View source for GIMP

The GNU Image Manipulation Tool is a free, powerful, bewildering image editing suite. It is in many ways similar to Adobe Photoshop. The [http://www.gimp.org GIMP homepage] has a great many tutorials.

==Batch mode==
GIMP can be driven from the command line using the -b (batch mode) option, together with Scheme scripts. The GIMP webpage has a [http://www.gimp.org/tutorials/Basic_Batch/ tutorial]. The Procedure Browser (Xtns menu in the Toolbox) provides a detailed list of all identifiers. Scripts are loaded from a script directory specified in Edit->Preferences->Folders->Scripts.

==Recipes==
===Rounding corners===
The [http://docs.gimp.org/en/script-fu-round-corners.html Round Corners filter] can round the corners of rectangular images. Rounding more complicated shapes can be accomplished using [http://www.novell.com/coolsolutions/feature/11583.html shrinks]. It's wise to then feather your selection (right click, Select, Feather) for a softer boundary; note that <tt>script-fu-round-corners</tt> doesn't appear to do this.
===Filmstrip===
Open multiple images as layers within one image, and apply the Combining->Filmstrip filter.
===[http://www.itnewb.com/tutorial/Optimize-Your-Web-Site-by-Using-CSS-Image-Sprites CSS Sprites]===
The [http://registry.gimp.org/node/25908 CSS WebSprite] plugin can handle css sprite generation from opening several images as layers.