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.
PBM is a Portable image in black and white. Can be opened with programs: Adobe Photoshop CS, ACD Systems Canvas 15, ACD Systems ACDSee 17, Newera Graphics Converter Pro, Corel PaintShop Pro X6. File contains 1 bit per pixel. PBM is a kind of file format PPM. And can be readable or binary.