| 摘要 |
<p>PURPOSE:To shorten the recovery time of an image by writing the representative gradation value of a block on a memory by calculating in advance, and selecting the representative gradation value of the image to be processed out of written values. CONSTITUTION:All the representative gradation values are calculated in advance from La and Ld and are held at a representative gradation value calculation part 50 by remarking the fact that all the representative gradation values are represented by the La and the Ld. And the recovery of the image is performed by selecting the representative gradation value of a targeted image out of those representative gradation values from a representative gradation value selection part 50 according to a selection signal from a selection control part 70 generated by using resolution components phi1 and phi2 and a mode detecting signal. In such a way, time and labor to calculate the representative gradation value at every image element can be omitted, and the recovery time of the image can be shortened.</p> |
