertical
refer to the border you want raise.
Shade under curl
This is the shadow inside the cornet.
Foreground / background colors, Current gradient, Current gradient (reversed)
This option refers to the outer face of the cornet.
Opacity
Refers to the visibility of the layer part underlying the cornet.
It may be set also in the Layer Dialog.
4.10. Newsprint 4.12. Polar Coords
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8. 24. Palette Map 8.24. Palette Map 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 24. Palette Map 8.24. 1. Overview
This plug-in recolors the image using colors from the active palette
that you choose in
Dialogs → Palettes .
It maps the contents of the specified drawable (layer, selection...)
with the active palette. It calculates luminosity of each pixel and
replaces the pixel by the palette sample at the corresponding index. A
complete black pixel becomes the lowest palette entry, and complete
white becomes the highest. Works on both Grayscale and RGB image
with/without alpha channel.
8.24. 2. Activate the filter
You can access this filter in the image window menu under
Colors → Map → Palette Map .
8.24.3. Example Figure 16.168. The active palette is applied to a gradient image
The current palette, with 18 colors
The colors of the active palette are applied to a black to white
gradient . The color with the lowest index in the palette (orange)
replaces the black color in the gradient. The color with the
highest index in the palette (red) replaces the white color in
the gradient. The other colors spread out in the order of the
palette.
8.23. Gradient Map 8.25. Rotate Colors
 Report an error in Bugzilla  12.8. Paper Tile 12. 8. Paper Tile 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 8. Paper Tile 12. 8. 1. Overview Figure 17. 266. “ Papertile ” filter example. Original image
Filter “ Papertile ” applied
This filter cuts the image ( active layer or selection) into several
pieces, with square form, and then slides them so that they, more or
less, overlap or move apart. They can go out image borders a little.
 12. 8. 2. Activate the filter
You can find this filter through
Filters → Map → Paper Tile .  12. 8.3. Options Figure 17. 267. “ Paper Tile ” filter options Division X , Y and
Size parameters are linked, because filter starts
cutting image before it displaces pieces; so, piece size and
number of pieces in horizontal (X) and vertical (Y) directions
must be convenient to image size.
Movement Max (%)
This is the maximum displacement percentage against the side
size of squares.
Wrap around
As tiles move, some can go out image borders . If this option
is checked , what goes out on one side goes in on the
opposite side.
Fractional Pixels
Because of image cutting, original pixels can persist. There are
three ways treating them:
Background
Remaining pixels will be replaced with the background type
defined in the following section.
Ignore Background Type option is not taken
into account and remaining pixels are kept.
Force
Remaining pixels will be cut also.
Background Type
You can select the background type which will be used, if the
Background radio-button is checked, among
six options:
Transparent
Background will be transparent.
Inverted image
Background colors will be inverted (255-value in every color
channel).
Image
Background colors will be unchanged. The original image is
the background.
Foreground color
Remaining pixels will be replaced by the Foreground color of
Toolbox.
Background color
Remaining pixels will be replaced by the Background color of
Toolbox.
Select here
When this radio-button is checked, clicking in the color
dwell will open a Color Selector where you can select the
color you want for background.
Centering
If this option is checked , tiles will rather be gathered together
in the center of the image .
12.7. Map Object 12. 9. Small Tiles
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10. 8. Photocopy 10.8. Photocopy 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 8. Photocopy 10. 8. 1. Overview Figure 17. 193. Example for the “ Photocopy ” filter Original image Filter “ Photocopy ” applied
The Photocopy filter modifies the active layer or selection so that it
looks like a black and white photocopy, as if toner transferred was
based on the relative darkness of a particular region. This is achieved
by darkening areas of the image which are measured to be darker than a
neighborhood average, and setting other pixels to white.
Tip
You may use this filter to sharpen your image. Create a copy of
the active layer and use the filter on the copy. Set the
Layer Mode to
Multiply and adjust the opacity slider
to get the best result.
10. 8. 2. Starting filter
You can find this filter from the image menu through
Filters → Artistic → Photocopy .
10. 8.3. Options Figure 17. 194. “ Photocopy ” filter options Preview
Your changes are displayed in this preview before being applied
to your image.
Mask radius
This parameter controls the size of the pixel neighbourhood over
which the average intensity is computed and then compared to each
pixel in the neighborhood to decide whether or not to darken it.
Large values result in very thick black areas bordering the
regions of white and much less detail for black areas. Small
values result in less toner overall and more details everywhere.
Sharpness
With this option, you can set photocopy sharpness, from 0.0 to
1.0 .
Percent black
This parameter controls the amount of black color added to the
image. Small values make the blend from color regions to blackened
areas smoother and dark lines themselves thinner and less
noticeable. Larger values make the lines thicker, darker and
sharper. The maximum value makes the lines aliased. The best, most
natural results are usually achieved with an intermediate value.
Values vary from 0.0 to 1.0 .
Percent white
This parameter increases white pixels percentage.
10.7. Oilify 10.9. Predator
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2. 6. Pixelise 2.6. Pixelise 2. Blur Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 6. Pixelise 2. 6. 1. Overview Figure 17. 16. Example for the “ Pixelize ” filter Original “ Pixelize ” applied
The Pixelize filter renders the image using large color blocks. It is
very similar to the effect seen on television when obscuring a
criminal during trial. It is used for the “ Abraham Lincoln
effect ” : see [ BACH04 ] .
 2. 6. 2. Activate the filter
You can find this filter in the image menu through
Filters → Blur → Pixelise  2. 6.3. Options Figure 17. 17. “ Pixelize ” filter options Pixel width, Pixel height
Here you can set the desired width and height of the blocks.
By default, width and height are linked, indicated by the chain
symbol next to the input boxes. If you want to set width and
height separately, click on that chain symbol to unlink them.
Using the unit selection box you can select the unit of measure
for height and width.
2.5. Motion Blur 2. 7. Tileable Blur  Report an error in Bugzilla  13. 4. Plasma 13.4. Plasma 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 4. Plasma 13. 4. 1. Overview Figure 17. 284. Example of a rendered plasma Filter “ Plasma ” applied
All of the colors produced by Plasma are completely saturated.
Sometimes the strong colors may be distracting, and a more
interesting surface will appear when you desaturate the image
using
Colors → Desaturate .
 13. 4. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Clouds → Plasma .  13. 4.3. Options Figure 17. 285.  “ Plasma ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview.  Random seed
This option controls the randomization element. The
Randomize check-button will set the seed
using the hardware clock of the computer. There is no reason to
use anything else unless you want to be able to repeat the exact
same pattern of randomization on a later occasion.
Turbulence
This parameter controls the complexity of the plasma.
High values give a hard feeling to the cloud (like an
abstract oil painting or mineral grains), low values
produce a softer cloud (like steam, mist or smoke). The
range is 0.1 to 7.0.
13.3. Fog 13.5. Solid Noise
 Report an error in Bugzilla  12.6. Plug-In Browser 12.6. Plug-In Browser 12. The “ Help ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 6. Plug-In Browser
The Plug-In Browser command displays a
dialog window which shows all of the extensions (plug-ins) which are
currently loaded in GIMP , both as a list and
as a hierarchical tree structure. Since many of the filters are actually
plug-ins, you will certainly see many familiar names here. Please note
that you do not run the extensions from this dialog window. Use the
appropriate menu entry to do that instead. For example, you can run
filter plug-ins by using the Filter command
on the image menubar.
 12. 6. 1. Activating the Command
You can access this command from the image menubar through
Help → Plug-in Browser  12. 6. 2.
Description of the “ Plug-In Browser ” dialog window
Figure 16. 211.
The list view of the “ Plug-In Browser ” dialog window
The figure above shows the list view of the
Plug-In Browser . You can click on the name of
a plug-in in the scrolled window to display more information about
it. Select the List View by clicking
on the tab at the top of the dialog .
You can search for a plug-in by name by entering part or all of the
name in the Search: text box. The left part of
the dialog then displays the matches found.
Figure 16.212.
The tree view of the “ Plug-In Browser ” dialog window
The figure above shows the tree view of the
Plug-In Browser . You can click on the name of
a plug-in in the scrolled window to display more information about
it. You can click on the arrowheads to expand or contract parts of
the tree. Select the Tree View by clicking on
the tab at the top of the dialog .
You can search for a plug-in by name by entering part or all of the
name in the Search: text box. The left part of
the dialog then displays the matches found.
Note
Not everything in these huge dialog windows is visible at the same
time. Use the scroll bars to view their content.
12.5. About 12.7. The Procedure Browser  Report an error in Bugzilla 
4. 12. Polar Coords 4. 12. Polar Coords 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 12. Polar Coords 4. 12. 1. Overview Figure 17. 63. Example for Polar Coords filter Original image “ Polar Coords ” filter applied
It gives a circular or a rectangular representation of your image with
all the possible intermediates between both.
 4. 12. 2. Activating the filter
You can find this filter through
Filters → Distorts → Polar Coords .  4. 12.3. Options Figure 17. 64. “ Polar Coords ” filter options Preview
The result of your settings will appear in the Preview without
affecting the image until you click on OK . Circle depth in percent
Slider and input box allow you to set the "circularity" of the
transformation, from rectangle (0%) to circle (100%).
Offset angle
This option controls the angle the drawing will start from
(0 - 359°), and so turns it around the circle center.
Map backwards
When this option is checked , the drawing will start from the
right instead of the left.
Map from top
If unchecked, the mapping will put the bottom row in the middle
and the top row on the outside. If checked, it will be the
opposite.
To polar
If unchecked, the image will be circularly mapped into a rectangle
(odd effect). If checked, the image will be mapped into a circle.
4.12.4. Examples Figure 17.65. With text
If you have just written the text, you must Flatten the
image before using the filter.
Figure 17.66. With two horizontal bars 4.11. Page Curl 4. 13. Ripple
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13. 14. Qbist 13.14. Qbist 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 14. Qbist 13. 14. 1. Overview Figure 17. 316. Applying examples for the Qbist filter
The Qbist filter generates random textures containing geometric figures
and color gradients.
 13. 14. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Pattern → Qbist  13. 14.3. Options Figure 17. 317. “ Qbist ” filter options
The Qbist filter generates random textures . A starting texture is
displayed in the middle square, and different variations surround it. If
you like one of the alternative textures, click on it. The chosen
texture now turns up in the middle, and variations on that specific
theme are displayed around it. When you have found the texture you want,
click on it and then click OK. The texture will now appear on the
currently active layer, completely replacing its previous contents.
Antialiasing
If you check this, it will make edges appear smooth rather than
stair-step-like.
Undo Lets you go back one step in history. Open, Save
These buttons allow you to save and reload your textures. This is
quite handy because it's almost impossible to re-create a good
pattern by just clicking around.
13.13. Maze 13.15. Sinus
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6. 3. Hurl 6.3. Hurl 6. Noise Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 3. Hurl 6. 3. 1. Overview Figure 17. 128. Example for the “ Hurl ” filter Original image Filter “ Hurl ” applied
You can find this filter through
Filters → Noise → Hurl .
The Hurl filter changes each affected pixel to a random color, so it
produces real random noise . All color channels,
including an alpha channel (if it is present) are randomized. All
possible values are assigned with the same probability. The original
values are not taken into account . All or only some pixels in an active
layer or selection are affected, the percentage of affected pixels is
determined by the Randomization (%) option.
6.3.2. Options Figure 17.129.  “ Hurl ” options Random seed
Controls randomness of hurl. If the same random seed in the
same situation is used, the filter produces exactly the same
results. A different random seed produces different
results. Random seed can be entered manually or generated
randomly by pressing New Seed button.
When the Randomize option is checked, random
seed cannot be entered manually, but is randomly generated each
time the filter is run. If it is not checked, the filter remembers
the last random seed used.  Randomization (%)
This slider represents the percentage of pixels of the active
layer or selection which will be hurled. The higher value, the
more pixels are hurled.
Repeat
It represents the number of times the filter will be
applied. In the case of the Hurl filter it is not very useful,
because the same results can be obtained faster just by using a
higher Randomization (%) value.
6.2. HSV Noise 6. 4. Pick
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6. 4. Pick 6.4. Pick 6. Noise Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 4. Pick 6. 4. 1. Overview Figure 17. 130. Example of applying the “ Pick ” filter Original image Filter “ Pick ” applied
The Pick filter replaces each affected pixel by a pixel value randomly
chosen from its eight neighbours and itself (from a 3×3 square the pixel
is center of). All or only some pixels in an active layer or selection
are affected, the percentage of affected pixels is determined by the
Randomization (%) option.
 6. 4. 2. Activate the filter
You can find this filter through
Filters → Noise → Pick .  6. 4.3. Options Figure 17. 131.  “ Pick ” filter options Random seed
Controls randomness of picking. If the same random seed in the
same situation is used, the filter produces exactly the same
results. A different random seed produces different
results. Random seed can be entered manually or generated
randomly by pressing New Seed button.
When the Randomize option is checked, random
seed cannot be entered manually, but is randomly generated each
time the filter is run. If it is not checked, the filter remembers
the last random seed used.  Randomization (%)
This slider represents the percentage of pixels of the active
layer or selection which will be picked. The higher value, the
more pixels are picked.
Repeat
This slider represents the number of times the filter will be
applied. Higher values result in more picking, pixel values
being transferred farther away.
6.3. Hurl 6.5. RGB Noise
 Report an error in Bugzilla  6. 6. Slur 6.6. Slur 6. Noise Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 6. Slur 6. 6. 1. Overview Figure 17. 134. Example of applying the Slur filter Original image Filter “ Slur ” applied
Slurring produces an effect resembling melting the image downwards; if a
pixel is to be slurred, there is an 80% chance that it is replaced by
the value of a pixel directly above it; otherwise, one of the two pixels
to the left or right of the one above is used. All or only some pixels
in an active layer or selection are affected, the percentage of affected
pixels is determined by the Randomization (%)
option.
 6.6. 2. Activate the filter
You can find this filter through
Filters → Noise → Slur .  6. 6.3. Options Figure 17. 135.  Slur filter options Random seed
It controls randomness of slurring. If the same random seed in
the same situation is used, the filter produces exactly the
same results. A different random seed produces different
results. Random seed can be entered manually or generated
randomly by pressing New Seed button.
When the Randomize option is checked, random
seed cannot be entered manually, but is randomly generated each
time the filter is run. If it is not checked, the filter remembers
the last random seed used.  Randomization (%)
This slider represents the percentage of pixels of the active
layer or selection which will be slurred. The higher value, the
more pixels are slurred, but because of the way the filter
works, its effect is most noticeable if this slider is set to a
medium value, somewhere around 50. Experiment with it and try
for yourself!
Repeat
This slider represents the number of times the filter will be
applied. Higher values result in more slurring, moving the
color over a longer distance.
6.5. RGB Noise 6. 7. Spread
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8. 17. Recompose 8.17. Recompose 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 17.2. Activate the command
This command is found in the image window menu under
Colors → Components → Recompose :
This command is active after using Decompose.  8. 16.
Decompose
8. 18. The “ Map ” Submenu  Report an error in Bugzilla  3. 7. Red Eye Removal 3.7. Red Eye Removal 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 7. Red Eye Removal 3. 7. 1. Overview Figure 17. 27. Example for the “ Red Eye Removal ” filter Original image “ Red Eye Removal ” applied
The aim of this filter is - guess what - to remove red eyes from an
image. Before applying the “ Red Eye Removal ”
you must do a selection (lasso or elliptical) of the boundary of the
iris of the eye (s) having a red pupil. After only you can apply the
filter on this selection. If you don't make this selection, the filter
inform you that :
“ Manually selecting the eyes may improve the results ” .
 3. 7. 2. Activating the filter
This filter is found in the image window menu under
Filters → Enhance → Red Eye Removal .  3. 7.3. Options Figure 17. 28. “ Red Eye Removal ” options Preview
If you check “ Preview ”
you can see the modifications in real-time in the preview
window. And you can choose the good value of threshold compared
with what you see, and then validate it.
Threshold
If you move the cursor of threshold the amount of red color to
eliminate will vary.
3.6. NL Filter 3.8. Sharpen
 Report an error in Bugzilla  8. 38. Retinex 8.38. Retinex 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 38. 2. Activate the filter
This filter is found in the image window menu under
Colors → Retinex .  8. 38.3. Options Figure 16.199. “ Retinex ” filter options
These options call for notions that only mathematicians and imagery
engineers can understand. In actual practice, the user has to grope
about for the best setting. However, the following explanations should
help out the experimented GIMP user.
Level
Here is what the plug-in author writes on his site
[ PLUGIN-RETINEX ] :
“ To characterize color variations and the lightor, we make
a difference between (gaussian) filters responses at different
scales. These parameters allow to specify how to allocate scale
values between min scale (sigma 2.0) and max (sigma equal to the
image size) ” ...
Uniform
Uniform tends to treat both low and high intensity areas
fairly.
Low
As a rule of thumb, low does “ flare up ”
the lower intensity areas on the image.
High
High tends to “ bury ” the lower intensity
areas in favor of a better rendering of the clearer areas
of the image.
Scale
Determines the depth of the Retinex scale. Minimum value is 16, a
value providing gross, unrefined filtering. Maximum value is 250.
Optimal and default value is 240.
Scale division
Determines the number of iterations in the multiscale Retinex
filter. The minimum required, and the recommended value is three.
Only one or two scale divisions removes the multiscale aspect and
falls back to a single scale Retinex filtering. A value that is
too high tends to introduce noise in the picture.
Dynamic
As the MSR algorithm tends to make the image lighter, this slider
allows you to adjust color saturation contamination around the
new average color. A higher value means less color saturation.
This is definitely the parameter you want to tweak for optimal
results, because its effect is extremely image-dependent.
8.37. Max RGB 9. The “ Tools ” Menu  Report an error in Bugzilla 
6. 5. RGB Noise 6. 5. RGB Noise 6. Noise Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 5. RGB Noise 6. 5. 1. Overview Figure 17. 132. Example of applying the “ RGB Noise ” filter Original image Filter “ RGB Noise ” applied
The RGB Noise filter adds a normally distributed noise to a layer or a
selection. It uses the RGB color model to produce the noise (noise is
added to red, green and blue values of each pixel ). A normal
distribution means, that only slight noise is added to the most pixels
in the affected area, while less pixels are affected by more extreme
values. (If you apply this filter to an image filled with a solid grey
color and then look at its histogram, you will see a classic bell-shaped
Gaussian curve.)
The result is very naturally looking noise.
This filter does not work with indexed images.
 6. 5. 2. Activate the filter
You can find this filter through
Filters → Noise → RGB Noise .  6. 5.3. Options Figure 17. 133. “ RGB Noise ” filter options Preview
This preview displays interactively changes before they are
applied to the image.
Correlated noise
Noise may be additive (uncorrelated) or multiplicative (correlated
- also known as speckle noise). When checked, every channel value
is multiplied by an normally distributed value. So the noise
depends on the channel values: a greater channel value leads to
more noise, while dark colors (small values) tend to remain dark.
Independent RGB
When this radio button is checked, you can move each RGB slider
separately. Otherwise, sliders R, G and B will be moved all
together. The same relative noise will then be added to all
channels in each pixel, so the hue of pixels does not change much.
Red, Green, Blue, Alpha
These slidebars and adjacent input boxes allow to set noise level
(0.00 - 1.00) in each channel. Alpha channel is only
present if your layer holds such a channel. In case of a grayscale
image, a Grey is shown instead of color
sliders.
The value set by these sliders actually determine the standard
deviation of the normal distribution of applied noise. The used
standard deviation is a half of the set value (where 1 is the
distance between the lowest and highest possible value in a
channel).
6.4. Pick 6.6. Slur
 Report an error in Bugzilla 
4. 13. Ripple 4.13. Ripple 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 13. Ripple 4. 13. 1. Overview Figure 17. 67. “ Ripple ” filter example Original image Filter “ Ripple ” applied
It displaces the pixels of the active layer or selection to waves or
ripples reminding a reflection on disturbed water.
 4. 13. 2. Activating the filter
You can find this filter through
Filters → Distorts → Ripple .  4. 13.3. Options Figure 17. 68. “ Ripple ” filter options Preview
The result of your settings will appear in the Preview without
affecting the image until you click on OK . Options Antialiasing
This improves the scaled look the image borders may have.
Retain tileability
This preserves the seamless properties if your image is a tile pattern.
Orientation
That's the Horizontal or
Vertical direction of waves.
Edges
Because ripples cause pixel displacement, some pixels may be
missing on the image sides:
With Wrap , pixels going out one side
will come back on the other side , replacing so the missing
pixels.
With Smear , the adjacent pixels will
spread out to replace the mixing pixels.
With Blank , the missing pixels will be
replaced by black pixels, if the layer does not have an
Alpha channel . If an Alpha channel exists in the layer,
transparent pixels replace the missing pixels after applying
this option.
Wave Type
Choose how the wave should look like:
Sawtooth Sine Period
It is related to wavelength (0-200 pixels)
Amplitude
It is related to wave height (0-200 pixels).
Phase shift
It is angle to delay the wave (0-360 degree).
Appling this filter again with the same setting
but Phase shift differs by 180 brings the once processed image
back to become almost similar to the first original image.
4.12. Polar Coords 4. 14. Shift
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8. 25. Rotate Colors 8.25. Rotate Colors 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 25. 2. Activating the filter
This filter is found in the image window menu under
Colors → Map → Rotate Colors .  8. 25.3. Main Options Figure 16.170.
Main Options of the “ Color Map Rotation ” filter
You have there two color circles, one for the “ From ”
color range and the other for the “ To ” color range:
From
The Color Circle : Two axis to define
“ From ” range. The curved arrow in angle lets to
recognise “ From ” axis and “ To ”
axis of range. Click-drag these axis to change range.
Switch to Clockwise/Counterclockwise :
Sets the direction the range is going.
Change Order of Arrows : Inverts From and
To axis. This results in an important color change as colors
in selection angle are different.
Select All selects the whole color
circle.
From and To boxes
display start axis and end axis positions (in rad/PI) which
are limiting the selected color range. You can enter these
positions manually or with help of arrow-heads.
To
This section options are the same as “ From ” section
ones.
8.25.4. Gray Options Figure 16.171. Base image for Gray Options
Three sectors are defined for Red, Green and Blue with different
saturations. Gray and White colors are represented (0% Sat).
In this tab, you can specify how to treat gray. By default, gray is not
considered as a color and is not taken in account by the rotation. Here,
you can convert slightly saturated colors into gray and you can also
convert gray into color.
Gray Color Circle
At center of this color circle is a small “ define
circle ” . At center, it represents gray. If you increase
gray threshold progressively, colors with saturation less than
this threshold turn to gray.
Then, if you pan the define circle in the color circle, or if
you use input boxes, you define
Hue and
Saturation . This color will replace all colors you
have defined as gray. But result depends on Gray Mode too.
Gray Mode
The radio buttons Treat As This
and Change As This
determine how your previous choices will be
treated:
With Change to this ,
gray will take the color defined by the define circle
directly, without any rotation, whatever its position in
the color circle.
With Treat as this ,
gray will take the color defined by the define circle
after rotation, according to “ From ” and
“ To ” choices you made in the Main tab. With
this option, you can select color only in the
“ From ” sector, even if it is not visible in
Gray tab.
Figure 16.172. Gray Mode
The small circle is on yellow and mode is “ Change to
this ” . Blue has changed to yellow. Note that
Gray and White did so too.
Gray Threshold Figure 16.173. Gray Threshold
Gray-threshold is 0.25: the blue sector (sat 0.25) has
turned to Gray ( Note that Gray and White , that are 0% Sat.,
are not concerned).
You specify there how much saturation will be considered gray.
By increasing progressively saturation, you will see an
enlarging circle in color circle and enlarging selected areas in
Preview if “ Continuous update ” is checked. In a
black to white gradient , you can see enlarging color replacement
as you increase threshold very slowly.
Black to White gradient, progressively filled with color, as
threshold increases.
8.25.5. Previews Original, Rotated
The Original preview displays a thumbnail of the original image
and the Rotated preview displays color changes interactively,
before they are applied to the Image.
Continuous Update Continuous Update displays color changes
continuously in the Rotated preview.
Area
In this drop down list, you can select between
Entire Layer : works on the whole
layer (The image if there is no selection ).
Selection : displays selection only.
Context : displays selection in image
context.
8.25.6. Units
You can select here the angle unit used to locate colors in the
Hue/Saturation circle. This choice is valid only for the current filter
session: don't click on OK just after selecting unit, return to the
wanted tab!
8.24. Palette Map 8.26. Sample Colorize
 Report an error in Bugzilla  8. 26. Sample Colorize 8.26. Sample Colorize 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 26. 2. Activate the filter
This filter is found in the image window menu under
Colors → Map → Sample Colorize .  8. 26.3. Options Figure 16.175. Options of the “ Sample Colorize ” filter
The filter window is divided into two parts : Destination on the left,
Sampling on the right.
Destination, Sample
By default, displayed image previews reproduce the image you
invoked the filter from.
The sample can be the whole preview, or a
selection of this preview. With the drop list, you can select
another sample-image among the names of images present on
your screen when you called the filter. If you choose
From Gradient (or From Inverse
Gradient ), the selected gradient in Gradient Dialog
(or its inverse) will be the sample. It will be displayed into
the gradient bar below the sample preview . The sampling preview
is greyed out and two cursors allow you to select the gradient
range that will be applied to the image or selection.
Destination is, by default, the source
image. The drop list displays the list of images present on your
screen when you evoked the filter and allow you to select
another destination image. If there is a selection in this
image, it will be gray-scaled, else the whole preview will be
gray-scaled.
Show Selection
This option toggles between the whole image and the selection,
if it exists.
Show Colors
This option toggles between colors and gray-scale.
Get Sample Colors
When you click on this button, the gradient bar below the
sample preview displays colors of the sample. If your sample
holds few colors, transitions may be abrupt. Check
Smooth Sample Colors option to improve them.
Use Subcolors is more difficult to
understand. Let's say first that in a greyscale image there is
information only for Value (luminosity, more or less light). In a
RGB image, each pixel has information for the three colors and
Value. So, pixels with different color may have the same Value.
If this option is checked , colors will be mixed and applied to
Destination pixels having that Value. If it is unchecked, then
the dominating color will be applied.
Out Levels
Two input boxes and two sliders act the same: they limit the
color range which will be applied to destination image. You can
choose this range accurately. Result appears interactively in
destination preview.
In Levels
Three input boxes and three sliders allow to fix importance of
dark tones, mid tones and light tones. Result appears
interactively in destination preview.
Hold Intensity
If this option is checked , the average light intensity of
destination image will be the same as that of source image.
Original Intensity
If this option is checked , the In levels intensity settings will
not be taken in account: original intensity will be preserved.
8.25. Rotate Colors 8.27. The “ Info ” Submenu  Report an error in Bugzilla  2. 4. Selective Gaussian Blur 2.4. Selective Gaussian Blur 2. Blur Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 4. Selective Gaussian Blur 2. 4. 1. Overview Figure 17. 11. The Selective Gaussian Blur filter Original Blur applied
Contrary to the other blur plug-ins, the Selective Gaussian Blur plug-in
doesn't act on all pixels: blur is applied only if the difference
between its value and the value of the surrounding pixels is less than a
defined Delta value. So, contrasts are preserved because difference is
high on contrast limits. It is used to blur a background so that the
foreground subject will stand out better. This add a sense of depth to
the image with only a single operation.
 2. 4. 2. Activate the filter
You can find this filter in the image menu under
Filters → Blur → Selective Gaussian Blur  2. 4.3. Options Figure 17. 12.
“ Selective Gaussian ” filter parameters settings
Blur radius
Here you can set the blur intensity , in pixels.
Max. delta
Here you can set the maximum difference (0-255) between the
pixel value and the surrounding pixel values. Above this Delta,
blur will not be applied to that pixel.
2.3. Gaussian Blur 2.5. Motion Blur
 Report an error in Bugzilla  14. 3. Semi-Flatten 14.3. Semi-Flatten 14. Web Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  14. 3. Semi-Flatten 14.3. 1. Overview
The Semi-flatten filter helps those in need of a solution to
anti-aliasing indexed images with transparency. The GIF indexed format
supports complete transparency (0 or 255 alpha value), but not
semi-transparency (1 - 254): semi-transparent pixels will be
transformed to no transparency or complete transparency, ruining
anti-aliasing you applied to the logo you want to put onto your Web
page.
Before applying the filter, it's essential that you should know the
background color of your Web page. Use the color-picker to determine
the exact color which pops up as the Foreground color of the Toolbox.
Invert FG/BG colors so that BG color is the same as Web background
color.
Semi-flatten process will combine FG color to layer (logo) color,
proportionally to corresponding alpha values, and will rebuild correct
anti-aliasing. Completely transparent pixels will not take the color.
Very transparent pixels will take a few color and weakly transparent
will take much color.
 14. 3. 2. Activate the filter
You can access this filter in the image window menu through
Filters → Web → Semi-Flatten .  It is available if your image holds an Alpha channel
(see Section 7.33, “Add Alpha Channel” ).
Otherwise, it is greyed out.
14.3.3. Example
In the example below, the Toolbox Background color is pink, and the
image has feathered edges on a transparent background.
Figure 17.350. Semi-Flatten example Active background color At 800% zoom level
Full transparency is kept. Semi-tranparent pixels are colored with pink
according to their transparency (Alpha value). This image will well
merge into the pink background of the new page.
Figure 17.351. Semi-Flatten filter applied
Result, in GIF format, after applying Semi-flatten filter.
14.2. ImageMap 14.4. Slice
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3.8. Sharpen 3.8. Sharpen 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 8. Sharpen 3.8. 1. Overview
Most of digitized images need correction of sharpness. This is due to
digitizing process that must chop a color continuum up in points with
slightly different colors: elements thinner than sampling frequency
will be averaged into an uniform color. So sharp borders are rendered
a little blurred. The same phenomenon appears when printing color dots
on paper.
The Sharpen filter accentuates edges but also any noise or blemish and
it may create noise in graduated color areas like the sky or a water
surface. It competes with the Unsharp Mask filter, which is more
sophisticated and renders more natural results.
Figure 17.29. Applying example for the Sharpen filter Original image Filter “ Sharpen ” applied  3. 8. 2. Activating the filter
You can find this filter through
Filters → Enhance → Sharpen .  3. 8.3. Options Figure 17. 30.  “ Sharpen ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Sharpness
The slider and input boxes allow you to set sharpness (1-99)
and you can judge result in preview. By increasing sharpness,
you may increase image blemishes and also create noise in
graduated color areas .
3.7. Red Eye Removal 3. 9. Unsharp Mask
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4. 14. Shift 4.14. Shift 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 14. Shift 4. 14. 1. Overview Figure 17. 69. Example for the Shift filter Original image Filter “ Shift ” applied
It shifts all pixel rows, horizontally or vertically, in the current
layer or selection , on a random distance and within determined limits.
 4. 14. 2. Activating the filter
You can find this filter through
Filters → Distorts → Shift .  4. 14.3. Options Figure 17. 70. “ Shift ” filter options Preview
The result of your settings will appear in the Preview without
affecting the image until you click on OK . Shift horizontally, Shift vertically
This option sets the dimension where pixels are moved.
Pixels going out one side will come back on the other side .
Shift amount
With this option, you can set the maximum shift, between 1 and
200 pixels, or in another unit of measurement.
4.13. Ripple 4.15. Value Propagate
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13. 15. Sinus 13.15. Sinus 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 15. Sinus 13. 15. 1. Overview Figure 17. 318. Applying example for the Sinus filter Filter “ Sinus ” applied
You can find this filter from the image menu through
Filters → Render → Pattern → Sinus .
The Sinus filter lets you make sinusoidally based textures,
which look rather like watered silk or maybe plywood. This plug-in
works by using two different colors that you can define in the
Colors tab. These two colors then create wave patterns based on
a sine function.
You can set the X and Y scales, which determine how stretched or
packed the texture will be. You can also set the Complexity of
the function: a high value creates more interference or
repetition in the pattern. An example is shown below.
13.15.2. Options 13.15.2.1. Settings Figure 17.319. “ Sinus ” filter options ( Settings) Drawing Settings X scale, Y scale
A low X/Y value will maximize the horizontal/vertical
stretch of the texture, whereas a high value will compress
it.
Complexity
This controls how the two colors interact with each other
(the amount of interplay or repetition).
Calculation Settings Random seed
 This option controls the random
behaviour of the filter. If the same random seed in the
same situation is used, the filter produces exactly the
same results. A different random seed produces different
results. Random seed can be entered manually or generated
randomly by pressing the New Seed
button.
When the Randomize option is checked,
random seed cannot be entered manually, but is randomly
generated each time the filter is run. If it is not
checked, the filter remembers the last random seed used. 
Force tiling?
If you check this, you'll get a pattern that can be
used for tiling. For example, you can use it as a
background in an HTML page, and the tile edges will be
joined seamlessly.
Ideal, Distorted
This options give additional control of the interaction between
the two colors. “ Distorted ” creates a more
distorted interference between the two colors than
“ Ideal ” .
13.15.2.2. Colors Figure 17.320. “ Sinus ” filter options ( Colors) Colors
Here, you set the two colors that make up your texture. You can
use Black & white or the
Foreground & background colors in the
toolbox, or you can Choose a color with the
color icons.
Alpha Channels
This sliders allow you to assign an opacity to each of the
colors. ( If the layer you are working on does not have an alpha
channel, they will be grayed out.)
13.15.2.3. Blend Figure 17.321. “ Sinus ” filter options ( Blend) Gradient
You can choose between three functions to set the shapes of the
waves that are produced: Linear, Bilinear and Sinusoidal.
Exponent
The Exponent controls which of the two colors is dominant, and
how dominant it is. If you set the exponent to -7.5, the left
color will dominate totally, and if you set it to +7.5 it will
be the other way around. A zero value is neutral.
13.14. Qbist 13.16. Circuit
 Report an error in Bugzilla  12. 9. Small Tiles 12. 9. Small Tiles 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 9. Small Tiles 12. 9. 1. Overview Figure 17. 268. Example for the “ Small Tiles ” filter Original image
This filter reduces the image ( active layer or selection) and
displays it in many copies inside the original image.
 12. 9. 2. Activate the filter
You can find this filter through
Filters → Map → Small Tiles .  12. 9.3. Options Figure 17. 269. “ Small Tiles ” filter options Flip
You can flip tiles according to the
Horizontal or/and
Vertical axis by checking the corresponding
option(s).
You can also decide which tiles will be flipped:
All tiles
No comment.
Alternate tiles
Only odd tiles will be flipped.
Explicit tile
You can define a particular tile using both
Row and Column
input boxes. This tile will be marked with a box in
Preview. Press Apply to mark this
explicit tile. Repeat this procedure to mark more than one
tile.
Opacity
With this slider and its input box, you can set the opacity of
the resulting image. This option is valid only if your image has
an Alpha channel .
Number of Segments n² means “ the image into n to
the power of two tiles ” , where “ n ” is the
number you set with the slider or its input box. n = 3 will
make nine tiles in the image.
12.8. Paper Tile 12. 10. Tile
 Report an error in Bugzilla  8. 31. Smooth Palette 8.31. Smooth Palette 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 31. 2. Activating the filter
This filter is found in the image window menu under
Colors → Info → Smooth Palette .  8. 31.3. Options Figure 16.184. “ Smooth Palette ” options Parameter Settings
You can set palette dimensions for Width and
Height . Dimensions are linked when chain is
not broken. You can also select unit.
Search Depth
Increasing Search Depth (1 - 1024) will result in more shades in
palette.
8.30. Colorcube Analysis 8.32. The Color Filters  Report an error in Bugzilla  7. 6. Sobel 7.6. Sobel 7. Edge-Detect Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 6. Sobel 7. 6. 1. Overview Figure 17. 148. Applying example of the Sobel filter Original image Filter “ Sobel ” applied
Sobel's filter detects horizontal and vertical edges separately on a
scaled image. Color images are turned into RGB scaled images. As with
the Laplace filter, the result is a transparent image with black lines
and some rest of colors.
 7. 6. 2. Activating the filter
You can find this filter through
Filters → Edge-Detect → Sobel .  7. 6.3. Options Figure 17. 149.  Sobel filter options Preview
If checked, changes in the image are displayed in the Preview in
real time before being applied to the image. 
Sobel horizontally Renders near horizontal edges. Sobel vertically Renders near vertical edges. Keep sign of result
This option allows you to set how the filter will work if you have
selected one direction for use only: a flat relief with bumps and
hollows will be created.
7.5. Neon 8. Generic Filters
 Report an error in Bugzilla  10. 10. Softglow 10.10. Softglow 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 10. Softglow 10. 10. 1. Overview Figure 17. 200. Example for the “ SoftGlow ” filter Original image Filter “ Softglow ” applied
This filter lights the image with a soft glow. Softglow produces this
effect by making bright areas of the image brighter.
10. 10. 2. Starting filter
You can find this file in the Image menu through:
Filters → Artistic → Softglow .
10. 10.3. Options Figure 17. 201. “ Softglow ” filter options Preview
Your changes are displayed in this preview before being applied
to your image.
Glow radius
The glow radius parameter controls the sharpness of the effect,
giving a "vaseline-on-the-lens" effect.
Brightness
The brightness parameter controls the degree of intensification
applied to image highlights.
Sharpness
The sharpness parameter controls how defined or alternatively
diffuse the glow effect should be.
10.9. Predator 10.11. Van Gogh (LIC)  Report an error in Bugzilla  13. 5. Solid Noise 13. 5. Solid Noise 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 5. Solid Noise 13. 5. 1. Overview Figure 17. 286. Example of turbulent solid noise Filter “ Solid noise ” applied
Solid Noise is a great texture maker. Note that this noise is
always gray, even if you applied it to a very colorful image (it
doesn't matter what the original image looks like -- this filter
completely overwrites any existing background in the layer it is
applied to). This is also a good tool to create displacement maps for
the Warp plug-in or for the
Bump Map plug-in . With the
"turbulence" setting active, the results look quite a bit like real
clouds.
 13. 5. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Clouds → Solid noise .  13. 5.3. Options Figure 17. 287. “ Solid Noise ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Random seed
 This option controls random behaviour of the filter. If the same
random seed in the same situation is used, the filter produces
exactly the same results. A different random seed produces
different results. Random seed can be entered manually or
generated randomly by pressing New Seed
button.
When the Randomize option is checked, random
seed cannot be entered manually, but is randomly generated each
time the filter is run. If it is not checked, the filter remembers
the last random seed used.  Turbulent
If you check this, you'll get very interesting effects,
often something that looks much like oil on water, or
clouds of smoke, or living tissue, or a Rorschach blot.
Detail
This controls the amount of detail in the noise
texture. Higher values give a higher level of detail, and
the noise seems to be made of spray or small particles,
which makes it feel hard. A low value makes it more soft
and cloudy.
Tileable
If you check Tileable, you'll get a noise which can be
used as tiles. For example, you can use it as a background
in an HTML page, and the tile edges will be joined
seamlessly.
X size, Y size
These control the size and proportion of the noise shapes
in X (horizontal) and Y (vertical) directions (range 0.1
to 16.0).
13.4. Plasma 13.6. Flame
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5. 5. Sparkle 5.5. Sparkle 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 5. Sparkle 5. 5. 1. Overview Figure 17. 106. Applying example for the Sparkle filter Original image Filter “ Sparkle ” applied
This filter adds sparkles to your image. It uses the lightest points
according to a threshold you have determined. It is difficult to foresee
where sparkles will appear. But you can put white points on your image
where you want sparkles to be.
 5. 5. 2. Activate the filter
This filter is found in the image window menu under
Filters → Light and Shadow → Sparkle .  5. 5. 3. Parameter Settings Figure 17. 107.  “ Sparkle ” filter options
Sliders and input boxes allow you to set values.
Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Luminosity threshold
The higher the threshold, the more areas are concerned by
sparkling (0.0-0.1).
Flare intensity
When this value increases, the central spot and rays widen
(0.0-1.0).
Spike length
This is ray length (1-100). When you reduce it, small spikes
decrease first.
Spike points
Number of starting points for spikes (0-16). It's the number of
big spikes. There is the same number of small spikes. When
number is odd, small spikes are opposite the big ones. When
number is even, big spikes are opposite another big spike.
Spike angle
This is angle of first big spike with horizontal (-1 +360). -1
determines this value at random. If a spot has several pixels
within required threshold, each of them will generate a
sparkle. If angle is positive, they will all be
superimposed. With -1, each sparkle will have a random rotation
resulting in numerous thin spikes.
Spike density
This option determines the number of sparkles on your image. It
indicates the percentage (0.0-1.0) of all possible sparkles that
will be preserved.
Transparency
When you increase transparency (0.0-1.0), sparkles become more
transparent and the layer beneath becomes visible. If there is no
other layer, sparkle saturation decreases.
Random hue
This option should change sparkle hue at random... (0.0-1.0).
Random saturation
This option should change sparkle saturation at random...
(0.0-1.0).
Preserve luminosity
Gives to all central pixels the luminosity of the brightest pixel,
resulting in increasing the whole sparkle luminosity.
Inverse
Instead of selecting brightest pixels in image, Sparkle will
select the darkest ones, resulting in dark sparkles.
Add border
Instead of creating sparkles on brightest pixels, this option
creates an image border made up of numerous sparkles.
Natural color, Foreground color, Background color
You can change there the color of central pixels. This color will
be added in Screen mode (Multiply if Inverse
is checked). “ Natural color ” is the color of the
pixel in the image.
5.4. Lighting Effects 5. 6. Supernova
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13. 21. Sphere Designer 13.21. Sphere Designer 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 21. Sphere Designer 13.21. 1. Overview Figure 17.339.
The same image, before and after the application of
“ Sphere Designer ” filter .
Original image Filter “ Sphere Designer ” applied
This filter creates a three dimensional sphere with different textures.
It replaces the original image.
 13. 21.2. Activating Sphere Designer
You can find this filter through
Filters → Render → Sphere Designer .  13. 21.3. Options Figure 17.340. “ Sphere Designer ” filter parameters Preview
All your setting changes will appear in the Preview without
affecting the image until you click on OK .
Note that the preview displays the whole image, even if the
final result will concern a selection. Click the button
Update Preview to see the result of the
current settings.
Textures
The list of textures applied to the sphere. There textures are applied
in the order listed. Each item shows the type and the name of the
texture.
New
Creates a new texture and adds it to the end of the list . The name
and the features of this new texture are the ones which are
displayed in the Texture Properties area, but you can change them
by operating in this area, provided that your new texture is
highlighted.
Duplicate
Copies the selected texture and adds the copy to the end of the
list .
Delete
Deletes the selected texture from the list.
Open, Save
Allows to save current settings or load previously saved settings.
Properties Type Determines the type of action on the sphere. Texture Covers the sphere with a specific pattern. Bumpmap Gives some relief to the texture. Light
Lets you set the parameters of the light shining on the
sphere.
Texture
Determines the pattern used by the texture type. If the texture
applies to light then the light is distorted by this texture as if
it was going through this texture before falling onto the sphere.
If the texture applies to the texture itself, the texture is
applied directly to the sphere. Several options are available.
Colors
Sets the two colors to be used for a texture. By pressing the
color button a color selection dialog appears.
Scale
Determines the size of separate elements composing the texture.
For example, for the “ Checker ” texture this parameter
determines the size of black and white squares. Value range is
from 0 to 10.
Turbulence
Determines the degree of texture distortion before applying the
texture to the sphere. Value range is from 0 to 10. With values of
up to 1.0 you can still make out the undistorted patterns; beyond
that the texture gradually turns into noise.
Amount
Determines the degree of influence the texture has on the final
result. Value range is from 0 to 1. With the value of 0 the
texture does not affect the result.
Exponent
With the Wood texture, this options gives an aspect of venetian
blind, more or less open.
Transformations Scale X, Scale Y, Scale Z
Determines the degree of stretching/compression of the texture on
the sphere along the three directions. The value range is from 0
to 10.
Rotate X, Rotate Y, Rotate Z
Determines the amount of a turn of the texture on the sphere
around the three axes. The value range is from 0 to 360.
Position X, Position Y, Position Z
Determines the position of the texture relative to the sphere.
When type is Light, this parameter refers to the position of the
light floodlighting the sphere.
The Reset button sets all parameters to the
default values.
13.20. Line Nova 13.22. Spyrogimp
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6. 7. Spread 6.7. Spread 6. Noise Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 7. Spread 6. 7. 1. Overview Figure 17. 136. Example of applying the Spread filter Original image Filter “ Spread ” applied
The Spread filter swaps each pixel in the active layer or selection with
another randomly chosen pixel by a user specified amount. It works on
color transitions, not on plain color areas. No new color is introduced.
 6. 7. 2. Activate the filter
You can find this filter through
Filters → Noise → Spread .  6. 7.3. Options Figure 17. 137. “ Spread ” filter options Preview
This preview displays interactively changes before they are
applied to the image.
Spread Amount
You can set the distance that pixels will be moved along
Horizontal and
Vertical axis. The axis can be locked by
clicking the Chain icon. You can also define the Unit to be
used.
6.6. Slur 7. Edge-Detect Filters
 Report an error in Bugzilla  7. 37. Threshold Alpha 7.37. Threshold Alpha 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 37. Threshold Alpha
The Threshold Alpha command converts
semi- transparent areas of the active layer into completely transparent or
completely opaque areas, based on a threshold you set, between 0 and
255. It only works on layers of RGB images which have an alpha
channel. If the image is Grayscale or Indexed, or if the layer does not
have an alpha channel , the menu entry is insensitive and grayed out.
If the Keep transparency option is checked in the
Layers dialog, the command displays an error message.
 7. 37. 1. Activating the Command
You can access this command from the image menubar through
Layer → Transparency → Threshold Alpha .  7. 37. 2. Description of the Dialog Window Figure 16. 101.
The only one option of the “ Threshold Alpha ” dialog
Threshold
You can set the transparency value to be used as a threshold by
using the slider or by entering a value between 0 and 255 in
the input box. All transparency values above this threshold will
become opaque and all transparency values below or equal to this
threshold will become completely transparent. The transition is
abrupt.
Note
This command will never make completely transparent pixels
(alpha value = 0) opaque.
Figure 16.102. Threshold Alpha example
A transparency gradient 0-255.
Threshold set to 50, 127, 210.
7.36. Semi-flatten 7.38. Alpha to Selection
 Report an error in Bugzilla  12. 10. Tile 12.10. Tile 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 10. Tile 12. 10. 1. Overview Figure 17. 270. The same image, before and after applying Tile filter Original image (We have reduced image size intentionally)
This filter makes several copies of the original image, in a same or
reduced size, into a bigger (new) image.
 12. 10. 2. Activate the filter
You can find this filter through
Filters → Map → Tile .  12. 10.3. Options Figure 17. 271. “ Tile ” filter options Tile to New Size Width, Height
Input boxes and their arrow-heads allow you to enter the
dimensions for the new image. Both directions are linked by
default with a chain
.
You can make them independent by breaking
this chain. You can choose a unit else than pixel by clicking on
the drop-down list button .
The new image must be bigger than the original
one . Else, you will get an image sample only. Choose
sizes which are multiple of original sizes if you don't want to
have truncated tiles.
Create new image
It's in your interest to keep this option checked to avoid
modifying your original image.
12.9. Small Tiles 12. 11. Warp
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3. 22. Units 3.22. Units 3. The “ Edit ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 22. Units
The Units command displays a dialog
which shows information about the units of measurement that are
currently being used by GIMP . It also
allows you to create new units which can be used by
GIMP in a variety of situations .
 3. 22. 1. Activate the Command
You can access this command from the image menubar through
Edit → Units .  3. 22. 2. Description of the “ Unit Editor ” dialog window Figure 16. 24. The “ Unit Editor ” dialog window
The figure above shows the “ Unit Editor ” dialog window .
The list shows the units of measurement which are currently defined.
You can click on the New button or the
Duplicate button to create a new measurement
unit, as described below.
Description of the list elements Saved :
If this column is checked, a unit definition will be saved when
GIMP exits.
Some units are always kept, even if they are not marked with a
check. These are highlighted in the list.
ID :
The string GIMP uses to identify
the unit in its configuration files.
Factor :
How many units make up an inch.
Digits :
This field is a hint for numerical input fields. It specifies
how many decimal digits the input field should provide to get
approximately the same accuracy as an “ inch ” input
field with two decimal digits.
Symbol :
The unit's symbol if it has one (e.g. " for inches). The unit's
abbreviation is used if doesn't have a symbol.
Abbreviation :
The unit's abbreviation (e.g. “ cm ” for centimeters).
Singular :
The unit's singular form, which
GIMP can use to display messages
about the unit.
Plural :
The unit's plural form, which
GIMP can use to display messages
about the unit.
3.22.3. Defining New Units Figure 16.25. The “ New Unit ” dialog Adding the new unit “ wilbers ”
You can display the dialog shown above by clicking on either the
New button or the Duplicate
button on the Unit Editor dialog. The input
fields on the dialog are described above.
If you click on the New button , most input fields
are empty. If you click on the Duplicate button,
the values initially displayed in the input fields of the dialog are the
values of the unit you have currently selected in the
Unit Editor dialog. You can then edit the
values to create your new unit.
3.21. Modules 4. The “ Select ” Menu
 Report an error in Bugzilla  3. 9. Unsharp Mask 3.9. Unsharp Mask 3. Enhance Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  3. 9. Unsharp Mask 3. 9. 1. Overview Figure 17. 31. Applying example for the Unsharp Mask filter Original image Filter “ Unsharp mask ” applied
Out-of-focus photographs and most digitized images often need a
sharpness correction. This is due to the digitizing process that must
chop a color continuum up in points with slightly different colors:
elements thinner than sampling frequency will be averaged into an
uniform color. So sharp borders are rendered a little blurred. The same
phenomenon appears when printing color dots on paper.
The Unsharp Mask filter (what an odd name!) sharpens edges of the
elements without increasing noise or blemish. It is the king of the
sharpen filters.
Tip
Some imaging devices like digital cameras or scanners offer to sharpen
the created images for you. We strongly recommend you disable the
sharpening in this devices and use the GIMP filters instead. This way
you regain the full control over the sharpening of your images.
To prevent color distortion while sharpening, Decompose your image to
HSV and work only on Value. Then Compose the image to HSV. Go to
Colors → Components → Decompose... .
Make sure the Decompose to Layers
box is checked. Choose HSV and click OK. You will get a new grey-level
image with three layers, one for Hue, one for Saturation, and one for
Value. (Close the original image so you won't get confused). Select
the Value layer and apply your sharpening to it. When you are done,
with that same layer selected, reverse the process. Go to
Colors → Components → Compose... .
Again choose HSV and click OK. You will get back your original image
except that it will have been sharpened in the Value component.
 3. 9. 2. Activating the filter
You can find this filter through
Filters → Enhance → Unsharp Mask .  3.9.3. Options Figure 17. 32.  “ Unsharp Mask ” filter options Preview
If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.  Radius
The slider and input boxes (0.1-120) allow you to set how many
pixels on either side of an edge will be affected by sharpening.
High resolution images allow higher radius. It is better to always
sharpen an image at its final resolution.
Amount
This slider and input boxes (0 .00-5.00) allow you to set
strength of sharpening.
Threshold
This slider and input boxes (0 -255) allow you to set the minimum
difference in pixel values that indicates an edge where sharpen
must be applied. So you can protect areas of smooth tonal
transition from sharpening, and avoid creation of blemishes in
face, sky or water surface.
3.9.4. How does an unsharp mask work?
Using an unsharp mask to sharpen an image can seem rather weird. Here is
the explanation:
Think of an image with a contrast in some place. The intensity curve of
the pixels on a line going through this contrast will show an abrupt
increase of intensity: like a stair if contrast is perfectly sharp, like
an S if there is some blur.
Now, we have an image with some blur we want to sharpen (black curve).
We apply some more blur: the intensity variation will be more gradual
(green curve).
Let us subtract the blurredness intensity from the intensity of the
image. We get the red curve, which is more abrupt : contrast and
sharpness are increased. QED.
Unsharp mask has first been used in silver photography. The photograph
first creates a copy of the original negative by contact, on a film,
placing a thin glass plate between both; that will produce a blurred
copy because of light diffusion. Then he places both films, exactly
corresponding, in a photo enlarger, to reproduce them on paper. The dark
areas of the positive blurred film, opposed to the clear areas of the
original negative will prevent light to go through and so will be
subtracted from the light going through the original film.
In digital photography, with GIMP, you will go through the following
steps:
Open your image and duplicate it
Image → Duplicate
In the copy, duplicate the layer
Layer → Duplicate layer , then drop the Filters menu down and apply
Blur → Gaussian Blur
to the duplicated layer with the default IIR option and radius 5.
In the layer dialog of the duplicated image, change Mode to
“ Subtract ” , and in the right-clic menu, select
“ Merge down ” .
Click and drag the only layer you got into the original image, where
it appears as a new layer.
Change the Mode in this layer dialog to “ Addition ” .
Voilà. The “ Unsharp Mask ” plug-in does the same for you.
At the beginning of the curve, you can see a dip. If blurring is
important, this dip is very deep; the result of the subtraction can be
negative, and a complementary color stripe will appear along the
contrast, or a black halo around a star on the light background of a
nebula (black eye effect).
Figure 17.33. Black eye effect 3.8. Sharpen 4. Distort Filters
 Report an error in Bugzilla  4. 16. Video 4.16. Video 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 16. Video 4. 16. 1. Overview Figure 17. 80. Applying example for the “ Video ” filter Original image Filter “ Video ” applied
Apply low dot-pitch RGB simulation to the specified drawable.
 4. 16. 2. Activating the filter
You can find this filter through
Filters → Distorts → Video .  4. 16.3. Options Figure 17. 81. “ Video ” filter options Preview
This preview is unusual: Changes appear always on the same image
which is not yours.
Video Pattern
It would be rather difficult to describe what each pattern
will render. It's best to see what they render in the Preview.
Additive
Set whether the function adds the result to the original image.
Rotated Rotate the result by 90°. 4.15. Value Propagate 4. 17. Waves
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8. 4. Value Invert 8. 4. Value Invert 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 4. Value Invert 8. 4. 1. Overview Figure 16.122. Example for the “ Value invert ” filter Original image “ Value Invert ” applied
This filter inverts Value (luminosity) of the active layer or
selection . Hue and Saturation will not be affected, although the
color will sometimes be slightly different because of round-off
error. If you want to invert Hue and Saturation also, use
Colors → Invert .
Note that hue and saturation can be distorted quite a bit when
applying twice this filter for colors with a high luminosity (for
instance, HSV 102°,100%, 98%, a bright green, gives HSV 96°, 100%, 2%
after a first application of the filter , and 96°, 100%, 98% after a
second application). Thus, you should not expect to be able to apply
this filter twice in a row and get back the image you started with.
Figure 16.123. Example of using this filter twice Original image First application of the filter
Second application: the image is not exactly the same as the
original one.
 8. 4. 2. Activate the filter
You can access this command from the image menu bar through
Colors → Value Invert .  8. 3. Invert 8. 5. Use GEGL
 Report an error in Bugzilla  4. 15. Value Propagate 4. 15. Value Propagate 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 15. Value Propagate 4. 15. 1. Overview Figure 17. 71. Example for the Value Propagate filter Original image Filter “ Value Propagate ” applied
This filter works on color borders. It spreads pixels that differ in a
specified way from their neighbouring pixels.
 4. 15. 2. Activating the filter
This filter is found in the image window menu under
Filters → Distorts → Value Propagate .  4. 15.3. Options Figure 17. 72. “ Value propagate ” filter options Preview
The result of your settings will appear in the Preview without
affecting the image until you click on OK . Mode
The examples will be about the following image:
More white (larger value)
Pixels will be propagated from upper value pixels towards
lower value pixels. So bright areas will enlarge.
Figure 17. 73. More white
Bright pixels have been propagated to dark pixels in
the four directions : top, bottom, right and left.
Filter applied several times to increase effect.
More black (smaller value)
Pixels will be propagated from lower value pixels towards
upper value pixels. So dark areas will enlarge.
Figure 17. 74. More black Figure 17.75. To bottom only
The same as above with To bottom
direction only checked.
Middle value to peaks
On a border between the selected thresholds, the average of
both values is propagated.
Figure 17.76. Middle value to peaks
A thin border with a transitional color has been
added to objects. It is not visible around objects
with smoothed borders.
Green area zoomed x800. A thin border (one pixel wide )
has been added. Its value is the average between grey
(90%) and green (78%) : (90 + 78) / 2 = 84.
Foreground to peaks
The propagated areas will be filled with the foreground
color of the toolbox.
Figure 17.77. Foreground to peaks
In this example, the foreground color in Toolbox is
Red. A thin border, one pixel wide , red, is added
around objects. With smoothed objects, this border is
located at the furthest limit of smoothing. Here,
another border appears inside. This is an artifact due
to the small size of the object which makes the
smoothing area of opposite sides to overlap.
Only foreground
Only areas with the Toolbox Foreground color will propagate.
Figure 17.78. Only foreground
In this example, the foreground color in Toolbox is
that of the green object. After applying filter
several times, the green area is clearly enlarged.
Only background
Only areas with the Background color will propagate.
More opaque, More transparent
These commands work like “ More white ” and
“ More black ” . Opaque (transparent) areas will
be propagated over less opaque (transparent) areas. These
commands need an image with an alpha channel.
Figure 17.79. More opaque
Original layer, with a transparent background.
Filter applied several times: the green, opaque, area
got increased.
Propagate Lower threshold, Upper threshold
A pixel will be propagated (spread) if the difference in
value between the pixel and its neighbour is no smaller than
the lower threshold and no larger than the upper threshold.
Propagating rate
That's the propagating amount. The higher it will be the
more colored the propagation will be.
To left, To top, To right, To bottom
You can select one or more directions.
Propagating alpha channel
If checked, the pixel alpha value will be propagated,
otherwise the pixel will get the alpha of the neighbouring
pixels. This checkbox is only visible when the active layer
has an alpha channel .
Propagating value channel
If checked, the pixel 's color channels (gray channel on
grayscaled images) will be propagated. The option is
checked by default , of course. This checkbox too is only
visible when the active layer has an alpha channel .
4.14. Shift 4.16. Video
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12. 11. Warp 12.11. Warp 12. Map Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  12. 11. Warp 12.11. 1. Overview
This filter displaces pixels of active layer or selection according to
the grey levels of a Displacement map . Pixels are
displaced according to the gradient slope in the displacement map.
Pixels corresponding to solid areas are not displaced; the higher the
slope, the higher the displacement.
Figure 17.272.
From left to right: original image, displace map, displaced image
Solid areas of displacement map lead to no displacement. Abrupt
transitions give an important displacement. A linear gradient
gives a regular displacement. Displacement direction is
perpendicular to gradient direction (angle = 90°).
Figure 17.273. With a non-linear gradient A non-linear gradient leads to curls. Figure 17.274. With a complex gradient:
And a complex gradient, such as the
Solid Noise
filter can create, gives a swirl effect.
This filter offers the possibility of masking a part of the image to
protect it against filter action.
 12. 11. 2. Activating the filter
This filter is found in the image window menu under
Filters → Map → Warp .  This filter has no Preview.
12. 11.3. Options Figure 17. 275. Warp filter options Basic Options Step size “ Step ” is displacement distance for every filter
iteration. A 10 value is necessary to get a one pixel
displacement. This value can be negative to invert
displacement direction.
Iterations
The number of repetitions of effect when applying filter.
On edges
Because of displacement, a part of pixels are driven over the
borders of layer or selection, and, on the opposite side, pixels
places are emptying. Four following options allow you to fix this
issue:
Wrap
What goes out on one side is going into the opposite side
(this is the default).
Smear
Emptying places are filled with a spreading of the
neighbouring image line.
Black
Emptying places are filled with black color.
Foreground color
Emptying places are filled with the Foreground color of the
color area in Toolbox.
Displacement map
To be listed in this drop-down list, the displacement map, which
should be a grayscaled image, must be present on your
screen when you call filter and must have the same size as the
original image .
Advanced Options Dither size
Once all pixels displaced, this option scatters them randomly,
giving grain to the image. The higher this value (0.00-100.00),
the thinner the grain.
Figure 17.276. With a 3.00 dither size: Rotation angle
This option sets displacement angle of pixels according to the
slope direction of gradient. Previous examples have been created
with a vertical gradient and a 90° angle: so, pixels were
displaced horizontally and nothing went out of the image borders.
Here is an example with a 10° angle and 6 iterations:
Figure 17.277. With a 10° angle and 6 iterations:
Displacement is made according to a 10° angle against
vertical. Pixels going out the lower border on every
iteration are going into through the upper border (Wrap
option checked), giving a dotted line.
Substeps
If you specify a value & gt; 1, the displacement vector is computed in
several substeps, giving you a finer control to the displace
process.
Magnitude map
In addition to displacement map, you can add a Magnitude map. This
map should also be a grayscaled image , with the same size as the
source image and which must be present on your screen when you
call filter . This map gives more or less strength to filter on
some parts of the image , according to the grey levels of this
magnitude map. Image areas corresponding to white parts of this
map will undergo all the strength of filter. Image areas
corresponding to black parts of the map will be spared by filter.
Intermediate grey levels will lessen filter action on
corresponding areas of the image.
Use magnitude map must be checked
for that.
Figure 17.278. Magnitude Map example:
From left to right: original image, displacement map,
magnitude map, after applying “ Warp ”
filter. You can see that the black areas of magnitude map
prevent filter to take action.
More Advanced Options
These extra options let you add two new maps, a gradient map and/or
a vector map.
Note
To test these options alone, you must use a map with a solid color
for all the other maps.
Gradient scale
Using a gradient map, ( this map should also be a grayscaled
image ), the displacement of pixels depends on the direction of
grayscale transitions. The Gradient scale
option lets you set how much the grayscale variations will
influence the displacement of pixels. On every iteration, the
filter works of the whole image, not only on the red object: this
explains blurredness.
Figure 17.279. Gradient scale example
From left to right: original image, Gradient map, filter
applied.
In the example above, “ Warp ” filter is applied with a
gradient map (Gradient scale = 10.0). Gradient is oblique, from
top left to right bottom. The part of the image corresponding to
the gradient is moved obliquely, 90° rotated (Rotation angle 90°
in Advanced Options).
Vector mag
With this map, the displacement depends on the angle you set in
the Angle text box. 0° is upwards. Angles go
counter-clockwise. The vector control map
determines by how many pixels the image will move on every
iteration.
Figure 17.280. Vector mag example
From left to right: original image, displacement map,
filter applied.
In the above example, “ Warp ” filter is applied with a
Vector mag. Gradient is vertical, from top to bottom. Vector angle
is 45°. The image is moved obliquely, 45° to the top left corner.
The image is blurred because every iteration works on the whole
image, and not only on the red bar.
Angle Angle for fixed vector map (see above). 12.10. Tile 13. Rendering Filters
 Report an error in Bugzilla  4. 17. Waves 4.17. Waves 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 17. Waves 4. 17. 1. Overview Figure 17. 82. Example for the Waves filter Original image Filter “ Waves ” applied
With this filter you get the same effect as a stone thrown in a quiet
pond, giving concentric waves.
 4. 17. 2. Activating the filter
You can find this filter through
Filters → Distorts → Waves .  4. 17.3. Options Figure 17. 83. “ Waves ” filter options Preview
All your setting changes will appear in the Preview without
affecting the image until you click on OK . Don't keep Preview checked if your computer
is too slow.
Mode Smear
Because of the waves, areas are rendered empty on sides. The
adjacent pixels will spread to fill them.
Blacken
The empty areas will be filled by black color.
Reflective
Waves bounce on sides and interfere with the arriving ones.
Amplitude Varies the height of waves. Phase This command shifts the top of waves. Wavelength Varies the distance between the top of waves. 4.16. Video 4.18. Whirl and Pinch  Report an error in Bugzilla  4. 18. Whirl and Pinch 4.18. Whirl and Pinch 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 18. Whirl and Pinch 4. 18. 1. Overview Figure 17. 84. Example for the Whirl and Pinch filter Original image Filter applied “ Whirl and Pinch ” distorts your image in a concentric way.
“ Whirl ” (applying a non-zero
Whirl angle ) distorts the image much like the
little whirlpool that appears when you empty your bath.
“ Pinch ” , with a nil rotation, can be compared to
applying your image to a soft
rubber surface and squeezing the edges or corners. If the Pinch amount
slider is set to a negative value, it will look as if someone
tried to push a round object up toward you from behind the
rubber skin. If the Pinch amount is set to a positive value , it
looks like someone is dragging or sucking on the surface from
behind, and away from you.
Tip
The “ pinch ” effect can sometimes be used to compensate
for image distortion produced by telephoto or fish-eye lenses
( “ barrel distortion ” ).
Figure 17.85. Illustration Original Whirled Pinched  4. 18. 2. Activating the filter
You can find this filter through
Filters → Distorts → Whirl and Pinch  4. 18. 3. Parameter Settings Figure 17. 86. “ Whirl and Pinch ” filter options Preview
Changes to parameters are immediately displayed into the
Preview . The whirlpool is focused around the
center of the current layer or selection .
Whirl angle
Clockwise or counter clockwise (-360 to +360). Controls how many
degrees the affected part of the image is rotated.
Pinch amount
Whirlpool depth(-1 to +1). Determines how strongly the affected
part of the image is pinched.
Radius
Whirlpool width (0.0-2.0). Determines how much of the image is
affected by the distortion. If you set
Radius to 2, the entire image will be
affected. If you set Radius to 1, half the
image will be affected. If Radius is set to
0, nothing will be affected (think of it as the radius in a circle
with 0 in the center and 1 halfway out).
4.17. Waves 4.19. Wind
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4. 19. Wind 4.19. Wind 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 19. Wind 4. 19. 1. Overview Figure 17. 87. “ Wind ” filter example Original image Filter “ Wind ” applied
The Wind filter can be used to create motion blur, but it can
also be used as a general distort filter. What is characteristic
about this filter is that it will render thin black or white
lines. Wind will detect the edges in the image, and stretch out
thin white or black lines from that edge. This is why you can
create the illusion of motion, because the edges are what will
be blurred in a photograph of a moving object.
 4. 19. 2. Activating the filter
You can find this filter through
Filters → Distorts → Wind .  4. 19.3. Options Figure 17. 88. “ Wind ” filter options
The interface is quite simple. You can set the
Strength of the wind and a
Threshold value. Threshold
will restrict the effect to fewer areas of the image.
Strength controls the amount of wind, so a high
value will render a storm. You can also increase the effect by setting
the Style to Blast, which will produce thicker
lines than Wind.
You can only set the wind in two directions, either Left or Right.
However, you can control which edge the wind will come from using the
values Leading, Trailing or Both. Because Trailing will produce a black
wind, it creates a less convincing motion blur than Leading, which will
produce white wind.
The following illustrations are based on this image:
Preview
All your setting changes will appear in the Preview without
affecting the image until you click on OK .
It reproduces a part of the image only, centred on the first
modified area it encounters.
Style Wind
This option is the most suggestive of a moving effect.
Trails are thin.
Blast
This option tries to suggest a blast due to an explosion.
Trails are thick.
Direction
You can select the direction, Left or
Right , from which the wind comes.
Edge Affected Leading
Trails will start from the front border, falling on the
object itself. It suggests that a violent wind is pulling
color out.
Trailing
Trails start from the back border of the object.
Both Combines both effects. Threshold
The threshold to detect borders. The higher it is, the fewer
borders will be detected.
Strength
Higher values increase the strength of the effect. 4.18. Whirl and Pinch 5. Light and Shadow Filters  Report an error in Bugzilla  6. 18. Zealous Crop 6.18. Zealous Crop 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 18. Zealous Crop
The Zealous Crop command crops an image
using a single solid color as a guide. It crops the edges, as with
the Autocrop command, but it
also crops the areas in the middle of the image which have the
same color (at least, in principle).
Caution
Please note that Zealous Crop crops all of
the layers, although it only analyzes the active layer. This may
lead to a loss of information from the other layers.
6.18.1. Example Figure 16.70. “ Zealous Crop ” Example Original image “ Autocrop ” applied
“ Zealous Crop ” applied
 6. 18. 2. Activate the Command
You can access this command from the image menu bar through
Image → Zealous Crop .  6. 17. Autocrop Image 6. 19. Merge Visible Layers
 Report an error in Bugzilla  13. 3. Fog 13.3. Fog 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 3. Fog 13. 3. 1. Overview Figure 17. 282. Example for the “ Fog ” filter Original image “ Fog ” applied
This filter adds a new layer with some clouds to the image that look
like fog or smoke. The clouds are created with the
Plasma texture.
 13. 3. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Clouds → Fog .  13. 3.3. Options Figure 17. 283. “ Fog ” options
Among the few filter options, only “ Turbulence ” is
somewhat important, because you can't change it later and have to undo
and repeat the filter if the result doesn't fit your desire.
Layer name
The name of the layer . You can change it later in the
Layers Dialog .
Fog color
Defaults to some kind of sandy brown (240, 180, 70). Click on the
color button to change this if you think that is not the natural
color of fog.
Turbulence
This is actually the Turbulence option of the
Plasma filter: it controls
the complexity of the clouds, from soft (low values) to hard (high
values).
Opacity
The opacity of the layer . You can change it later in the Layers Dialog .
13.2. Difference Clouds 13. 4. Plasma
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14. 4. Slice 14.4. Slice 14. Web Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  14. 4. Slice 14. 4. 1. Overview Figure 17. 352. Example for the “ Slice ” filter Original image with guides “ Slice ” applied
This filter is a simple and easy to use helper for creating sensitive
images to be used in HTML files. The filter slices up the source image
(like the Guillotine command
does) along its horizontal and vertical guides, and produces a set of
sub-images. At the same time it creates a piece of HTML code for a table
saved in a text file. Every table cell contains one part of the image.
The text file should then be embedded in an HTML document.
Note that this filter is really a very simple helper. A typical HTML
code produced by the filter may be not much more than this:
Example 17.1. Simple “ Slice ” filter example output
& lt;table cellpadding="0" border="0" cellspacing="0" & gt;
& lt;tr & gt;
& lt;td & gt; & lt;img alt="" src=" slice_0_0. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" slice_0_1. png"/ & gt; & lt;/ td & gt;
& lt; /tr & gt;
& lt;tr & gt;
& lt;td & gt; & lt;img alt="" src=" slice_1_0. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" slice_1_1. png"/ & gt; & lt;/ td & gt;
& lt; /tr & gt;
& lt;/table & gt;
Produced HTML code; the “ style ” attribute has been
omitted.
When there are no guides in the image, the filter will no nothing. If,
however, the guides are just hidden, the filter will work.
Tip
The ImageMap filter is a much
more powerful and sophisticated tool for creating sensitive images.
(But it is also much more complex...)
 14. 4. 2. Activate the filter
This filter is found in the image window menu under
Filters → Web → Slice .  14. 4.3. Options Figure 17. 353. “ Slice ” options
Most options are self-explanatory, but nevertheless:
Path for HTML export
Where the HTML file and the image files will be saved. By default
these files will be stored in the current working directory.
Clicking on the button to the right opens a pull-down menu, where
you can select a different location.
Filename for export
The name of the HTML file. You can change the filename using the
textbox.
Image name prefix
The name of an image file produced by this filter is
prefix_i_k.ext , where
prefix is that part of the filename which you
can freely select using the textbox to the right, by default:
slice .
( i and k are the numbers
of the row and the column, each starting with 0;
.ext is the filename
extension depending on the selected
Image format .)
This option is particularly useful when you want to create
Javascript for onmouseover and clicked and
need different sets of images.
Image format
You can choose to create image files in the
GIF ,
JPG , or
PNG
file format .
Separate image folder, Folder for image export
When Separate image folder is enabled, a
folder will be created where the image files will be placed. By
default, the name of this destination folder is
images , but you can change
it in the Folder for image export textbox.
Example 17.2. With separate image folder
Result of enabled “ Separate image folder ”
Space between table elements
This value (0-15) will be passed as “ cellspacing ”
attribute to the HTML table. The result is, that horizontal and
vertical guides will be replaced with stripes of the specified
width:
Example 17.3. Space between table elements Corresponding HTML code snippet
Note that the image will not be enlarged by the size of these
stripes. Instead, the resulting HTML image will look like you have
drawn the stripes with the Eraser tool.
Javascript for onmouseover and clicked When this option is enabled , the filter will also add some
JavaScript code. Like the HTML code, this code does not work as
is, rather it's a good starting point for adding some dynamic
functionality. The JavaScript code provides a function to handle
events like “ onmouseover ” :
Example 17.4. JavaScript code snippet
function exchange (image, images_array_name, event)
{
name = image.name;
images = eval (images_array_name);
switch (event)
{
case 0:
image.src = images[name + " _plain"].src;
break;
case 1:
image.src = images[name + " _hover"].src;
break;
case 2:
image.src = images[name + " _clicked"].src;
break;
case 3:
image.src = images[name + " _hover"].src;
break;
}
}
Skip animation for table caps
When disabled, the filter will add a & lt;a href="#" & gt; ... & lt;/a & gt;
hyperlink stub to every table cell. When enabled (this is the
default) and there are at least two horizontal or two vertical
guides, the filter will not add a hyperlink stub to the first and
last cell in a column or row. This may be useful when you have an
image with border and you don't want to make the border sensitive.
Example 17.5.
Skipped animation for table caps (simplified HTML code)
& lt;table cellpadding="0" border="0" cellspacing="0" & gt;
& lt;tr & gt;
& lt;td & gt; & lt;img alt="" src=" images/slice_0_0. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" images/slice_0_1. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" images/slice_0_2. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" images/slice_0_3. png"/ & gt; & lt;/ td & gt;
& lt; /tr & gt;
& lt;tr & gt;
& lt;td & gt; & lt;img alt="" src=" images/slice_1_0. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; a href="#" & gt; & lt;img alt="" src="images/ slice_1_1. png"/ & gt; & lt;/ a & gt; & lt;/td & gt;
& lt;td & gt; & lt; a href="#" & gt; & lt;img alt="" src="images/ slice_1_2. png"/ & gt; & lt;/ a & gt; & lt;/td & gt;
& lt;td & gt; & lt; img alt="" src="images/slice_1_3. png"/ & gt; & lt;/ td & gt;
& lt; /tr & gt;
& lt;tr & gt;
& lt;td & gt; & lt;img alt="" src=" images/slice_2_0. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" images/slice_2_1. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" images/slice_2_2. png"/ & gt; & lt;/ td & gt;
& lt; td & gt; & lt; img alt="" src=" images/slice_2_3. png"/ & gt; & lt;/ td & gt;
& lt; /tr & gt;
& lt;/table & gt;
Only inner cells have (empty) hyperlinks.
14.3. Semi-Flatten 15. Animation Filters
 Report an error in Bugzilla  16. 2. 3D Outline 16. 2. 3D Outline 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 2. 3D Outline 16. 2. 1. Overview Figure 17. 370. Example for the “ 3D Outline ” filter The “ 3D Outline ” filter The “ 3D Outline ” logo
This filter is derived from the “ 3D Outline ” script
( File → Create → Logos → 3D Outline in the image window),
which creates a logo (see above) with outlined text and a drop shadow.
The filter outlines the non- transparent areas of the active layer
(determined from the Alpha channel) with a pattern and adds a drop
shadow.
Here, we will use the alpha term to refer to these
areas of the active layer defined by the non-transparent pixels.
The filter uses the Sobel edge
detect filter to get the alpha's outline. So with a simple alpha,
for example a cleared rectangle selection, you will just get the
boundary. But when you use a layer mask (don't forget to Apply the
Layer Mask), as in the following example, the edge detector will find
more edges and thus the filter effect will be applied to these edges
too.
Figure 17.371. Example based on multicolored layer mask With an layer mask (alpha) like this ... ... you will get this. Warning
The image will always be resized to the active layer's size.
 16. 2. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → 3D Outline .  The filter only works if the active layer has an alpha channel .
Otherwise, the menu entry is insensitive and grayed out.
16. 2.3. Options Figure 17. 372. “ 3D Outline ” options Pattern
Here you can see and change the currently selected pattern. When
you click on the pattern, an enlarged preview will popup.
Pressing the Browse... button opens a
dialog where you can select a different pattern.
Outline blur radius
This radius is used to blur
the alpha before the edge
detector will select the area to be filled with the
pattern. That's why a high value results in a wide but smeared
pattern:
Figure 17.373. Outline blur radius example Radius: 5 Radius: 20 Radius: 40 Shadow blur radius
This radius is used to blur
the drop shadow. A high value will smear the shadow:
Figure 17.374. Shadow blur radius example Radius: 10 Radius: 20 Radius: 40 Bumpmap (alpha layer) blur radius
The Bump Map used to
create a 3D effect is the active layer (alpha layer) with the
edge detect filter applied.
Before it is used to emboss the pattern layer, another
Gaussian blur will be applied
with the specified radius. So a high value will reduce the 3D
effect.
Default bumpmap settings
If checked ( this is the default) the bump map plug-in will be
applied with its default options. Otherwise, the
Bump Map dialog window
will popup while the filter is running, and you can choose
different options. Note that, when you close the window pressing
the Cancel button, no bump map at all will be
applied.
Shadow X offset; Shadow Y offset
This is the amount of pixels the shadow layer will me moved to the
right (X) and down (Y). Then the layer will be clipped to the
image size. Note that there is no real background layer, and
moving the shadow will clear its original place:
Figure 17.375. Shadow offset example X offset: 50; Y offset: 20 16. Alpha to Logo Filters 16. 3. Alien Glow
 Report an error in Bugzilla  11. 2. Add Bevel 11. 2. Add Bevel 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 2. Add Bevel 11. 2. 1. Overview Figure 17. 216. Example for the “ Add Bevel ” filter
Original image, the colored rectangle is selected
“ Add Bevel ” applied
This filter adds a slight bevel to an image using a
bump map (see below). If there is a
selection , it is bevelled, otherwise the filter has no effect.
Figure 17.217. Another “ Add Bevel ” example, with bumpmap Original image Bumpmap Filter applied  11. 2. 2. Activate the filter
You can find this filter in the image window menu under
Filters → Decor → Add Bevel .  11. 2.3. Options Figure 17. 218. “ Add Bevel ” options Thickness
You can specify the thickness of the bevel, in pixels. Maximal
thickness is 30 pixels.
Work on copy
If checked, the filter creates a new window containing a copy of
the image with the filter applied. The original image remains
unchanged.
Keep bump layer
When checked, you will keep the generated bumpmap as a new, not
visible layer (below the layer dialog):
11. Decor Filters 11.3. Add Border
 Report an error in Bugzilla  11. 3. Add Border 11.3. Add Border 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 3. Add Border 11. 3. 1. Overview Figure 17. 219. Example for the “ Add Border ” filter Original image Border added
This filter just does what its name says: it adds a border to the image.
You can specify the thickness of the border as well as the color. The
four sides of the border are colored in different shades, so the image
area will appear raised.
The image will be enlarged by the border size, it won't be painted over.
 11. 3. 2. Activate the filter
This filter is found in the image window menu under
Filters → Decor → Add Border .  11. 3.3. Options Figure 17. 220. “ Add Border ” options Border X size, Border Y size
Here you can select the thickness of the added border, in pixels.
X size (left an right) and Y size (top and bottom) may be
different. Maximum is 250 pixels.
Border color
Clicking on this button brings up the color selector dialog that
allows you to choose an “ average ” border color (see
below, Delta value on color ).
Delta value on color
This option makes the border sides to be colored in different
shades and thus makes the image to appear raised. The actual
color of the respective border side is computed for every color
component red, green, and
blue [15]
from the “ average ” Border color
as follows (resulting values less than 0 are set to 0, values
greater than 255 are set to 255):
Top shade = Border color + Delta Right shade = Border color - ½ Delta Bottom shade = Border color - Delta Left shade = Border color + ½ Delta Figure 17.221. Delta examples “ Add Border ” filter applied with
Delta value 25, then with 75, 125, 175,
and 225.
Example: the default color is blue (38,31,207), default delta is
25. So the shades of the borders are: top: (38,31,207) +
(25,25,25) = (63,56,232), right: (38,31,207) + (-13,-13,-13) =
(25,18,194), etc.
[15]
See image types
or RGB .
11.2. Add Bevel 11. 4. Coffee Stain
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16. 3. Alien Glow 16.3. Alien Glow 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 3. Alien Glow 16. 3. 1. Overview Figure 17. 376. Example for the “ Alien Glow ” filter The “ Alien Glow ” filter The “ Alien Glow ” logo
This filter adds an eerie glow around the active layer's alpha .
The filter is derived from the “ Alien Glow ” script
( File → Create → Logos → Alien Glow in the image window),
which creates a logo with the above text effect.
Warning
The image will always be resized to the active layer's size.
 16. 3. 2. Activate the filter
You can find this filter in the image window menu under
Filters → Alpha to Logo → Alien Glow .  16. 3.3. Options Figure 17. 377. “ Alien Glow ” options Glow size (pixels * 4)
This is actually the font size option of the
“ Alien Glow ” Script-Fu script. However, two values
will be set in relation to this size : the glow will be enlarged by
“ Glow size ” / 30, and feather radius is
“ Glow size ” / 4. You should probably choose the
height of your objects for this option (ignore
“ pixels * 4 ” ).
Glow color
This is the color of the “ eerie ” glowing. Of course
it defaults to green (63,252,0), but a click on the swatch
button brings up the color selector where you can choose any
color.
16.3.4. Filter details
Reproducing an eerie alien glow is easy:
If necessary, create a
selection from
the alpha channel of the active layer .
Fill the selection with the following
Gradient Blend : Shape =
Shaped (spherical); Gradient = FG to BG (RGB), with FG = dark gray
(79,79,79), BG = black.
Create a new layer
( “ Alien Glow ” ) below.
Extend the selection
slightly,
feather it,
and fill it with the Glow color .
Create a new background layer filled with black.
16.2. 3D Outline 16. 4. Alien Neon
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16. 4. Alien Neon 16. 4. Alien Neon 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 4. Alien Neon 16. 4. 1. Overview Figure 17. 378. Example for the “ Alien Neon ” filter “ Alien Neon ” applied Caution
Sorry, there is no documentation for this filter as yet.
 16. 4. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Alien Neon .  16. 4.3. Options Figure 17. 379. “ Alien Neon ” options Glow color
TODO
Background color
TODO
Width of bands
TODO
Width of gaps
TODO
Number of bands
TODO
Fade away
TODO
16.3. Alien Glow 16.5. Basic I & II  Report an error in Bugzilla  16. 5. Basic I & II 16.5. Basic I & II 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 5. Basic I & II 16. 5. 1. Overview Figure 17. 380. Examples for the “ Basic ” filters Basic I Basic II
These filters add a gradient effect to the alpha channel of active layer as well as a
drop shadow and a background layer .
The “ Basic II ” also adds a highlight layer.
 Warning
The image will always be resized to the active layer's size.
The filters are derived from the “ Basic I ” and
“ Basic II ” logo scripts
(see File → Create → Logos ),
which draw a text with the filter effect, e.g.
The “ Basic I ” logo script.   16. 5. 2. Activate the filter
You can find the filter in the image window menu under
Filters → Alpha to Logo → Basic I
and
Filters → Alpha to Logo → Basic II .  16.5.3. Options Figure 17. 381. “ Basic ” filter options “ Basic I ” options “ Basic II ” options Background color
This color is used to fill the background layer created by the
filter. It defaults to white.  When you click on the color swatch
button , a color selector pops up where you can select any other
color.  Text color
The name of this option refers to the text color of the logo
scripts that were mentioned above. Here this color — by
default blue (6,6,206) for “ Basic I ” and red
(206,6,50) for “ Basic II ” — sets the basic
color of the gradient effect: this is the color the alpha channel
will be filled with before the gradient effect will be applied.
16.5.4. Filter details
You can reproduce the gradient effect manually by using the
Blend tool with the following
options:
Mode : Multiply, Gradient : FG to BG (RGB), where FG is white and
BG is black,
Offset : 20, Shape : Radial, Dithering : checked. 16.4. Alien Neon 16. 6. Blended
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15. 2. Blend 15.2. Blend 15. Animation Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. 2. Blend 15. 2. 1. Overview Figure 17. 355.
Example for the “ Blend ” filter: original image
4 frames of 5 frames (white background layer omitted) Figure 17.356.
Example for the “ Blend ” filter: filter applied
First 8 (of 16) frames
 15. 2. 2. Activating the filter
This filter is found in the image window menu under
Filters → Animation → Blend .  15. 2.3. Options
Figure 17. 357. “ Blend ” options Intermediate frames
TODO
Max. blur radius
TODO
Looped
TODO
15. Animation Filters 15.3. Burn-In
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16. 6. Blended 16.6. Blended 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 6. Blended 16. 6. 1. Overview Figure 17. 382. Example for the “ Blended ” filter “ Blended ” applied Caution
Sorry, there is no documentation for this filter as yet.
 16.6. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Blended .  16. 6.3. Options Figure 17. 383. “ Blended ” options Offset (pixels)
TODO
Backgroundcolor
TODO
Blend mode
TODO
Start blend
TODO
End blend
TODO
Gradient
TODO
Gradient reverse
TODO
16.5. Basic I & II 16. 7. Bovination
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16. 7. Bovination 16.7. Bovination 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 7. Bovination 16. 7. 1. Overview Figure 17. 384. Example for the “ Bovination ” filter “ Bovination ” applied
This filter adds “ cow spots ” to the active layer alpha
channel.
Warning
The image will always be resized to the active layer's size.
 16. 7. 2. Activate the filter
You can find this filter in the image window menu under
Filters → Alpha to Logo → Bovination .  16. 7.3. Options Figure 17. 385. “ Bovination ” options Spots density X, Spots density Y
The horizontal (X) and vertical (Y) spots density will be used by
the Solid Noise filter
as X Size and Y Size
options. So these values range from 1 to 16, with high values
resulting in many spots in the respective dimension, low values
resulting in few spots.
Figure 17.386. “ Spots density ” examples Maximum X density, minimum Y density Maximum Y density, minimum X density Background Color
This is the color used to fill the “ Background ”
layer; it defaults to white. When you click on the color button ,
you may choose any other color in the color selector dialog.
16.7. 4. Filter details
The filter fills the alpha channel with
Solid Noise :
... and maximizes the
Contrast :
Besides, the filter adds a
Blur
layer as a light gray shadow and uses this layer as a
Bump Map . Finally a (by default)
white “ Background ” layer is added below.
So the filter will end up with these layers: [19]
[19]
If the active layer is not the top layer, it might happen that the
filter messes up the layers. Then you will have to
raise the active layer .
16.6. Blended 16.8. Chalk
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15. 3. Burn-In 15.3. Burn-In 15. Animation Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. 3. Burn-In 15. 3. 1. Overview Figure 17. 358.
Example for the “ Burn-In ” filter: original image
Opaque background layer and foreground layer with transparency
Figure 17.359.
Example for the “ Burn-In ” filter: filter applied
Resulting image with 8 frames (depending on size and speed)
 15. 3. 2. Activating the filter
This filter is found in the image window menu under
Filters → Animation → Burn-In .  15. 3.3. Options
Figure 17. 360. “ Burn-In ” options Glow color
TODO
Fadeout
TODO
Fadeout width
TODO
Corona width
TODO
After glow
TODO
Add glowing
TODO
Prepare for GIF
TODO
Speed (pixels/frame)
TODO
15.2. Blend 15.4. Rippling
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11. 9. Stencil Carve 11.9. Stencil Carve 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 9. Stencil Carve 11. 9. 1. Overview Figure 17. 240. Example for the “ Stencil Carve ” filter Original image “ Stencil Carve ” applied
This filter works with two images, source and target. The source image
must be a grayscale image containing a single layer and no Alpha
channel. This layer is used as selection mask and will work as stencil
for the carving effect. The image to be carved (the target image) can
be an RGB color or grayscale image, also with a single layer. This
target image must have the same size as the source image.
 11. 9. 2. Activating the filter
This filter is found in the image window menu under
Filters → Decor → Stencil Carve .  Tip
If this command remains grayed out although the image is grayscale,
check for an Alpha channel and delete it.
11. 9.3. Options Figure 17. 241. “ Stencil Carve ” options Image to carve
Here you may select the target image, i.e. the image the carving
effect is applied to. The drop-down list will show you a list of
opened images which may be carved.
Carve white areas
If checked ( default), the source image is used as stencil as
described above. If unchecked, the inverted
source image is used as stencil , e.g.:
Figure 17.242. Engraving Masks Normal mask Inverted mask
In the example below, the source is a grayscale image. The target
is an image with a wood pattern.
On the left, Carve white areas is enabled.
The pixels of the target image corresponding to white pixels in
the stencil (around the text) have been carved. The result is an
embossed text.
On the right, Carve white areas is disabled.
The pixels of the target image corresponding to the black pixels
in the stencil ( the text) have been carved. The result is a hollow
text.
Figure 17.243. Example for “ Carve white areas ” White areas carved Stencil Black areas carved
Information about the many layers created by this filter can be
found in [ GROKKING ] .
11.8. Slide 11.10. Stencil Chrome
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16. 8. Chalk 16.8. Chalk 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 8. Chalk 16. 8. 1. Overview Figure 17. 387. Example for the “ Chalk ” filter Original image “ Chalk ” applied
This filter creates a chalk drawing effect for the active layer.
It is derived from the “ Chalk ” script
( File → Create → Logos → Chalk in the image window),
which creates a logo from a text of your choice, for instance:
The “ Chalk ” logo Warning
The image will always be resized to the active layer's size.
 16.8. 2. Activate the filter
You can find this filter in the image window menu under
Filters → Alpha to Logo → Chalk .  16. 8.3. Options Figure 17. 388. “ Chalk ” option Background color
The background color is the color of the
“ blackboard ” you are drawing on with chalk, and of
course it's black.  When you click on the color button , the color
selector pops up and you may select any other color.  16.8.4. Filter details The “ Chalk ” filter applies a Gaussian blur to the
layer , spreads the pixels, and
ripples the layer
horizontally and vertically,
extracts edges using the Sobel
edge detect filter , and
Note
Sometimes the sobel edge detect produces some garbage at the
image sides.
increases the luminosity level .
Unfortunately you cannot change the tool and filter options. But you may
reproduce the process step by step using the methods listed above,
varying the respective options. Then you just have to add a background
layer filled with any color. That's all.
16.7. Bovination 16.9. Chip Away
 Report an error in Bugzilla  16. 9. Chip Away 16. 9. Chip Away 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 9. Chip Away 16. 9. 1. Overview Figure 17. 389. Example for the “ Chip Away ” filter The “ Chip Away ” filter The “ Chip Away ” logo
This filter adds a chipped woodcarving effect to the alpha channel of
the active layer . Optionally it adds a drop shadow to the image.
The content of the active layer doesn't matter, only the shape of its
alpha channel does.
 Warning
The image will always be resized to the active layer's size.
The filter is derived from the “ Chip Away ” Script-Fu script
( File → Create → Logos → Chip Away ),
which creates a text logo with the effect shown above.   16. 9. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Chip Away .  16. 9.3. Options Figure 17. 390. “ Chip Away ” options Chip amount
This option lets you vary the size of chipping area. But note that
“ Chip amount ” is not the size of this area in pixels.
It is used as the maximum amount pixels are randomly spread by the
Spread filter applied to the
bump map. Valid range is 0-200.
Figure 17.391. “ Chip amount ” examples 0 30 60 90 Blur amount
The specified value will be passed as “ Radius ” option
to the Gaussian blur filter,
which will blur the bump layer by this amount.
Invert
If checked, the bump map
will be inverted and will create hollows instead of bumps, which
makes the image looking carved.
Figure 17.392. “ Chip Away ” inverted example Inverted, (without drop shadow) Drop shadow
If checked, a Drop
shadow will be added to the image in a new layer below the
active layer .
Keep bump layer
By default, the bump map
used to create the chipping effect will be removed after applying
the filter. When this option is checked , the bump map will be kept
as an invisible layer.
Fill BG with pattern
If checked, the background layer (added by the filter) will be
filled with the specified Pattern . Otherwise,
it will be filled with white.
Keep background
Whether or not to remove the background layer . This option is
checked by default . You can, of course, remove this layer (or
toggle its visibility) later in the
Layers dialog .
Pattern
This option consists of a preview area, which will produce a popup
preview when you click on it and hold down the mouse button, and a
Browse button. The button will popup a
dialog where you can select patterns.
The default pattern is “ Burlwood ” . Apart from that
one, the plug-in author suggests the patterns
“ Dried mud ” , “ 3D Green ” , and
“ Slate ” :
Figure 17.393. Suggested “ Chip Away ” patterns Dried mud 3D Green Slate 16.9.4. Filter details To achieve a chipping effect, the filter...
...creates a
selection from the
alpha channel in a new layer,
fills the selection with white, spreads the pixels,
and applies a Gaussian blur to
the layer .
Then it uses this layer as a Bump
map , creating a 3D effect.
16.8. Chalk 16.10. Chrome
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16. 10. Chrome 16.10. Chrome 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 10. Chrome 16. 10. 1. Overview Figure 17. 394. Example for the “ Chrome ” filter The “ Chrome ” filter applied The “ Chrome ” logo
This filter is derived from the “ Chrome ” logo script
( File → Create → Logos → Chrome ),
which — according to the script author — creates a
“ simplistic, but cool, chromed logo ” (see above).
The filter adds this simple chrome effect to the alpha, that is the area
of the active layer defined by the non-transparent pixels (think of it
as a “ selection by visibility ” ). The filter effect will
always be applied according to the alpha values.
Apparently the effect only looks “ cool ” when the filter is
applied to thin areas. For wide shapes you can try to increase the
Offset value; see the examples
below .
Warning
The image will always be resized to the active layer's size.
 16. 10. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Chrome .  16. 10.3. Options Figure 17. 395. “ Chrome ” options Offset (pixels * 2)
This option is used when creating the chrome effect and for
placing the drop shadow:
Figure 17.396. “ Offset ” examples Offset 25 Offset 50 Offset 75
The filter creates a drop shadow in the shape of the alpha. This
shadow will be moved according to the specified offset in relation
to the alpha: by 40% of the offset to the right and by 30% offset
down. It will be
feathered by 50%
of the offset value.
The chrome effect will be achieved using some temporary layers.
These layers are moved by the same amount (40% and 30% of the
specified offset) and are also feathered by 50% offset. So the
appearance of the alpha too is determined by the offset value.
Background Color
This color is used to fill the background layer created by the
filter. It defaults to light gray.  When you click on the color
button , a color selector pops up where you can select any other
color.  16. 9. Chip Away 16. 11. Comic Book
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13. 16. Circuit 13.16. Circuit 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 16. Circuit 13. 16. 1. Overview Figure 17. 322. Example of Circuit Filter “ Circuit ” applied. Circuit command is a script that fills the
selected region (or alpha) with traces like those on the back of an old
circuit board. It looks even better when gradmapped with a suitable
gradient.
Tip
The effect seems to work best on odd shaped selections because of
some limitations in the maze codes selection handling ability.
If the image is in indexed colors, this menu entry is grayed out
and unavailable.
Note
This filter creates a grey level image in RGB mode.
The resulting image doesn't depend on the original image.
 13. 16. 2. Activate the filter
This filter is found in the image window menu under
Filters → Render → Circuit... .  13. 16.3. Options Figure 17. 323. “ Circuit ” filter options
Oilify mask size
With this option you can set the option value of the
Oilify filter in pixels
(range 3 to 50). Larger values make lines more fuzzy.
17 is the default value.
Circuit seed
You can give a randomizing seed number between 1 and 3000000.
The default value is 3.
No background (only for separate layer)
If this option is enabled , dark pixels of the circuit are made
transparent so that the underlying image is shown through
these holes. This option is disabled in default settings.
The Separate layer option is required.
Keep selection
If an active selection exists when this script is called,
you can keep the selection and its marching ants with this option.
This option is enabled in default settings.
Separate layer
If this option is not checked, the generated texture is drawn
on the active layer. When this option is enabled (in default ),
this script adds a layer to draw the circuit texture is on.
13.16.4. Making the Circuit effect The Circuit effect is achieved through the following steps:
First, draw maze with 5 pixels
width pathways and walls with the “ Depth First ”
algorithm. The pattern of maze is set by Circuit
seed .
Oilify this maze with a
brush of Oilify mask size .
Then apply the extract edge
filter with Sobel algorithm, Smear option and Amount to 2.0, to
the oilified maze image. This crowds high contrast winding curves
like as a circuit map.
Finally, Desaturate
the map with gray color in RGB mode.
13.15. Sinus 13.17. Fractal Explorer
 Report an error in Bugzilla  10. 4. Clothify 10.4. Clothify 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 4. Clothify 10. 4. 1. Overview Figure 17. 172. Example of Clothify Filter “ Clothify ” applied (in selection) Clothify command is a script which
adds a cloth-like texture to the selected region or alpha .
If the image is in indexed colors, this menu entry is grayed out
and unavailable.
This effect is achieved through the following steps:
Create an image in the same size as the original image , or selection
or region in alpha if it is given, then add a layer to this image
filled with white and
noisified strongly.
Reproduce a layer from the recently added layer and set the mode of
the upper layer to
Multiply .
Apply Gaussian blur in
different directions, horizontally on the lower layer by the given
parameter Blur X as the radius, and vertically
on the upper layer with Blur Y .
Merge these two layers into an image and make its contrast
expanded as possibly , then
slightly noisify again on this working image.
Finally do bump map on the
original image by the working image with parameters
Azimuth , Elevation , and
Depth .
 10. 4. 2. Activate the filter
This filter is found in the image window menu under
Filters → Artistic → Clothify... .  10. 4.3. Options Figure 17. 173. “ Clothify ” filter options Azimuth , Elevation , and
Depth come from
Bump Map filter.
Blur X, Blur Y
These parameters lengthen fibers of the texture, horizontally
by Blur X , and vertically by
Blur Y . The range of value is between
3 to 100.
Azimuth Azimuth slider controls the bearings
where light comes from according to the point of the compass.
Both the minimum value (0.00) and the maximum value (360.00)
are the direction of three o'clock on the dial panel of an
analogue clock. Increasing value goes counter-clockwise.
Elevation Elevation slider controls the height
where light comes from. For the minimal value (0.50)
the light comes from horizon, and for the maximum value
(90.0) the light comes from zenith.
Depth Depth slider controls distance between bump
height and hollow depth. Increasing value causes more rugged
features. Values vary from 1 to 65.
10.3. Cartoon 10.5. Cubism
 Report an error in Bugzilla  11. 4. Coffee Stain 11. 4. Coffee Stain 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 4. Coffee Stain 11. 4. 1. Overview Figure 17. 222. Example for the “ Coffee Stain ” filter Original image “ Coffee Stain ” applied
This filter adds realistic looking coffee stains to the image.
Every stain is created in a layer of its own . The stain layers are
randomly moved to let the stains spread out (at the end you may see the
boundary of the moved top layer). So after applying the filter you can
easily edit (e.g., move, scale, remove) the coffee stains, or create
additional stains using the filter again.
 11. 4.2. Activate the filter
The filter is found in the image window menu under
Filters → Decor → Coffee Stain .  11. 4.3. Options Figure 17. 223. “ Coffee Stain ” options Stains The number of the coffee stains (1-10). Darken only
Since every stain is created in a layer of its own , all layers
have to be merged to make the appearance of the image . If
this option is checked , the relevant
layer mode is set to
“ Darken only ” , otherwise it is set to
“ Normal ” .
The layer mode determines how the pixels of the layers are
combined. In “ Normal ” mode, every coffee stain covers
the pixels of the layers below . As a rule of thumb, if layer mode
“ Darken only ” is set, coffee stains covers
the corresponding pixels of the layers below them only if these
pixels are lighter.
11.3. Add Border 11.5. Fuzzy Border  Report an error in Bugzilla 
16. 11. Comic Book 16. 11. Comic Book 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 11. Comic Book 16.11. 1. Overview Figure 17. 397. Example for the “ Comic Book ” filter “ Comic Book ” applied Caution
Sorry, there is no documentation for this filter as yet.
 16. 11. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Comic Book .  16. 11.3. Options Figure 17. 398. “ Comic Book ” options Gradient
TODO
Gradient reverse
TODO
Outline size
TODO
Outline color
TODO
Background color
TODO
16. 10. Chrome 16.12. Cool Metal
 Report an error in Bugzilla  16. 12. Cool Metal 16. 12. Cool Metal 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 12. Cool Metal 16. 12. 1. Overview Figure 17. 399. Example for the “ Cool Metal ” filter The “ Cool Metal ” filter The “ Cool Metal ” logo
This filter creates an effect that looks like metal with a reflection in
the mirrored ground, and an interesting drop shadow.
The filter is derived from the “ Cool Metal ” script
( File → Create → Logos → Cool Metal in the image window),
which creates a logo from a text as shown above.
 16. 12. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Cool Metal .  16. 12.3. Options Figure 17. 400. “ Cool Metal ” options Effect size (pixels )
This is actually the font size option of the
“ Cool Metal ” Script-Fu script. Some internal values
will be set in relation to this size , for feathering, blurring,
embossing, and creating ripple patterns.
Background color
The color of the background layer added by the filter.  When you
click in the color swatch button, the color select dialog pops up.
Gradient
The default gradient to create the cool metal is
“ Horizon 1 ” .  Clicking in the gradient button will
open a simplified gradient
dialog , where you can select any other gradient.
Gradient reverse
By default, the selected gradient will be applied from top to
bottom. When this option is checked , the direction will be
reversed.
16.12.4. Filter details
At least some of the filter effects should be described briefly: how the
filter creates the reflection and this nice shadow, or rather, how you
can reproduce these effects manually. In fact, the only trick is to know
which tool to use...
Making the reflection
Assuming that the alpha has been filled with a gradient, then:
Create a new layer containing the area you want to mirror, for
example Copy and
Paste the area in a new
layer.
To make the reflection look more natural, scale down the layer (the
filter resizes to 85% of the original height). You can do this e.g.
using Scale Layer command or
the Scale Tool .
Then flip the layer vertically
and move it down.
Now add a layer mask ,
fill the layer mask with a
gradient (for instance white
or gray to black), and, of course,
apply the layer mask .
Making the shadow
Fill the alpha with black, for instance via
Duplicate Layer
and Alpha to
Selection , then
shrink and slant the layer, e.g. using the
Perspective tool,
and apply a Gaussian Blur to
the layer.
16.11. Comic Book 16. 13. Frosty
 Report an error in Bugzilla  13. 2. Difference Clouds 13. 2. Difference Clouds 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 2. Difference Clouds 13. 2. 1. Overview Figure 17. 281. Example of Difference Clouds Filter “ Difference Clouds ” applied Difference Clouds command changes colors
partially in cloud-like areas: The filter renders
Solid Noise cloud in an
automatically created new layer, and sets the layer mode to
Difference ,
then merges this layer over the specified image.
Before merging the layer, this script opens the dialog of the Solid
Noise plug-in which allows to control its effect.
If the image is in indexed colors, this menu entry is grayed out and
unavailable.
 13. 2. 2. Activate the filter
This filter is found in the image window menu under
Filters → Render → Clouds → Difference Clouds... .  13. 2.3. Options
This script does not have its own dialog window but invokes the
Solid Noise filter's dialog.
13. Rendering Filters 13.3. Fog
 Report an error in Bugzilla 
4. 14. Distort 4.14. Distort 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 14. Distort Figure 16.37. Example of using Distort on a selection
An image with a selection
After “ Distort ”
The “ Distort ” command deforms the selection contour.
 4. 14. 1. Activating the Command
You can access this command from the image menu bar through Select → Distort... .  4. 14. 2.
Description of the “ Distort ” Dialog Window
Figure 16.38.
The “ Distort ” dialog
This command has several options which allow to increase or reduce
the deformation. It is not possible to foresee the result and you
have to experiment.
Threshold
A higher threshold shrinks the distorted selection. A lower
threshold makes the selection bigger.
If the active selection has a regular shape (e.g. rectangle or
ellipse selection), this option controls if the new outline is
more inside the original selection or more outside the original
selection.
Spread
A higher “ Spread ” increases the deformation.
Granularity
A higher “ Granularity ” increases the deformation.
Smooth
A higher “ Smooth ” decreases the deformation.
Deactivating Smooth horizontally or
Smooth vertically increases the deformation.
4.13. Border 4.15. Rounded Rectangle
 Report an error in Bugzilla  5. 7. Drop Shadow 5. 7. Drop Shadow 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 7. Drop Shadow 5. 7. 1. Overview Figure 17. 110. Example for the “ Drop Shadow ” filter Original image “ Drop Shadow ” applied
(white background layer added manually)
This filter adds a drop-shadow to the current selection or to the image
if there's no active selection . Optional the filter resizes the image if
that's necessary for displaying the shadow.
You may choose the color, position, and size of the shadow.
Please note that the filter does not add a background layer to make the
shadow visible. The shadow's background is transparent. The white
background in the above example has not been created by the filter,
instead it has been added later to let you see the shadow.
5. 7. 2. Activate the filter
You can find this filter in the image menu menu through
Filters → Light and Shadow → Drop Shadow .
5. 7.3. Options Figure 17. 111. “ Drop Shadow ” filter options Offset X, Offset Y
The layer containing the drop shadow will be moved horizontally
by X pixels, vertically by Y pixels. So, X and Y offset
determine where the shadow will be placed in relation to the
image. High values make the imaginary source of light look like
it's far away in horizontal or vertical direction, and low
values will make it look closer to the image.
The offsets may be negative, leading to a shadow on the left of
the selection if offset X & lt; 0, or above the selection if offset
Y & lt; 0.
If there's no active selection , you must have Allow
resizing enabled to see any effect.
Blur radius
After creating the shadow, a
Gaussian blur with the
specified radius is applied to the shadow layer, resulting in the
realistic appearance of the drop shadow. It may be necessary to
enable Allow resizing , since blurring extends
the shadow.
Color
The shadow may have any color. Just click on the button, and
select a color when the color selector pops up .
Figure 17.112. “ Drop Shadow ” color example Opacity
The shadow's opacity is just the opacity of the new layer
containing the shadow (see
Section 1.1, “Layer Properties” ). It defaults to 80%, but
you may select any other value from 0 (full transparency) to 100
(full opacity) here. After applying the filter to an image you can
change the opacity in the layers
dialog .
Allow resizing
If enabled, the filter will resize the image if that is needed to
make place for the shadow. The new size depends on the size of the
selection , the blur radius, and the shadow offsets.
5.6. Supernova 5. 8. Perspective
 Report an error in Bugzilla  4. 6. Erase Every Other Row 4.6. Erase Every Other Row 4. Distort Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 6. Erase Every Other Row 4. 6. 1. Overview Figure 17. 44.
Example for the “ Erase Every Other row ” filter
Original image “ Erase Every Other row ” applied
This filter not only can erase each other row or column of the active
layer but also can change them to the background color.
 4. 6. 2. Activating the filter
This filter is found in the image window menu under
Filters → Distorts → Erase Every Other Row .  4. 6.3. Options Figure 17. 45. “ Erase Every Other row ” options
These options are self-explanatory. Only one remark: if the active
layer has an Alpha channel , erased rows or
columns will be transparent. If it doesn't have an Alpha channel (then
its name is in bold letters in the Layer Dialog), the Background color
of the toolbox will be used.
4.5. Engrave 4.7. IWarp
 Report an error in Bugzilla 
16. 13. Frosty 16.13. Frosty 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 13. Frosty 16. 13. 1. Overview Figure 17. 401. Example for the “ Frosty ” filter The “ Frosty ” filter applied The “ Frosty ” logo
This filter is derived from the “ Frosty ” logo script
( File → Create → Logos → Frosty
in the image window), which creates a frozen logo like the example above.
The filter adds this frosty effect to the alpha, that is the area of the
active layer defined by the non-transparent pixels (think of it as a
“ selection by visibility ” ). The filter effect will always
be applied according to the alpha values.
Note
Unlike the most alpha to logo filters, the “ Frosty ”
filter will not resize the image to the active
layer's size.
 16.13. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Frosty .  16. 13.3. Options Figure 17. 402. “ Frosty ” options Effect size (pixels ) Figure 17.403. “ Effect size ” examples Effect size 10 Effect size 200 Effect size 400 Background color
This color is used to fill the background layer created by the
filter. It defaults to white.  When you click on the color button ,
a color selector pops up where you can select any other color.  16. 12. Cool Metal 16. 14. Glossy
 Report an error in Bugzilla  11. 5. Fuzzy Border 11. 5. Fuzzy Border 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 5. Fuzzy Border 11. 5. 1. Overview Figure 17. 224. Example for the “ Fuzzy Border ” filter Original image “ Fuzzy Border ” applied
This filter adds a cool fading border to an image. The border will look
jagged and fuzzy, and you can specify color and thickness of the fading
border. Optionally you may add a shadow to the image.
 11. 5. 2. Activate the filter
You can find this filter in the image window menu through
Filters → Decor → Fuzzy Border .  11. 5.3. Options Figure 17. 225. “ Fuzzy Border ” options Color
Clicking on this button brings up the color selector dialog that
allows you to choose the border color.
Border size
Here you can set the thickness of the fuzzy border, in pixels.
Maximum is 300 pixels, regardless of the image width or height.
Blur border
If checked, the border will be blurred. The example below shows
the effect of blurring:
Figure 17.226. “ Blur border ” example “ Blur ” checked “ Blur ” unchecked Figure 17.227. “ Blur border ” zoomed (1600%) “ Blur ” checked “ Blur ” unchecked Granularity
The border's granularity is almost the size of pixel blocks spread
to create the effect of a jagged and fuzzy border.
Figure 17.228. Granularity example (without blurring) Granularity 1 (min) Granularity 4 (default) Granularity 16 (max) Add shadow
If checked, the filter will also create a shadow at the border.
Figure 17.229. “ Add shadow ” example “ Add shadow ” checked, shadow weight 100%
(default shadow weight).
“ Add shadow ” with shadow weight 10%.
“ Add shadow ” unchecked (default)
Shadow weight
If Add shadow is checked,
you may set the shadow opacity here. Defaults to 100% (full
opacity).
Work on copy
If checked, the filter creates a new window containing a copy of
the image with the filter applied. The original image remains
unchanged.
Flatten image
If unchecked, the filter keeps the additional layers it used to
create the border and the shadow (if demanded). Default is to
merge down all layers.
11.4. Coffee Stain 11. 6. Old Photo
 Report an error in Bugzilla 
16. 14. Glossy 16.14. Glossy 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 14. Glossy 16. 14. 1. Overview Figure 17. 404. Example for the “ Glossy ” filter The “ Glossy ” filter The “ Glossy ” logo
This filter applies gradients and patterns to the alpha. A slight 3D
effect will be added using a bump map, and optionally the filter adds a
drop shadow .
Note
Here, as a language shortcut, we use alpha to
mean the area of the active layer defined by the non-transparent
pixels. You may think of it as a selection “ by
visibility ” . Applying any effect “ to the alpha ”
just means to apply this effect to all visible pixels of the active
layer.
The filter is derived from the “ Glossy ” script
( File → Create → Logos → Glossy in the image window),
which creates a logo (see above) with a glossy outlook when used with
the default options, thus the name.
This filter only works if the active layer has an alpha channel .
Otherwise, the menu entry is insensitive and grayed out. Warning
The image will always be resized to the active layer's size.
 16. 14. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Glossy .  16. 14.3. Options Figure 17. 405. “ Glossy ” options Blend gradient (text)
By default, the filter will fill the alpha with a
gradient blend . Clicking on
the swatch button will open a simple
gradient dialog , where
you may select any gradient. “ Text ” refers to the
“ Glossy ” logo , which creates a logo from a text , and
is meaningless here.
When Text gradient reverse is checked, the
alpha will be filled with a gradient blend starting at the bottom.
Pattern (text)
When Use pattern for text instead of gradient
is checked , the alpha will be filled with a pattern. You can open
a patterns dialog to
select a pattern of your choice by clicking on the
Browse button. The preview area on the left will produce a popup preview of the current pattern when pressed.
Outline size
This is the size of a kind of border, realised with a layer
containing an enlarged copy of the alpha (details see below).
Blend gradient (outline); Pattern (outline)
Just like the “ text ” options for the active layer,
these options specify the gradient or pattern (when Use
pattern for outline instead of gradient is checked )
used to fill the outline area.
Use pattern overlay
When checked, the original, not enlarged alpha of the outline
layer will be filled with the specified pattern using the overlay
mode , so that the
pattern and the previous contents (pattern or gradient) will be
merged.
Again, clicking on Browse button will open
a patterns dialog ,
pressing the preview icon will produce a popup preview of the
current pattern .
Default bumpmap settings
This option does nothing, the filter will always apply a
bump map .
Background color
The color of the background layer added by the filter.  When you
click on the color button , a
color select dialog pops
up. 
Shadow
Optionally the filter creates a layer containing a
drop shadow . The
shadow layer will be moved Shadow X offset
pixels to the right and Shadow Y offset
pixels down. Note that this may enlarge the image, while the
background layer will keep the size of the active layer.
16.14.4. Filter details
The numerous options may give the impression that this is a very
complicate filter, but actually it is fairly simple. The interesting
part is how the filter handles the active layer and the outline layer:
In the active layer, the filter creates a
selection from the
alpha channel and fills the selection with the specified gradient
blend or pattern.
Then a new “ outline ” layer below the active layer will be
created in a similar way: First, the active layer's alpha will be used
to make a selection. But before filling the selection with a gradient or
a pattern, the selection will be
enlarged by Outline
size pixels.
When you filled both layers with the same pattern or gradient blend, you
will still see a border ( “ outline ” ), because
a 3D effect will be applied to the outline layer using the active
layer as a bump map ;
the layer mode of
the active layer will be set to “ Screen ” .
The last (optional) step is to fill the outline layer with a pattern,
using the “ overlay ” layer
mode . This will combine
the pattern with the pattern or gradient used before. To learn more
about the result of using the overlay mode, see the description in
Section 2, “Layer Modes” .
16.13. Frosty 16.15. Glowing Hot
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16. 15. Glowing Hot 16. 15. Glowing Hot 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 15. Glowing Hot 16. 15. 1. Overview Figure 17. 406. Example for the “ Glowing Hot ” filter The “ Glowing Hot ” filter The “ Glowing Hot ” logo
This filter adds a glowing hot metal effect to the alpha (that is to
these areas of the active layer defined by the non-transparent pixels).
The filter is derived from the “ Glowing Hot ” script
( File → Create → Logos → Glowing Hot in the image window),
which creates a glowing text logo (see above).
The filter simulates a red-hot, a yellow-hot, and a white-hot area -
each color representing a different metal temperature -; the alpha's
outline shines through the glowing. Warning
The image will always be resized to the active layer's size.
 16. 15. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Glowing Hot .  The filter only works if the active layer has an alpha channel .
Otherwise, the menu entry is insensitive and grayed out.
16.15.3. Options Figure 17. 407. “ Glowing Hot ” options Effect size (pixels * 3)
This is actually the font size option of the “ Glowing
Hot ” logo . The value is used to calculate the size of the
feathering border (cf Section 4.9, “Feather” )
before the alpha is filled with red, yellow, and white. These
feathered colors make the hot metal effect.
Figure 17.408. Effect size examples Effect size 50 Effect size 350 Background color
This is the color used to fill the “ Background ”
layer; it defaults to black (7,0,20). Click on the button to open
a color selector , if you want to choose a different color.
16.15.4. Filter details
To create the glowing effect (red-hot, yellow-hot, and white-hot area),
the alpha is feathered and then filled with the respective color, from
red to white with decreasing feather sizes and color intensities in the
feathered area.
The illustration below shows the “ hot metal ” colors
and the width of the feathering border in percent of
“ Effect size ” (these are the values the filter
actually uses).
Figure 17.409. Effect size
Glowing hot metal colors and their relative feather sizes
In the example images you can see how the alpha's outline shines through
the glowing. This is achieved with a alpha filled with black as top
layer, where the layer
mode is set to overlay .
Using a black overlay layer won't change pure white, but darkens light
colors at the alpha's edges so that the outline appears.
16.14. Glossy 16.16. Gradient Bevel
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16. 16. Gradient Bevel 16. 16. Gradient Bevel 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 16. Gradient Bevel 16. 16. 1. Overview Figure 17. 410. Example for the “ Gradient Bevel ” filter “ Gradient Bevel ” applied Caution
Sorry, there is no documentation for this filter as yet.
 16. 16. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Gradient Bevel .  16. 16.3. Options Figure 17. 411. “ Gradient Bevel ” options Border size (pixels)
TODO
Bevel height (sharpness)
TODO
Bevel width
TODO
Background color
TODO
16. 15. Glowing Hot 16. 17. Neon
 Report an error in Bugzilla  6. 24. New Guide (by Percent) 6. 24. New Guide (by Percent) 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 24. New Guide (by Percent) The New Guide (by Percent) command adds
a guide to the image. The position of the guide is specified as a
percentage of the canvas Height and Width.
Tip
You can add guides to the image more quickly by simply clicking and
dragging guides from the image rulers and positioning them where you
would like. Guides you draw with click-and-drag are not as precisely
positioned as those you draw with this command, however.
 6. 24. 1. Activate the Command
You can access this command from the image menubar through
Image → Guides → New Guide (by Percent) .  6. 24. 2. “ New Guide (by Percent) ” Options
When you select this menu item, a dialog opens, which allows you to set
the Direction and Position , by
percent, of the new guide.
Figure 16.83. The “ New Guide (by Percent) ” Dialog Direction
You can choose the Direction of the guide,
either Horizontal or
Vertical , by using the drop-down list.
Position
You can also choose the Position of the
new guide. The coordinate origin is in the upper left corner of
the canvas.
6. 23. New Guide 6.25. New Guides from Selection  Report an error in Bugzilla  6. 23. New Guide 6.23. New Guide 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 23. New Guide
The New Guide command adds a guide to
the image. Tip
You can add guides to the image more quickly , but less accurately, by
simply clicking and dragging guides from the image rulers and
positioning them where you would like.  6. 23. 1. Activate the Command
You can access this command from the image menubar through
Image → Guides → New Guide 
6.23.2. “ New Guide ” Options
When you select New Guide , a dialog opens,
which allows you to set the Direction and
Position , in pixels, of the new guide more
precisely than by using click-and-drag.
Figure 16.82. The “ New Guide ” Dialog Direction
You can choose the Direction of the guide,
either Horizontal or
Vertical , by using the drop-down list.
Position
The coordinate origin for the Position is
the upper left corner of the canvas .
6. 22. Guides 6.24. New Guide (by Percent)
 Report an error in Bugzilla  6. 25. New Guides from Selection 6. 25. New Guides from Selection 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 25. New Guides from Selection The New Guides from Selection command adds
four guide lines, one for each of the upper, lower, left and right
edges of the current selection. If there is no selection in the
current image , no guides are drawn.
 6. 25. 1. Activating the Command
You can access this command from the image menubar through
Image → Guides → New Guides from Selection .  6. 24. New Guide (by Percent) 6. 26. Remove all guides
 Report an error in Bugzilla  6. 26. Remove all guides 6.26. Remove all guides 6. The “ Image ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  6. 26. Remove all guides
The Remove all Guides command removes all guides
from the image. Clicking-and-dragging one or two guides onto a ruler
is a quicker way to remove them. This command is useful if you have
positioned several guides.
 6. 26. 1. Activate the Command
You can access this command from the image menubar through
Image → Guides → Remove all guides .  6. 25. New Guides from Selection 6. 27. Configure Grid
 Report an error in Bugzilla  13. 19. Lava 13.19. Lava 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 19. Lava 13. 19. 1. Overview Figure 17. 332. Example for the “ Lava ” filter Original image “ Lava ” applied (on a selection)
 13. 19. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Lava .  13. 19.3. Options
Figure 17. 333. “ Lava ” options Seed
TODO
Size
TODO
Roughness
TODO
Gradient
TODO
Keep selection
TODO
Separate layer
TODO
Use current gradient
TODO
13.18. Gfig 13.20. Line Nova
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13. 20. Line Nova 13.20. Line Nova 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 20. Line Nova 13.20. 1. Overview Figure 17.334. Example for the “ Line Nova ” filter Original image “ Line Nova ” applied
The Line Nova filter fills a layer with rays emanating outward from the
center of the layer using the foreground color shown in the Toolbox. The
rays starts as one pixel and grew broader towards the edges of the
layer .
Tip
This filter does not provide any option which allows you to set the
center point of lines. If you need adjust the place of the radial
lines where you want, create another transparent image and apply this
filter on it, then add it on your image. Setting large size for the
new nova image may help you not to break lines inside of your image.
 13. 20. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Line Nova .  13. 20.3. Options Figure 17.335. “ Line Nova ” options Number of lines
By using this option you can set the number of lines between 40
to 1000. The default is 200.
Sharpness (degrees)
This slider determines how much the rays will broaden towards the
edges. The range goes from 0.0 to 10.0. If set to 0.0 , nothing
will be drawn. If set to 10.0, most of the area near the edges of
the layer will be painted.
Figure 17.336. “ Line Nova ” sharpness option
From left to right: sharpness = 1; sharpness = 5;
sharpness = 10
Offset radius
Here you choose the distance, in pixels, from center to the
starting point of the rays. If set to 0.0 the rays starts from the
center. Any other value will let the starting points be on a
circle at the selected distance from the center. The maximum
distance is 2000 pixels. The default value is 100 pixels.
Figure 17.337. “ Line Nova ” offset radius option
From left to right: offset radius = 0; offset radius = 50
Randomness
If this slider is set to a value higher than 1, the starting point
for each ray differ more or less randomly from the average
starting point set as the offset radius above. With the value set
to 1, all the rays will start at the circle determined by the
offset radius. The maximum value is 2000. The default value is 30.
Figure 17.338. “ Line Nova ” randomness option
From left to right: randomness = 1; randomness = 50
13.19. Lava 13.21. Sphere Designer
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16. 17. Neon 16.17. Neon 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 17. Neon 16. 17. 1. Overview Figure 17. 412. Example for the “ Neon ” filter The “ Neon ” filter The “ Neon ” logo
This filter converts the active layer's alpha into a neon-sign like
object and optionally adds a shadow.
It is derived from the “ Neon ” Script-Fu script
( File → Create → Logos → Neon ),
which creates a text effect that simulates neon lighting.
Warning
The image will always be resized to the active layer's size.
 16. 17. 2. Activate the filter
You can find this filter in the image window menu under
Filters → Alpha to Logo → Neon .  16. 17.3. Options Figure 17. 413. “ Neon ” options Effect size (pixels * 5)
This is actually the font size option of the Neon Script-Fu
script. Some internal values will be set in relation to this font
size, for instance tube size, shadow offset, and blur radius. So
it may be a good idea to select the height of your objects as a
starting point here. ( “ pixels * 5 ” is nonsense,
ignore it.)
Background color
This is the color used to fill the “ Background ”
layer; it defaults to black .  When you click on the color swatch
button , you can choose any other color in the color selector
dialog.  Glow color
This is the color of the glowing neon tubes. The default is a
typical neon-like light blue (38,211,255). Again, a click on the
color swatch button brings up the color selector .
Create shadow
Optionally, the filter can create a drop shadow, which will have
the same shape as the alpha channel. The shadow color is black,
and cannot be modified. Unless you don't plan to remove the
background layer , you should select a different
Background color .
“ Neon ” with shadow 16.17. 4. Filter details
The filter uses two layers to achieve the neon effect:
Figure 17.414. The Neon effect The “ Neon Tubes ” layer The “ Neon Glow ” layer
The layer “ Neon Tubes ” is the active layer the filter is
applied to. The content of this layer doesn't matter. Only the alpha
channel does, especially its shape.
The “ Neon Glow ” layer below contains the glowing of the
neon light.
Optional a “ Shadow ” layer is created below, containing a
drop shadow in the same shape of the active layer's alpha channel. At
the bottom a new “ Background ” layer is created filled with
the Background color .
Overview of the Neon filter layers: 16.16. Gradient Bevel 16. 18. Particle Trace
 Report an error in Bugzilla  11. 6. Old Photo 11.6. Old Photo 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 6. Old Photo 11. 6. 1. Overview Figure 17. 230. Example for the “ Old Photo ” filter Original image “ Old Photo ” applied
This filter makes an image look like an old photo: blurred, with a
jagged border, toned with a brown shade, and marked
with spots.
 11. 6.2. Activate the filter
The filter is found in the image window menu under
Filters → Decor → Old Photo .  11. 6.3. Options Figure 17. 231. “ Old Photo ” options Defocus
If checked, a Gaussian blur
will be applied to the image , making it less clear.
Figure 17.232. Example for the “ Defocus ” option Defocus enabled Defocus disabled Border size
When you choose a border size & gt; 0, the
Fuzzy Border filter
will be applied to the image , adding a white, jagged border.
Sepia
If checked, the filter reproduces the effect of aging in old,
traditional black-and-white photographs, toned with sepia (shades
of brown). [16]
To achieve this effect, the filter desaturates the image, reduces
brightness and contrast, and modifies the color
balance. [17]
Mottle
When you check this option , the image will be marked with spots.
Figure 17.233. Example for the “ Mottle ” option
A plain white image mottled (without Defocus or Sepia)
Work on copy
If checked, the filter creates a new window containing a copy of
the image with the filter applied. The original image remains
unchanged.
[16]
See Wikipedia [ WKPD-SEPIA ] .
[17]
Compare Section 5.2, “Color Balance” .
11.5. Fuzzy Border 11. 7. Round Corners
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5.8. Perspective 5.8. Perspective 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 8. Perspective 5. 8. 1. Overview Figure 17. 113. Example for the “ Perspective ” filter Original image “ Perspective ” applied
This filter adds a perspective shadow to the selected region or
alpha -channel as a layer below the active layer . You may select
color, length and direction of the shadow as well as the distance of
the horizon.
If necessary, the filter may resize the image. But it will not add a
background to make the shadow visible.
5. 8. 2. Activate the filter
You can access this filter in the image window menu through
Filters → Light and Shadow → Perspective .
5. 8.3. Options Figure 17. 114. “ Perspective ” options Angle
The angle determines the direction of the shadow or the imaginary
source of light , respectively. Values range from 0° to 180°,
where 90° represents a light source just in front of the selection
or layer. For angles less than 90°, the shadow is at the right
side, so the light source is on the left. For angles greater than
90°, it's the other way round. Tip: think of the slider's handle
as source of light.
Figure 17.115. “ Angle ” example Angle 15° Angle 45° (default) Angle 105° (90° + 15°) Relative distance of horizon
This option determines how far away the imaginary horizon is. The
relative distance is the distance from the
ground-line of the selection or layer, the “ unit ” of
measurement is the height of the selection or layer. Value range is from 0 .1 to 24.1, where 24.1 means (nearly)
“ infinite ” . Note that the relative length
of shadow must not exceed the distance of horizon.
Figure 17.116. “ Distance of horizon ” example
Angle = 45°. Distance = 2.4. Length = 1.8.
In the example above, the yellow area is the selection the filter
is applied to. The blue line at the top represents the imaginary
horizon. The angle between the selection's ground-line and the red
line is 45°. The length of the red line is 1.8 times the height of
the yellow selection. Extended to the horizon, the length is 2.4
times the selection's height.
Relative length of shadow
With this option you can set the length of shadow with respect to
the height of the selection or layer. In the above example, the
red line represents the length of shadow, its length is 1.8
relative to the height of the yellow selection. Value range is from 0 .1 to 24.1, although the length of shadow
must not exceed the relative distance of
horizon - you can't go beyond the horizon.
Figure 17.117. “ Length of Shadow ” example Length = 1.0 (default) Length = 1.5 Blur radius
After creating the shadow, a
Gaussian blur with the specified
radius is applied to the shadow layer, resulting in the realistic
appearance of the shadow.
Figure 17.118. Blur example Blur radius = 3 (default) Without blur (blur radius = 0) Color
Of course, the default color of the shadow is black. But a click
on the button opens the color selector, where you may select
any other color. Opacity
The shadow's opacity is the opacity of the new layer containing
the shadow (see Section 1.1, “Layer Properties” ). It
defaults to 80%, but you may select any other value from 0 (full
transparency) to 100 (full opacity) here. After applying the
filter to an image you can change the opacity in the
layers dialog .
Interpolation
This drop-down list lets you choose the method of
interpolation used
when the shadow layer is transformed, for example rotated by the
specified angle. Using None will usually
result in aliasing, using any interpolation method may change the
color of the shadow in some areas. Linear is
a good choice.
Allow resizing
If enabled, the filter will resize the image if that is needed to
make place for the shadow. In the example below, the yellow area is the active selection,
background is light blue. The white area has been added after
resizing to make the shadow visible.
Figure 17.119. “ Allow resizing ” example Allow resizing Don't allow resizing 5.7. Drop Shadow 5. 9. Xach-Effect
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10. 9. Predator 10.9. Predator 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 9. Predator 10. 9. 1. Overview Figure 17. 195. Example for the “ Predator ” filter Original image “ Predator ” applied
This filter adds a “ Predator ” effect to the image. The
predator effect makes the image/selection look something like the view
the predator has in movies (kind of a thermogram and that type of
thing). This will reduce the image to edges in a few basic colors on a
dark background.
If there is an active selection , the filter effect will be applied to
the selected region, otherwise to the alpha channel (the filter will
add an alpha channel, if necessary). The filter works best on colorful
RGB images.
 10.9. 2. Activate the filter
This filter is found in the image window menu under
Filters → Artistic → Predator .  10. 9.3. Options Figure 17. 196. “ Predator ” options Edge amount
The “ predator ” filter will detect edges using the
Sobel edge detector . The
specified “ Edge amount ” will be passed to the Sobel
filter. A high value will result in detecting more edges.
Figure 17.197. “ Edge amount ” examples 4 8 16 Pixelize
If checked, the filter will simplify the image into solid-colored
squares using the Pixelise
filter before the real predator effect will be applied. You can
select the size of these squares with the option Pixel
amount , which will heavily affect the result (see
examples below).
Pixel amount “ Pixel amount ” is the size of the color blocks the
image will be simplified to if Pixelize is
checked. Actually you are decreasing the resolution with this
option. In the examples below, you can see directly how increasing
the pixel block size leads to something like
“ macro pixels ” :
Figure 17.198. “ Pixelize ” examples Disabled 4 8 16 Keep selection
If checked, the filter will be applied to the active selection.
Else, it will be applied to the active layer.
Separate layer
When this option is checked , a copy of the active layer will be
created above the active layer and the filter will be applied to
this copy, leaving the original layer untouched. If not checked,
the filter will be applied to the active layer.
10.9.4. Filter algorithm
Since this filter delegates the essential parts to two or three other
filters the algorithm is very simple:
Figure 17.199. Making the “ predator ” effect Original Pixelize Min RGB Edge detection The original image.
Optionally, the filter
pixelizes the image: it
renders the image by using color blocks instead of pixels, thus
reducing the image resolution.
The colors will be reduced to pure red, green, blue (and possibly
gray colors), using the minimal
RGB channel for every pixel.
Applying the Sobel edge
detecting filter, the image will be reduced further on to
edges, usually on a black background, with very few colors.
10.8. Photocopy 10.10. Softglow
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7. 20. The “Reverse Layer Order” command 7.20. The “ Reverse Layer Order ” command 7. The “ Layer ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  7. 20. The “ Reverse Layer Order ” command This command is self-explanatory. 7. 20.1. Activating the command
From the image Menu through:
Layers → Stack → Reverse Layer Order .
7.19. Layer to Bottom 7.21. The “ Mask ” Submenu
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15. 4. Rippling 15.4. Rippling 15. Animation Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. 4. Rippling 15. 4. 1. Overview Figure 17. 361. Example for the “ Rippling ” filter Original image A “ Rippled ” frame
 15. 4. 2. Activating the filter
This filter is found in the image window menu under
Filters → Animation → Rippling .  15. 4.3. Options
Figure 17. 362. “ Rippling ” options Rippling strength
TODO
Number of frames
TODO
Edge behavior
TODO
15.3. Burn-In 15.5. Spinning Globe
 Report an error in Bugzilla  11. 7. Round Corners 11. 7. Round Corners 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 7. Round Corners 11. 7. 1. Overview Figure 17. 234. Example for the “ Round Corners ” filter Original image “ Round Corners ” applied
This filter rounds the corners of an image, optionally adding a
drop-shadow and a background layer .
The filter works on RGB and grayscale images that contain only one
layer. It creates a copy of the image or can optionally work on the
original. It uses the current background color to create a background
layer.
 11.7. 2. Activate the filter
This filter is found in the image window menu under
Filters → Decor → Round Corners .  11. 7.3. Options Figure 17. 235. “ Round Corners ” options Edge radius
Rounding corners is done by selecting a quarter of a circle at
every corner and removing the area not covered by this selection.
The “ edge radius ” is the radius of the constructing
circle.
In the examples below, the filter was applied to a 100x100 pixels
image, with varying edge radius. For radius = 50, the four
quadrants just form a circle with diameter = 100, which exactly
fits into the original image outline. A radius greater than 50 is
possible, but look what happens...
Figure 17.236. Edge radius examples
A 100x100 pixels image, edge radius: 15 (default).
Edge radius: 35. Edge radius: 50. Edge radius: 65. Ouch! Add drop-shadow
When this option is checked , the filter will cast a shadow behind
your image after rounding the image corners.
Shadow X/Y offset
X and Y offset determine where the shadow will be placed in
relation to the image. Offset is measured in pixels. High values
make the shadow look like it's far away , and low values will make
it look closer to the image.
Figure 17. 237. Shadow offset examples
Shadow X offset: 8, Y offset: 8 (default).
Shadow X offset: 16, Y offset: 4.
Note that the shadow offsets as well as the blur radius are
limited to background area.
Blur radius
When Add drop- shadow is checked, you may
select a blur radius, which will be used by the
Drop Shadow filter.
The image will be enlarged in both dimensions depending on the
blur radius and the shadow offsets.
Add background
When you check this option (it is checked by default), the filter
will add a background layer below the existing layer, filled with
the current background color . The size of this new layer depends
on the blur radius and the shadow offsets.
Work on copy
If checked, the filter creates a new window containing a copy of
the image with the filter applied. The original image remains
unchanged.
11. 6. Old Photo 11.8. Slide
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4. 15. Rounded Rectangle 4.15. Rounded Rectangle 4. The “ Select ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  4. 15. Rounded Rectangle Figure 16.39. Example of using Rounded rectangle on a selection
An image with a selection
After “ Rounded rectangle ”
The “ Rounded Rectangle ” Script-Fu command converts an
existing selection (rectangular, elliptical or other shape) into a
rectangular selection with rounded corners. The corners can be curved
toward the inside (concave) or toward the outside (convex). To do this,
the command adds or removes circles at the corners of the selection.
 4. 15. 1. Activating the Command
You can access this command from the image menu bar through Select → Rounded Rectangle .  4. 15. 2.
Description of the “ Rounded Rectangle ” Dialog Window
Figure 16.40. The “ Rounded Rectangle ” dialog Radius (%)
You can enter the radius of the rounded corner in percent by
using a slider or a text field. This value is a percentage of
the height or the width, whichever is less.
Concave
If you check this box, the corners will be concave (curving
toward the inside), rather than convex (curving toward the
outside).
4.14. Distort 4.16. Toggle QuickMask
 Report an error in Bugzilla  8. 20. Set Colormap 8.20. Set Colormap 8. The “ Colors ” Menu  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  8. 20. Set Colormap Figure 16.161. The “ Set Colormap ” window
This command opens a dialog which allows you to select another palette
to replace the color map of your indexed image. First click in the
button with the name of the current palette (which is not the color map
of your image yet) to open the Palette Selector:
Figure 16.162. The “ Palette Selection ” dialog
Once you have chosen the wanted palette, click the
OK button in the “ Set Palette ”
dialog to replace the image colormap.
8. 20. 1. Activate the command
This command is found in the image window menu under
Colors → Map → Set Colormap .
8.19. Rearrange Colormap 8. 21. Alien Map
 Report an error in Bugzilla  11. 8. Slide 11.8. Slide 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 8. Slide 11. 8. 1. Overview Figure 17. 238. Example for the “ Slide ” filter Original image “ Slide ” applied
This filter makes your image look like a slide, by adding a slide-film
like black frame, sprocket holes, and labels.
If necessary, the image will be cropped to fit into an aspect ratio of
width : height = 3:2. If image width is greater than image height,
black frames will be added at the top and the bottom of the image, else
the frames will be added on the left and right sides . You may select
the color as well as the font of the text appearing on the frames. The
current background color will be used for drawing the holes.
The script only works on RGB and grayscale images that contain one
layer. Otherwise the menu entry is insensitive and grayed out.  11. 8.2. Activate the filter
The filter is found in the image window menu under
Filters → Decor → Slide .  11. 8.3. Options Figure 17. 239. “ Slide ” options Text
A short label that will be displayed in the top and bottom (or
the left and right) of the frame. The text must be really short.
Number
Here you may enter a text for simulating consecutive numbers. Two
numbers will be displayed: this number and this number with the
character “ A ” appended.
Font
Clicking on this button opens the
Font dialog , where you
can choose a font for the text on the frame.
Fontcolor
Clicking on this button brings up a color selection dialog that
allows you to choose the color of the text.
Work on copy
If checked, the filter creates a new window containing a copy of
the image with the filter applied. The original image remains
unchanged.
11. 7. Round Corners 11. 9. Stencil Carve
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11. 10. Stencil Chrome 11.10. Stencil Chrome 11. Decor Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  11. 10. Stencil Chrome 11. 10. 1. Overview Figure 17. 244. Example for the “ Stencil Chrome ” filter Original image “ Stencil Chrome ” applied
This filter provides a state of the art chrome effect. The source image
must be an image in grayscale mode , containing a single layer without
alpha channel. This layer is used as mask ( “ stencil ” ) for
the chrome effect.
The filter creates a new image with the chrome effect applied to the
source image or, if a selection exists, to the selection of the source
image (a nice background is added too).
 11. 10. 2. Activating the filter
This filter is found in the image window menu under
Filters → Decor → Stencil Chrome .  Tip
If this command remains grayed out although the image is in grayscale
mode, check for an Alpha channel and delete it.
11. 10.3. Options Figure 17. 245. “ Stencil Chrome ” options Chrome saturation, Chrome lightness
Use this option to control how
saturation and
lightness of the “ Chrome ” layer are adjusted.
Negative values decrease saturation and lightness respectively.
Chrome factor
This factor lets you adjust offsets, feather radius, and brush
size used to construct the “ Chrome ” and
“ Highlight ” layer (and the “ Drop Shadow ”
as well).
Change with caution, decreasing this value may make the chrome
effect worse. The default factor 0.75 seems to be a good choice .
Environment map
The environment map is an image that is added as some kind of
“ noise ” to the source. The effect is best to see if
you use a simple map with some obvious shapes:
Using a simple environment map
The environment map must be an image in grayscale mode too. Size
doesn't matter, the environment map is scaled to the size of the
source image.
Highlight balance
This color is used to modify the
color balance of
the “ Highlight ” layer : the amount of red, green, and
blue colors is increased according to the corresponding values of
the specified option.
Avoid colors with red, green or blue value & gt; 230.
Chrome balance
Same as above, but modifies the
color balance of
the “ Chrome ” layer .
Chrome white areas
If checked ( this is the default), the source image is used as
mask. If unchecked, the inverted source image
is used .
11.10.4. How to create the chrome effect
The following section provides a brief and simplified description of how
the script (actually this filter is a Script-Fu) creates the chrome
effect.
If you apply the filter to your source images and then look at the
layer dialog of the resulting
image, you will see that there are two main layers which make up the
chrome effect: the “ Chrome ” layer and the
“ Highlight ” layer . These layers are created as follows:
The script constructs a somewhat simplified and blurred layer from
the source image (from the inverted source image if
Chrome white areas is unchecked).
The Chrome factor controls the appearance of
this layer.
The (scaled) environment map is blurred and merged into the above
layer with 50% opacity. (Do you spot the cat in the introducing
example ?)
Merging the environment map
The brightness (value) of the layer is modified according to a
spline-based intensity curve.
Modifying the intensity curve
A layer mask is added, initialized with the source image
(the “ Chrome Stencil ” ). This is the
“ Chrome ” layer before the final step.
The “ Highlight ” layer is a copy of the
“ Chrome ” layer where the layer mask is stroked with a
white brush.
Chrome and Highlight base
For both layers the color balance is modified (according to
Highlight balance and
Chrome balance ), increasing the amount of
red, green, and blue , with emphasis on highlights.
Additionally, saturation and lightness of the “ Chrome ”
layer are modified (controlled by
Chrome saturation and
Chrome lightness ).
Chrome and Highlight layer
Now add a drop shadow and a background layer and you get the
Example image
for the “ Stencil Chrome ” filter .
11.9. Stencil Carve 12. Map Filters
 Report an error in Bugzilla  15. 5. Spinning Globe 15. 5. Spinning Globe 15. Animation Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. 5. Spinning Globe 15. 5. 1. Overview Figure 17. 363.
Example for the “ Spinning Globe ” filter: original image
Original image Figure 17.364.
Example for the “ Spinning Globe ” filter: filter applied
3 (of 10) “ Spinning Globe ” frames (on a white
background)
 15. 5. 2. Activating the filter
This filter is found in the image window menu under
Filters → Animation → Spinning Globe .  15. 5.3. Options
Figure 17. 365. “ Spinning Globe ” options Frames
TODO
Turn from left to right
TODO
Transparent background
TODO
Index to n colors
TODO
Work on copy
TODO
15.4. Rippling 15.6. Waves
 Report an error in Bugzilla  13. 22. Spyrogimp 13.22. Spyrogimp 13. Rendering Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  13. 22. Spyrogimp 13.22. 1. Overview Figure 17.341. Example for the “ Spyrogimp ” filter Original image “ Spyrogimp ” applied
 13. 22. 2. Activating the filter
This filter is found in the image window menu under
Filters → Render → Spyrogimp .  13. 22.3. Options
Figure 17.342. “ Spyrogimp ” options Type
TODO
Shape
TODO
Outer teeth
TODO
Inner teeth
TODO
Margin (pixels)
TODO
Hole ratio
TODO
Start angle
TODO
Tool
TODO
Brush
TODO
Color method
TODO
Color
TODO
Gradient
TODO
13.21. Sphere Designer 14. Web Filters
 Report an error in Bugzilla  16. 18. Particle Trace 16.18. Particle Trace 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 18. Particle Trace 16. 18. 1. Overview Figure 17. 415. Examples for the “ Particle Trace ” filter The “ Particle Trace ” filter The “ Particle Trace ” logo
To get such images, open a new image with a transparent background,
create selections, fill them with any color, and apply filter.
This filter adds an effect, reminding of particle
traces in a bubble chamber of nuclear physics, to the active layer
alpha .
 Warning
The image will always be resized to the active layer's size.
The filter is derived from the “ Particle Trace ” logo script
( File → Create → Logos → Particle Trace ),
which creates the text effect shown in the example above.   16. 18. 2. Activate the filter
You can find this filter in the image window menu under
Filters → Alpha to Logo → Particle Trace .  16. 18.3. Options Figure 17. 416. “ Particle Trace ” options Border size (pixels)
Actually this option is the text layer's border of the
“ Particle Trace ” Script-Fu Logo (hence the misleading
name). Here it determines the width of the white shadow's
feathering .
Hit rate
This option sets the amount of light points produced by the
Noise filter and thus the
amount of points converted to
sparkles . The value ranges
from from 0.0 to 1.0 , but some values may be not useful:
Figure 17.417. “ Hit rate ” examples Hit rate 0.10 Hit rate 0.25 Hit rate 0.40 Edge width
Along the edge of the alpha , a new area will be created with
radius “ Edge width ” (compare
Section 4.13, “Border” ). This area will also be
filled with the “ Base color ” , but will be a bit
darker.
Edge only
If checked, the filter effect will be applied to the edge of the
alpha channel only and the area of the alpha channel will be
cleared .
“ Edge only ” activated Base color
This color is used to fill the area defined by the active layer's
alpha channel. It defaults to a very dark green.  As usual,
clicking on the color swatch button opens a color selector where
you can choose any other color.  Background color
This color is used to fill a new background layer. Note that above
the background layer there is a white shadow layer which has
opacity set to 90%, so you will see the background color only
partially. If the “ Edge only ” option is enabled, the
area of the alpha channel will be cleared and you will see the
background color .  Again, when you click on the color swatch
button , a color selector pops up where you can select any color.  The active layer (top) and the filter layers below
16.18. 4. Filter details
The filter adds noise to the
alpha and then turns the spots into
sparkles . Then it adds a
feathered white shadow.
16.17. Neon 16.19. Textured
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16. 19. Textured 16.19. Textured 16. Alpha to Logo Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  16. 19. Textured 16. 19. 1. Overview Figure 17. 418. Example for the “ Textured ” filter “ Textured ” applied Caution
Sorry, there is no documentation for this filter as yet.
 16. 19. 2. Activate the filter
This filter is found in the image window menu under
Filters → Alpha to Logo → Textured .  16. 19.3. Options Figure 17. 419. “ Textured ” options Border size (pixels)
TODO
Pattern
TODO
Mosaic tile type
TODO
Background color
TODO
Starting blend
TODO
Ending blend
TODO
16.18. Particle Trace Keys and Mouse Reference
 Report an error in Bugzilla  2. 7. Tileable Blur 2.7. Tileable Blur 2. Blur Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 7. Tileable Blur 2. 7. 1. Overview Figure 17. 18. Example for the “ Tileable ” filter Original Filter “ Tileable Blur ” applied
This tool is used to soften tile seams in images used in tiled
backgrounds. It does this by blending and blurring the boundary between
images that will be next to each other after tiling.
Tip
If you want to treat only images borders, you can't apply filter
to the whole image. The solution to get the wanted effect is as
follows:
Duplicate layer
( Layer → Duplicate Layer )
and select it to work on it.
Apply “ Tileable Blur ” filter with a 20 pixels radius
to this layer.
Select all
( Ctrl + A ) and
reduce selection
( Selection → Shrink )
to create a border with the wanted width.
Give a feathered border to the selection by using
Selection → Feather .
Delete selection with
Ctrl + K .
Merge layers with
Layer → Merge down .
 2. 7. 2. Activate the filter
You can find this filter in the image menu under
Filters → Blur → Tileable Blur .  2. 7.3. Options Figure 17. 19. “ Tileable Blur ” filter options Radius
The bigger the radius, the more marked is the blur. By selecting
Horizontal and Vertical ,
you can make the horizontal and vertical borders tileable.
Blur vertically, Blur horizontally
These options are self-explanatory.
Blur type Choose the algorithm to be applied: IIR for photographic or scanned images. RLE for computer-generated images. 2.6. Pixelise 3. Enhance Filters
 Report an error in Bugzilla  15. 6. Waves 15.6. Waves 15. Animation Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  15. 6. Waves 15. 6. 1. Overview Figure 17. 366. Example for the “ Waves ” filter Original image A “ Wave ” frame
 15. 6. 2. Activating the filter
This filter is found in the image window menu under
Filters → Animation → Waves .  15. 6.3. Options
Figure 17. 367. “ Waves ” options Amplitude
TODO
Wavelength
TODO
Number of frames
TODO
Invert direction
TODO
15.5. Spinning Globe 15. 7. Optimize
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10. 12. Weave 10.12. Weave 10. Artistic Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  10. 12. Weave 10. 12. 1. Overview Figure 17. 213. Example of Weave Filter “ Weave ” applied
The Weave command is a Script-Fu script
which creates a new layer filled with a weave effect and adds it to
the image as an overlay or bump map. The result of the image looks
as if it were printed over woven ribbons of paper, thin wooden sheet,
or stripped bamboo.
If the image is in indexed colors, this menu entry is grayed out and
unavailable.
This filter adds a “ Multiply ” mode layer upon the layer
where you activate this command. The weave texture is rendered in gray
levels.
 10. 12. 2. Activate the filter
This filter is found in the image window menu under
Filters → Artistic → Weave... .  10.12.3. Options Figure 17. 214. “ Weave ” filter options
For to make coarse mesh texture, increase the ribbon spacing and/or
decrease the ribbon width.
For to strain ribbons hard, decrease the shadow depth.
Ribbon width
With this option you can set the tape width in pixel between
0.0 and 256.0. In default, 30.0 pixels is set.
Ribbon spacing
With this option you can set the distance to the neighboring
ribbon or the size of black square hole in pixel between 0.0
and 256.0. In default, 10.0 pixels is set.
Shadow darkness
With this option you can set the darkness at crossings of lower
ribbon in percentage. Lower value shows ribbons thinner. 75. 0
percent is the default value.
Shadow depth
With this option you can set the bent strength of ribbons in
percentage. Higher value shows ribbons more wavy, lower value
for flat surface. The actual effect is limited by the
Shadow darkness .
75. 0 percent is the default value.
Thread length
With this option you can set the regularity of stripe texture.
If this value is shorter than the summary of the ribbon width
and twice of the ribbon spacing, the surface of ribbon becomes
speckled. Set this value in pixel on range between 0.0 to
256.0. The default value is 200.0.
Thread density
With this option you can set the density of fiber-like parallel
short stripes on the surface of ribbons. To populate stripes
increase this value. 50. 0 percent is the default value.
Thread intensity
With this option you can set the opacity of stripe texture.
Lower value shows threads vague. To clear off threads set the
value to 0.0 percent. The default value is 100 .0 percent.
10.12.4. Another usage Figure 17.215. Adding a lattice using “ Weave ” texture
Narrower the ribbon width, wider the ribbon spacing, and
filled with the “ Wood #1 ” pattern.
This texture can be a lattice that you can see the original image
through its mesh holes. Add a new, transparent layer over the active
layer for the lattice, and apply this filter. Select a black regular
square in the texture layer using the
Select By Color tool,
then delete black squares in selection on the texture layer to be chink
holes. Reverse the selection, and activate the transparent layer so
that you can fill the lattice surface with a pattern, then drag and drop
your favorite pattern over the image window.
10.11. Van Gogh (LIC) 11. Decor Filters
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5. 9. Xach-Effect 5. 9. Xach-Effect 5. Light and Shadow Filters  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 9. Xach-Effect 5. 9. 1. Overview Figure 17. 120. Example for the “ Xach-Effect ” filter Original image “ Xach-Effect ” applied
This filter adds a subtle translucent 3D effect to the selected region
or alpha channel . This 3D effect is achieved by
Highlighting the selection: a new layer ( “ Highlight ” )
will be created above the active layer , filled with the highlight
color. Then a layer mask will
be added to that layer making the unmasked pixel partially
transparent.
Highlight layer with layer mask
Painting the selection's left and top edges with the highlight
color: for that the “ Highlight ” layer will be extended
by one pixel left and up. These small areas will be opaque.
Creating a drop shadow
at the bottom right side of the selection.
You may vary these default settings, for example select different colors
for highlight or shadow and change amount and directions of offsets.
 5. 9.2. Activate the filter
The filter is found in the image window menu under
Filters → Light and Shadow → Xach-Effect .  5. 9.3. Options
There are two groups of options, each controlling the highlight or the
shadow, and a checkbox for the selection behaviour.
Figure 17.121. “ Xach-Effect ” options Highlight X offset, Highlight Y offset
The selection's left and top edge are painted with the highlight
color. The highlight offset is the size (width or height) of the
respective area. If offset is less than 0 ( this is the default),
the left (X offset & lt; 0) or top (Y offset & lt; 0) area will be
colored. If offset is greater than 0, the right (X offset & gt; 0)
or bottom (Y offset & gt; 0) area will be painted.
Highlight color
This is the color used to highlight the selected area. It defaults
to white, but clicking on the swatch button brings up a color
selector and you may select any other color.
Highlight opacity
The selection will be covered by a partially transparent area
filled with the highlight color. This option lets you set the
level of transparency. Since a
layer mask will be used,
the value ranges from 0 (full transparency) to 255 (full opacity).
The highlight opacity defaults to 66, which is equivalent to 26%.
Drop shadow options
These options work like the respective
Drop Shadow options
(without resizing). Briefly:
Drop shadow color
Click on the button to open a color selector .
Drop shadow opacity
The opacity (0% - 100%) of the layer containing the shadow.
Drop shadow blur radius
The radius used by the
Gaussian blur filter,
which will be applied to the shadow.
Drop shadow X offset, Drop shadow Y offset
Direction and amount, by which the shadow will be moved from
the selection.
Keep selection
If checked, the active selection will remain active when the
filter has been applied.
5.8. Perspective 5.10. Apply Lens
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2.5. Standalone Scripts 2.5. Standalone Scripts 2. Using Script-Fu Scripts  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  2. 5. Standalone Scripts
We will not try to describe every script in depth. Most Script-Fus are
very easy to understand and use. At the time of this writing, the
following types are installed by default:
Patterns Web page themes Logos Buttons Patterns
You will find all kinds of pattern-generating scripts here.
Generally, they are quite useful because you can add many
arguments to your own patterns.
We'll take a look at the Land script. In this script you have to
set the image/pattern size, and specify what levels of random to
use for your land creation. The colors used to generate the land
map are taken from the currently selected gradient in the gradient
editor. You must also supply values for the level of detail, land
and sea height/depth and the scale. Scale refers to the scale of
your map, just as in an ordinary road map, 1:10 will be typed as
10.
Web Page Themes
Here is clearly a practical use for scripts. By creating a script
for making custom text, logos, buttons arrows, etc., for your web
site, you will give them all the same style and shape. You will
also be saving a lot of time, because you don't have to create
every logo, text or button by hand.
Most of the scripts are quite self-explanatory, but here are some
hints:
Leave all strange characters like ' and " intact.
Make sure that the pattern specified in the script exists.
Padding refers to the amount of space around your text.
A high value for bevel width gives the illusion of a higher
button.
If you type TRUE for "Press", the button will look pushed
down.
Choose transparency if you don't want a solid background. If
you choose a solid background, make sure it is the same color
as the web page background.
Logos
Here you will find all kinds of logo-generating scripts. This is
nice, but use it with care, as people might recognize your logo as
being made by a known GIMP script. You should
rather regard it as
a base that you can modify to fit your needs. The dialog for
making a logo is more or less the same for all such scripts:
In the Text String field, type your logo name, like
Frozenriver.
In the Font Size text field, type the size of your logo in
pixels.
In the Font text field, type the name of the font that you
want to use for your logo.
To choose the color of your logo, just click on the color
button . This brings up a color dialog.
If you look at the current command field, you can watch the
script run.
Make Buttons
Under this headline you'll find two scripts that makes rectangular
beveled buttons, with or without round corners (Round Button or
Simple Beveled Button). They have a dozen parameters or so, and
most of them are similar to those in the logo scripts. You can
experiment with different settings to come up with a button you
like.
2.4. Different Kinds Of Script-Fus 2. 6. Image-Dependent Scripts  Report an error in Bugzilla  5. 2. Tool Preset Editor 5. 2. Tool Preset Editor 5. Misc. Dialogs  Català Dansk Deutsch Ελληνικά English British Español Français Italiano 日本語(Japanese) 한국어(Korean) Nederlands Norwegian Português Pусский 中文  5. 2. Tool Preset Editor Figure 15.73. The Tool Preset Editor 5. 2.1. Activating the Dialog
You can access this dialog through:
a click on the Edit this tool preset button
in the button bar of the Tool Presets Dialog.
a double-click on a preset icon in the Tool Presets Dialog .
a right-click on a preset in the Tool Presets Dialog to open a
context menu and then click on the Edit Tool
Preset command.
5.2.2. Using the Tool Preset Editor
You can edit presets you have created only; all options of predefined
presets are grayed out and disabled.
In this dialog you can :
edit preset name in text box,
change preset icon by clicking on
preset icon. This opens a window where you can choose a new icon.
select resources to be saved by
clicking on check boxes.
5. Misc. Dialogs 5.3. Device Status Dialog
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