GraphicsMagick is a robust collection of tools and libraries which support reading, writing, and manipulating an image in over 90 major formats including popular formats like DPX, DICOM, BMP, GIF, JPEG, JPEG-2000, PDF, PNG, PNM, SVG, and TIFF. A high-quality 2D renderer is included, which provides a subset of SVG capabilities. C, C++, Perl, Tcl, and Ruby are supported. Originally based on ImageMagick, GraphicsMagick focuses on performance, minimizing bugs, and providing stable APIs and ABIs. It runs on all modern variants of Unix, Windows, and Mac OS X.
Pixen is a sprite art program with many unique features. It is designed expressly for pixel art. To this end, it features extensive palette management and palette-swapping tools, a highly configurable grid overlay, a full complement of drawing tools, 'crosshairs' for ensuring proportion and straight lines, isometric line locking, extremely configurable backgrounds (for testing a sprite against various colors or images), and a full implementation of layers.
Seg3D is a volume editing and processing tool that combines a flexible manual segmentation interface with powerful higher-dimensional image processing and segmentation algorithms from the Insight Toolkit. DICOM, VFF, META, NRRD, and many other volume formats are supported. Users can explore and label image volumes using configurable, orthogonal slice view windows and 3D volume rendering.