| 摘要 |
<p>First density histogram generation means (8A) generates a first density histogram based on a first image signal which is obtained by reading a data read region. Of peak portions formed in the first density histogram, the density rank value of a peak portion which satisfies a predetermined condition is detected. Pixel-to-be-removed detection means (8C) determines pixels-to-be-removed whose average densities are included in a pixel removal density range which corresponds to said detected peak portion density rank value. Regarding all pixels without said pixels-to-be-removed, a second density histogram is generated. Based on the second density histogram, cumulative density histogram is generated to thereby find a highlight point and a shadow point through which a gradation curve must passes. Then, the gradation curve is established, in accordance with which an image processing part (3) converts the first image signal into a second image signal. <IMAGE></p> |
