ENCODING CIRCUIT FOR CONVERSION CODING OF IMAGE SIGNAL, DECODE CIRCUIT FOR DECODING THE SIGNAL, CODING METHOD AND DECODING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an encoding circuit and a decode circuit that can further reduce the bit rate. SOLUTION: In this coding circuit that converts an image signal into blocks each consisting of, e.g. 8×8 coefficients, each block having the coefficient is read adaptively to a motion. When a sub image has motion, the coefficient blocks are read in an order in which the sequence of the obtained coefficients have two interleaved sub sequences. Two interlaced sub fields are converted separately, the first sequence is started from a DC component and the second sequence begins with a DC coefficient. As a result, the coefficients are transmitted in the order of importance to the utmost. Thus, a mass with zero coefficients as large as possible is generated. Since the mass as above is transmitted by a small run length code, the bit rate with respect to a moving picture can be reduced effectively.