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.
WBMP is a bitmaps wireless application protocol. Files with the extension .wbmp contain bitmap black and white images. In WBMP format monochrome images are in pixels. Pixels are presented in the form of units, are stored as white and pixels, represented as pairs are stored as black. WBMP images are used in a variety of mobile phones.