PICTURE DECODER

PURPOSE:To provide the picture decoder decreasing block distortion, generating a preferred sharp edge component in the inside of a block so as to obtain a decoded picture. CONSTITUTION:A picture fetched from an input device 1 is divided into blocks of a prescribed size by a coder 2, orthogonal transformation for each block is implemented, a high frequency component is eliminated and the result is coded. A decoder 100 decreases block distortion of the coded picture and simultaneously decodes the picture while reducing a fog of the picture such as unsharpened edge in the inside of the block and the picture is outputted from an output device 21. The picture coded by the method being the combination of block coding and orthogonal transformation is subject to block distortion elimination at a block border and production of preferred sharp edge component in the inside of the block and the result is decoded by the picture decoder.