IMAGE PROCESSOR, IMAGE PROCESSING METHOD AND IMAGE PROCESSING PROGRAM

摘要

PROBLEM TO BE SOLVED: To prevent the edge of a block boundary part from being excessively smoothed in the case of removing block noise from an image decoded in each block of pixels. SOLUTION: The filtering of block boundary pixels is controlled on the basis of a wide area characteristic value indicating the degree of block noise in the whole decoded noise and a local value indicating the edge probability of the block boundary pixels. At the time of judging that no distortion exists in a target image from the wide area characteristic value, the whole processing is accelerated by completely omitting filtering. A wide area characteristic calculating function part 122 calculates the wide area characteristic value on the basis of a difference between a block boundary level difference and a level difference in the block or the like. A near-by characteristic calculating function part 123 detects edge probability by using the secondary differential value of intra-block pixels adjacent to the block boundary pixels. The edge probability can be detected also by double standard including the continuous edge strength of the block boundary pixels.