| 摘要 |
PURPOSE:To improve subjective picture quality, by finding the contrast of each block after dividing an input image into plural blocks in advance and performing encoding after classifying the image to plural types at every block at an encoding side, and performing decoding by using a parameter suitable for each type at a decoding side. CONSTITUTION:A contrast detector 1 defines contrast Ci(j, k) on a picture signal Fi(j, k) inputted at (i)th order, and adds it on an image feature parameter encoder 5 and a picture signal parameter setting apparatus 17. The image feature parameter encoder 5 performs unequal length encoding on the Ci(j, k), a Gi(j, k), and an area signal Bi(j, k) by a Hofmann encoding or a runlength encoding, etc., and adds them on a multiplexer 18, and outputs them to a transmission path 8, An image decoder 20 performs an operation corresponding to an image encoder 16 according to a defined encoding parameter, and decodes an encoded picture signal, and outputs it to an output terminal 101. In such a way, no encoding distortion such as block distrotion can be shown prominently, and the image can be encoded in superior picture quality. |
