| 摘要 |
PURPOSE:To improve the compression efficiency at the time of transmission of picture data and to reduce the degradation of the picture quality by adaptively switching the quantization decoded value of each hierarchy in accordance with the quantization characteristic in each hierarchy for encoding of hierarchical encoded data. CONSTITUTION:First to fifth hierarchical compressed and encoded data D51 to D55 are decoded by a picture decoding device 60. That is, these data D51 to D55 are inputted to decoders 61 to 65 having the encoding technique opposite to that of encoders, and decoded inter-hierarchy difference data D56 to D59 of first to fourth hierarchies are inputted to first to fourth adding circuits 66 to 69. Data D55 are decoded by the decoder 65, and fifth obtained hierarchical data D60 are inputted as it is, and data D60 are added to data D59 by the adding circuit 69 to restore fourth hierarchical data D64, and this data D64 are sent to the adding circuit 68. First to fifth hierarchical data D61 to D65 are outputted in the same manner. Decoders 61 to 64 properly change decoded values of quantization values, which are generated by decoders, in accordance with conditions. |
