2002.02.01 01:20 "tiff (libtiff)", by spin soft
2002.02.01 16:03 "Re: tiff (libtiff)", by Leonard Rosenthol
For Unixen I'd recommend ImageMagick (http://www.imagemagick.org/); or you could do it with the Gimp (http://www.gimp.org/) if you prefer point&click to command-line tools.
Dunno what's available for Windows or Mac.
ImageMagick runs just fine on Windows and Mac OS as well...For Windows, we even include our own GUI for the "point and click" crowd ;).
Leonard