A Free Experimental System for Image Processing
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. It is implemented in C++ and also in C to provide a very simple way to add new functions. It has many image operations and supports several file formats.
Download: ImLab 2.3.1