| 摘要 |
PURPOSE: To prevent the increase of both calculation frequency and power consumption that are caused by the increase of a searching range by adaptively control the calculation frequency of evaluation value in accordance with the degee of inter-block movement. CONSTITUTION: The data to be coded are inputted to a block divider 11 via a coding frame memory 10. The divider 11 divides the image data equivalent to a single frame into pixels, and these pixels are inputted to a coding mode decider 100 and a motion vector detection part 200. If the decider 100 decides the validity of coding blocks, the block image data are inputted to a DCT 14 where the DCT coefficient is quantized by a quantizer 15. The quantized data undergo the adverse DCT as well as the adverse quantization via an adverse quantizer 16 and then written into a reference FM 30. At the part 200, a block matching unit 201 performs a differential operation between the coding blocks divided by the divider 11 and the reference block read out of the FM 30 in response to the instruction given from a sampling number indicator 203. Then a motion vector detector 202 detects the inter-block shift that has the least evaluation value within a searching range. |
