| 摘要 |
PROBLEM TO BE SOLVED: To provide a compression/extension processing system for providing the image of high picture quality at all the time even when image processing is performed to a decoded image extended by irreversibly compressing a source image while changing gamma γ. SOLUTION: The initial value of a compression parameter C2 corresponding to the set gamma γ is set to a compression part 11. Based on the compression parameter C2, the compression part 11 compresses source image data D0. A local extension part 13 prepares local decoded image data D4 extending compressed image data D1. A distortion calculating part 14 finds distortion DS of the local decoded image data D4. The compression parameter C2 is reset until the distortion DS is settled within a prescribed range. When the distortion DS is settled within the prescribed range, the compressed image data D1, extension method E1, information showing an extension parameter E2 and gamma γare preserved in a storage device 40. An extension means 20 extends the compressed data D1, and the extended decoded image data D2 and gamma γare inputted to an image processor 30. The image processor 30 performs image processing to the decoded image data D2 based on the gamma γ. |
