| 摘要 |
<P>PROBLEM TO BE SOLVED: To make feature amount processing insusceptible to alteration of a gray scale transformation table by providing a means for determining an appropriate feature amount extraction threshold. <P>SOLUTION: An image processing printer gamma section 409 performs gray scale transformation of image data based a printer gamma table. Multilevel image data subjected to gray scale transformation is quantized by error diffusion method employing an quantized threshold at a halftoning section 410. A feature amount extracting section 1701 extracts the feature amount of an image from image data subjected to gray scale transformation based on a feature amount threshold. Based on the feature amount subjected to feature amount extraction, a threshold selecting section 1702 selects one of a plurality of quantized thresholds, where at least the former of existence of periodic oscillation and the amplitude of oscillation is different, being employed for performing error diffusion method. The feature amount threshold being employed in extraction of feature amount is processed on the printer gamma table and the processed feature amount threshold is employed in extraction of feature amount. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
