| 摘要 |
PROBLEM TO BE SOLVED: To reduce the degree of narrowing dynamic range within the absolute minimum in order to cut off spike noises by obtaining the difference between a gradation maximum index and a gradation minimum index and using it for a range index. SOLUTION: A fixed length compression section encodes data in 128 bits, according to a prescribed compression system into 48-bit data consisting of an 8-bit range index LD denoting a density range in a block, of an 8-bit density index LA expressing a block density, and of a quantized pixel value in total in 32 bits, comprising each 2-bit obtained on the basis of the range index LD and the density index LA. This fixed length compression section obtains the gradation maximum index Qmax and the gradation minimum index Qmin. Thus, this image processor is reduced in the number of comparison processings and simplified in circuit configuration. Furthermore, the image processor obtains the mean value index LA and the gradation width index LD, on the basis of the gradation maximum index Qmax and the gradation minimum index Qmin. Thus, the dynamic range is prevented from being narrowed unnecessarily. |
