The PPM which is an acronym for Portable Pix-Map is a simple structured RGB raster image format. It is actually part of Netpbm, an open-source package of graphics programs used in Unix operating systems.
Because of its simple and general design, it's easy to develop programs to convert, manipulate and create the image. The file contents could be either ASCII or binary defined in its simple always ASCII header information.
|Easily exchange binary images between platforms back in the '80s.
|Jeffrey A. Poskanzer