Graphics Tools


ImageMagick
Powerful interactive image manipulation, viewing and animation tool. Will convert, resize, thumbnail, create transparent, create composite & much more

GNU Image Manipulation Program
The GIMP, styled loosely after Adobe Photoshop,  can  be used for photo retouching, image composition and image authoring

XV
This shareware image viewer/manipulator has an excellent user interface and image enhancing algorithms. Widely used and respected tool.