This format is used for storing bitmap images. It supports many different file types and compression algorithms. One Palm bitmap file can contain multiple versions of the same images with different colors. These files are used on PALM devices.
A bitmap image in the Portable Any Map format that was originally developed for processing and storing several types of monochrome and color images without compression as well as grayscale images. Bitmap graphics data in a PNM file are stored using ASCII or binary structure.