| 摘要 |
<p>PROBLEM TO BE SOLVED: To save power consumption while suppressing image quality degradation. SOLUTION: An input picture 1a from an input terminal 1 is fed to a motion vector rough retrieval circuit 16 and a motion vector fine retrieval circuit 17, where a motion vector is retrieved for every input picture. A system control circuit 18 decides whether an input picture is of a still picture type S, a quasi- still picture type T or a moving picture type M on the basis of motion information 16b denoting a count result of motion vectors retrieved by the motion vector rough retrieval circuit 16 and a code residual quantity 11b denoting a residual code quantity by a variable length coding circuit 11, and in the case of the type S or T, the motion vector rough retrieval circuit 16 is deenergized and in the case of the type M, the motion vector rough retrieval circuit 16 is activated. Furthermore, the system control circuit 18 activates the motion vector rough retrieval circuit 16 when the motion vector rough retrieval circuit 16 is inactive and the decision information from a coding image decision circuit 4 indicates a picture of the moving picture type M.</p> |
