BLOCK CODING SIGNAL DECODER

摘要

PURPOSE:To improve the picture quality by calculating part of a conversion coefficient resulting from applying orthogonal transformation to a block from information relating to picture element of part of the predicted block and applying inverse orthogonal transformation to the obtained conversion coefficient so as to predict and compensate the lost information of the entire picture elements in the block. CONSTITUTION:A block border periphery picture element prediction section 8 predicts some picture elements close to the border of blocks by using correlation or the like with surrounding block picture elements. The information relating to predicted picture elements 13 near the block border obtained in this way is converted in a form of an orthogonal conversion coefficient at an orthogonal transformation coefficient arithmetic section 9. The information relating to the obtained orthogonal transformation coefficient 14 is subjected to proper limit at a correction quantity control section 10, and the orthogonal transformation coefficient subjected to limit is subjected to inverse orthogonal transformation by an inverse orthogonal transformation section 11. The information 15 relating to the entire in-block correction value is related to a picture including block distortion being an output of the inverse orthogonal transformation section 7 at an output correction section 12. Thus, the output picture whose block distortion is reduced is obtained and then the picture quality is improved.