is a format developed by Sony for its proprietary Sony Reader devices. Files in this format may contain text and images. The format is XML-based.
BMP is format for storing bitmap images. In this format, you can only save bitmaps monolayer. For each pixel in different files may come different number of bits. The latest versions of the BMP has the ability to control color. In particular, you can specify the endpoints perform gamma correction and embed color profiles ICC.