W.r.t. the steganography issue and image files (although I think sound files are probably more useful), Targa-24 images are RGB bytes (triples for each pixel, bottom-left to top-right), and seem appropriate for hiding a msg. They are also widely supported for conversion and function as a nice "device independant" image format (The Stone Soup Group's PicLab does a good job on them, IMHO). Does anyone know anything about YUV format? Also, DYUV or some other delta compressed format seems good. If a pixel changes by one more or one less than it "should" the image simply looks like a mediocre scan. Hmmm..... FLI is a delta format... is it appropriate? So... can someone whip up a utility to strip the PGP header and then perfoem some simple filtering (^= with some magic numbers, perhaps, or with some function of the preceeding bytes? Can this eventually help recover a better image, if that could ever be important? I don't think so) and tack on a valid Targa or other header (or correct any headers on images we've slid into). I just started a new job and am swamped, or I'd have written first and posted later ;-) . Seth morris <seth.morris@laUNChpad.unc.edu>