ImLab is a free open source graphical application for Scientific Image Processing that runs in Windows, Linux and many other UNIX systems. It supports multiple windows, data types including 32 bit integers, 32 bit real numbers and complex numbers.
Digital image processing programs for Windows and Linux systems.
tjsdigitalimage project provides a package containing a GUI-based image processing program called "Voyager" together with a collection of command-line image manipulation functions, suitable for use with very large images (longer than 4 GiB). Available in native 32 bit and native 64 bit versions for Intel 586/x64 and PPC/Cell on Windows and Linux.
PIAF (Prototype Image Applications Fast) is a prototyping tool for helping development of image processing algorithms. Based on a Qt GUI, it can display and process several live video inputs or still images with a plugins based architecture.