PICTURE ENCODING DEVICE

摘要

PURPOSE:To improve the compression efficiency and to reduce the degradation of the picture quality by determining the number of quantization bits of lower- order hierarchical data based on the quantization step width determined by higher-order hierarchical data having a low resolution with respect to each prescribed block of each hierarchical data. CONSTITUTION:Input picture data D31 are inputted to a difference circuit 41 and an averaging circuit 42. The circuit 42 generates a picture element X1(2) of second hierarchical data D32 from four picture elements X1(1) to X4(l) of input picture data D31 consisting of first hierarchical data as the lowestorder hierarchy. Picture elements X2(2) to X4(2) adjacent to the picture element X1(2) of data D32 are generated by the average of four picture elements of first hierarchical data D31 in the same manner. Data D32 are inputted to a difference circuit 43 and an averaging circuit 44, and the circuit 44 generates third hierarchical data D33 by the average of four picture elements of data D32. Data D33 are inputted to a difference circuit 45 and an averaging circuit 46. The circuit 46 generates fourth hierarchical data D34 consisting of picture elements X1(4) to X4(4) by the average of four picture elements of data D33. This method is repeated to generate first hierarchical encoded data D35.