摘要 |
A coded picture signal re-quantization system, in which a parameter such as a variance or a mean value of picture element values in a region to be re-quantized is calculated on the basis of sub-sampled picture element values and, according to this parameter, a quantizer is adaptively varied for each region and, further, quantization of thinned-out picture elements is performed or stopped as required, thereby effecting conditional re-quantization. |