Adaptive dynamic range encoding method and apparatus

摘要

An adaptive dynamic range encoding method and device in which evaluation data mainly centered about the amount of the change in the spatial direction of picture data in a block is detected, and re-quantization is performed which will give a minimum value of the evaluation data. The re-quantization is performed at an optimum quantization step conforming to the picture in the block in such a manner that picture portions having the same level may remain at the same level after re-quantization. This renders it possible to eliminate quantization distortions from being produced in the reproduced picture.