This file format is used to transmit image data. It contains a set of images that can be linked to form an animation. It is used to store non-compressed bitmap images in 24-bit color created using MTV ray tracer.
PGM is a storage format for grayscale images. Files in this format can be opened using software: ACDSee Photo Manager 14, ACD Systems Canvas 15, Corel PaintShop Pro X4. This type of file can be edited with a text editor. PGM files can be in two versions: P2 / P5. P2 are readable, P5 - to binary formats.