IMAGE DATA PROCESSOR AND ITS METHOD

摘要

PROBLEM TO BE SOLVED: To obtain an image data processor capable of obtaining a high compression ratio by predicting the significant space of high frequency sub-bands from low frequency sub-bands in wavelet space and masking data other than data in the predicted significant space. SOLUTION: At the time of receiving image data 151, a 1st stage two- dimensional(2D) sub-band divider 102a generates respective sub-band signals 153 to 156 of a layer 0. At the time of receiving an LL sub-band signal 153, a subtracter 109 generates a differential LL sub-band signal 157 expressing a difference between the signal 153 and the LL sub-band signal of the layer 0 corresponding to the frame just before decoder reproduction. Then respective sub-band signals 158 to 165 of layers 1, 2 are generated. At the time of receiving sub-band signals 154 to 165 other than the LL sub-bands of respective layers, a zero value predicting compressor 103 generates the zero area predicting sub- band signals 166 to 177 of respective layers. At the time of receiving respective sub-band signals 162 to 165 of the layer 2 and the generated sub-band signals 166 to 171, a VLC device 104 generates a compression signal 152.