METHOD FOR COMPRESSING PICTURE AND ITS DEVICE

摘要

PROBLEM TO BE SOLVED: To enhance a compression rate without deteriorating picture quality in picture compression by adopting a quantization coefficient in a screen area with less movement vector quantity change as zero. SOLUTION: Difference data between pre-picture data obtained by a restoring processing and picture data (present picture data) of a succeeding screen divided into plural screen areas and movement vector quantity for making difference data to be min. are extracted as movement compensation and also movement vector quantity is stored. Then, before the quantization coefficient is variable length-encoded, stored movement vector quantity is compared with obtained movement vector quantity so as to judge whether or not the change quantity of movement vector quantity is less than a prescribed value. When it is less than the prescribed value, the corresponding quantization coefficient is made to be zero and also movement vector quantity is updated to be the latest value.