| 摘要 |
PROBLEM TO BE SOLVED: To apply compression processing to data such as image information and audio information that are prediction-coded at a high compression rate and at a high speed. SOLUTION: A pixel block division means divides a received image block of N×M pixels with a luminance Y into blocks each consisting of 2×4 pixels that are sufficiently smaller than the N×M pixels. A macro bit map information recording means obtains an average luminance Yav in the block of 2×4 pixels and divides the block into a group GY1 whose luminance is higher than the Yav and a group GY2 whose luminance is lower than the Yav and records the position of the groups GY1 , GY2 in the block as bit map information in 2×4 bits. A block coding means obtains average luminance Y1 of the group GY1 and average luminance Y2 of the group GY2 respectively and uses the Y1 , Y2 , block bit, map information(BBM). Furthermore, an entropy coding processing means reduces redundant information in the block, in the frame and inter-frame respectively. Other information is compressed by using the adaptive Huffman coding method or the adaptive arithmetic coding method. |
