COMPRESSION METHOD, EXPANSION METHOD, PARALLEL CONTEXT MODELLER, PARALLEL ENTROPY CODER, PARALLEL ENTROPY DECODER, PICTURE COMPRESSION DEVICE AND PICTURE EXPANSION DEVICE

摘要

PURPOSE: To provide a method and a device for efficiently compressing and expanding palletized pictures. CONSTITUTION: The pictures (B) are divided into color planes (C) and then compressed. So as to minimize the required number of pathes a coder and a decoder, the color planes are put into an order by density and the color plane of maximum density is coded first. The other color planes are coded after the first color plane is coded, however, the picture elements for which colors are recognized of the color plane coded first are not coded. The last color plane is not coded and estimated from all the other color planes. In decoding, the color planes are decoded in the same order.