PARALLEL DIFFERENCE CODING METHOD FOR LOSSLESS COMPRESSION AND REAL TIME DECOMPRESSION

A block based hybrid compression method where the input page is classified as SOLID, TEXT, SATURATED TEXT or IMAGE type, and the compression method most appropriate for each class is chosen on a block by block basis. Blocks classified as IMAGE may be compressed using Parallel Differential Pulse Code Modulation. This method allows the decompression algorithm to decode multiple pixels in parallel, thus making real time decompression significantly easier to implement. The methods shown will execute very efficiently on a Texas Instruments TMS302C82 multiprocessing Digital Signal Processor.