METHOD AND APPARATUS FOR COMPRESSING IMAGE SIGNAL

摘要

A method of compressing image signals, to provide more efficient compression than a discrete cosine transform (DCT) while having the least amount of overhead information is provided. A partial exchange between a row and a column of a transform matrix is performed by applying several values to a parameter, which shows an extent of partial exchange between rows and columns of the transform matrix. When a value of the used angle parameter is stored or transmitted, an overhead increases. Processes generating a random sequence of the angle parameter, generating a compression coefficient matrix regarding each angle parameter of the generated random sequence, and calculating a compression rate are repeated to obtain an angle parameter with the highest compression rate. The angle parameter having the highest compression rate is not stored or transmitted, but a number in the random sequence of the corresponding angle parameter is obtained, and stored or transmitted.