This is a monochrome image format with a bitmap structure. It is used to store images of icons and cursors in the X Window System graphical user interface, which is used for remote connections. The structure of an XBM file consists of simple text written in the C programming language.
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.