| 摘要 |
PROBLEM TO BE SOLVED: To remove an unnecessary image part such as a ground color and a see-through image from a color input image while suppressing the degradation of the image and to ease a difference in levels of gradation to be generated by removing the unnecessary image part. SOLUTION: A gradation range of the unnecessary image part is found out in each color component from gradation data of all pixels of the input image and a removing gradation condition is set up in each color component on the basis of the gradation range. A pixel satisfying the removing gradation condition in all of the color components is decided as the pixel to be removed out of al the pixels of the input image and the gradation of the pixel to be removed out is converted into '0' and removed out. The pixel belonging to the gradation range near to the unnecessary image part is decided as the pixel to be adjusted, a prescribed common gradation reduction ratio for respective pixels to be adjusted is found out and the gradation of all color components of each pixel to be adjusted is converted on the basis of the common gradation reduction ratio. |
