| 摘要 |
<p>PURPOSE:To code an important image area in a less distortion state by changing the value of distortion in each block in accordance with each area. CONSTITUTION:A distortion changing part 9 sets up only distortion data 8 relating to an important image area to a value larger than a practical value as distortion data 10 and an allowable distortion detecting part 14 finds out allowable distortion 11 for compressing data to data volume specified by a compression ratio 15 from the distortion data 10 of one image. An unequal length block dividing part 4 compares the distortion data 10 of all blocks with the allowable distortion 11, and selects coefficient data 3 relating to the block having distortion less than the value of the allowable distortion 11 and the maximum size to use as coefficient data 5. A quantizing part 12 quantizes the coefficient data to use as coded data 13. Consequently, the important image area can be coded in the less distortion state without adding excess information to the coded data 13.</p> |
