DEVICE FOR CODING AND DECODING PICTURE SIGNAL

摘要

In the conventional transformation coding of pictures the value ranges of the coefficients then produced are extended during the performance of the individual arithmetical steps. As a result thereof these coefficients have a great redundancy. According to the invention, the arithmetical steps which are formed by the basic transformation of two values are performed so that as a result of each arithmetical step only the original word length is obtained, because in each arithmetical step a portion of the value range of the result is mapped onto a different area. An example for the technical implementation of such a mapping on modified coefficients and the retransformation of these modified coefficients is described.