This format was used for storing databases on the Pegasus and Palm PDA devices. Besides images, PDB allowed you to store tables, maps, e-books, and other data in a structured way. Today it has become obsolete and has been replaced by more flexible formats with DRM protection.
JP2 is a bitmap image format JPEG 2000. This can be a picture, an image from a surveillance camera, digital fax and other. In JPEG 2000 to compress the file using the technology of wavelet transform. This allows for a smoother and sharper image and the file size compared to JPEG for the same quality is lower.