| 摘要 |
PROBLEM TO BE SOLVED: To remarkably reduce the amount of codes while minimizing image degradation by outputting only a 1st index value showing a gradation level to be expressed as a while block as a code when the dispersion of image data in the block is a little. SOLUTION: An encoder part 202 encodes image data to obtain a 1st index value La, a 2nd index value Ld and a quantified data Φij. A compactor part 207 compares the 2nd index value Ld with a threshold value th of a threshold value latch circuit 206 to output '1' as a compared result bit when the 2nd index value is higher than the threshold value th, and to output '0' when it is lower than the threshold value th. When the compared result but is '1' in a selector 211, the 1st index value La, the 2nd index value Ld and the quantized data Φij are read out of 4th-6th latch circuits 208-3210 in this order, and in the case of '0', only the 1st index value La is read out from the 4th latch circuit 208. |
