One method the guy left out is XWPICK. You have to do a search for it. But the programs are out there and it works on 8 bit pseudo color screens and windows.
XV (RPM)ÿ can be downloaded from here. Its even available for Windows systems, but you must have an X window system running. Such as Hummingbird Xceed.ÿ You can get this for SGI's also.ÿ
GIMP is a full featured image manipulation program. It is better than that Adobe stuff too, free and open source. You can't beat it. It just happens to have a screen dump facility. Gimp Links. Here you can find GIMP documentation.
GTK+ is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off projects to complete application suites.
There are all sorts of tricks you can do with Image Magick a few are listed here in an article in LINUX Focus magazine. Some of the tricks you can do are quite amazing too. The gentle introduction and a real good tutorial are here. Command line Image manipulations can also be done, see here for examples, you can also find some stuff here.
TIFF is an extremely common but quite complex raster image format. LibTiff is a standard implementation of the TIFF specification that is free and works on many operating systems.ÿ