| 摘要 |
<p>PURPOSE:To enhance compressibility in the case a variation is small, to improve the average compressibility, and also, to eliminate an isolated block by determining encoding by variation information to an adjacent block, and to prevent flickering by executing encoding only in the case a variation of the previous image and the present image is recognized. CONSTITUTION:The present image data is compared with the previous image of a buffer 12 and a variation is calculated by a variation calculating part 13, compared with a threshold of a threshold holding part 14a by a variation deciding part 14 and whether it is an effective block or not is decided. In the case it is an effective block, it is added to a holding part of a variation information updating part 15, and updates an address. This variation information is outputted through a multiplexer 17, and also, a buffer 11 sends data of the effective block to an ADCT encoding part 16 and encodes it, and moreover, updates the block of the previous image of the buffer 12. In such a way, by improving compressibility in the case a variation between images is small, average compressibility is enhanced, and also, encoding of the block is determined by rewritten variation information, an isolated block is eliminated and flickering is prevented.</p> |
