| 摘要 |
PROBLEM TO BE SOLVED: To provide a dynamic image decoding method, which is suitable for obtaining a reproduced image having its resolution lower than that of an original image and also is capable of reducing computational complexity, by lowering the accuracy of inverse DCT (spatial compression) set with respect to a luminance (Y) signal, in comparison with the accuracy of the inverse DCT set with respect to a color difference (C) signal. SOLUTION: At a C-zero permutation processing part 5 of an MPEG decoder, the DCT coefficients of areas having horizontal frequency of 4 or more are permutated to 0 from among the DCT coefficients of each (8×8) micro-block. At a Y-zero permutation processing part 4, the DCT coefficients of areas having horizontal and vertical frequencies of 4 or more are permutated to 0 from among those DCT coefficients of every (8×8) sub-block. In other words, some of DCT coefficients are permutated to 0, so as to set the inverse DCT accuracy set to the DCT coefficient of a color difference (C) signal at a level higher than the inverse DCT accuracy set with respect to a DCT coefficient of a luminance (Y) signal. |
