APPARATUS FOR CODING/DECODING IMAGE

摘要

The correlation between adjacent frames of a moving-picture signal is utilized to code and decode the signal while detecting the motion of each block of an image. There is provided a differential amplitude suppressing circuit which nonlinearly suppresses the amplitude of coded block data of an interframe difference based upon a threshold value for detection of motion. This circuit suppress the amplitude greatly when a detected value of motion is great in order to suppress the increase in the amount of coded data so that the reproduced moving image may be followed more faithfully. When the motion is small, the suppressing characteristics are reduced to improve the subjective quality of image. Further, the image signal sequence is integrated with time for each frame using a time integration circuit, the output of which is stored in a frame memory and read out at the same time. Therefore, the apparatus does not become bulky, and it is possible to eliminate the decrease in coding efficiency and the increase in generation of information by maintening reasonable delay time and proper interframe correlation.