COSINE TRANSFORMATION AND QUANTIZATION DEVICE, MULTIPLICATION OPERATION SAVING METHOD FOR IMAGE COMPRESSION DEVICE, INVERSE QUANTIZATION AND INVERSE COSINE TRANSFORMATION DEVICE AND MULTIPLICATION OPERATION SAVING METHOD FOR IMAGE DECOMPRESSION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a cosine transformation and quantization device used in an image compression device or the like with the small execution number of multiplication operations. SOLUTION: In order to save the multiplication operations of an image compression device, a prescribed primitive quantizer matrix is compensated by a scaling transformation coefficient led out from the sixth stage multiplication operation of a set of a discrete cosine transformation(DCT) speed calculation method and a corrected quantizer matrix is obtained. Then, the sixth stage internal multiplication operation of the DCT speed calculation method is omitted, a DCT unit 42 is constructed so as to perform the DCT to an input data block by the DCT speed calculation method and obtain transformed data through scaling transformation and a quantizer 22 is constructed so as to quantize the transformed data through the scaling transformation by the corrected quantizer matrix.