IMAGE DATA COMPRESSOR, IMAGE DATA EXPANDER AND DATA COMPANDER

摘要

PROBLEM TO BE SOLVED: To improve the compression rate of image data photographed by a stationary camera. SOLUTION: This compressor is provided with an input image memory 402 that stores an input image, a subtractor 403, a compression processing unit 404, and a reference image memory 407 that stores a reference image, and the image data stored in the input image memory 402 and in the reference image memory 407 are subtracted by the subtractor 403 and the subtracted data are compressed. Then a higher compression rate is obtained as an image with a smaller change from the reference image.