Patent ID: 8179965

Claim:
A moving picture coding method for coding a moving picture by performing predictive coding with reference to a temporally preceding or following coded picture on a block-by-block basis, said method comprising: determining a luminance change, in which it is determined whether or not there is a possibility that a luminance change equal to or greater than a predetermined amount has occurred between the coded picture used for the reference and a current picture to be coded including a current block to be coded that is a block on which the predictive coding is performed; determining a flat region, in which it is determined whether or not a degree of non-uniformity in pixel values of pixels is smaller than a predetermined threshold, the pixels being included in the current block to be coded; and determining a quantization width used for quantization in coding the current block to be coded, wherein, in said determining the quantization width, when it has been determined (i) in said determining the luminance change, that there is the possibility that the luminance change equal to or greater than the predetermined amount has occurred, and (ii) in said determining the flat region, that the degree of non-uniformity is smaller than the predetermined threshold, a quantization width is determined to be a smaller value than a quantization width when it has not been determined: that there is the possibility that the luminance change equal to or greater than the predetermined amount has occurred; or that the degree of non-uniformity is smaller than the predetermined threshold.