GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software suitable for such tasks as photo retouching, image composition and image authoring. 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, a image format converter, etc.
XPaint is an easy-to-use image editor which supports many standard and less standard paint procedures that demanding non-professional users would expect. It includes several advanced features like image processing algorithms, programmable C scripts, simultaneous editing of multiple images, and supports a wide variety of image formats.
SImg is a software for astronomical image processing. It contains a tool for visualization of highly dynamic images. The package consists of a library and applications which use it. Some of the features are deconvolution (various methods), Video4Linux support, PSF computation, approximation by linear combination of images and polynoms, various color transforms, automatic shifting of image sets (for addition and color composition), and more.
MultiSlice RTP is a radiotherapy treatment planning and medical image processing system developed for Silicon Graphics MIPS architecture systems and the IRIX operating system (5.3 and above). It allows you to manipulate upto 20 2D CT image slices as one 3D slice and run bulk batch processing algorithms on the images loaded. Written in C and linked against the MOTIF toolkit, it also runs on Xfree/Linux/Lesstif and can load RAW CT images from a CT scanner directly.
This is a set of brushes and patterns (other items may be added later) for use with the GIMP. Many of the brushes are converted from other formats that have been made available for use with other packages on different platforms. These data files are meant to compliment the Graphics Muse Tools plugins, but are not required by that package.
CinePaint is a deep paint image retouching tool that supports higher color fidelity than ordinary painting tools. CinePaint is used to retouch feature films and for professional photography. CinePaint opens high fidelity image file formats such as DPX, 16-bit TIFF, and OpenEXR, and conventional formats like JPEG and PNG. It has a flipbook for movie playback of image sequences in RAM. It supports 8-bit, 16-bit, and 32-bit color channels, HDR, and CMS.