From the site: GWIC is a simple, fast and relatively efficient lossy image compression algorithm designed for compression of natural images. Currently both gray scale (8 12 and 16bpp) and RGB-images are supported, but in future support for alpha-channels is planned. GWIC is still in the middle of the designing phase, and thus should not yet be used in any real applications, since the file-format and algorithms are likely to change..

http://www.jole.fi/research/gwic/