Image processing device for correcting gradation of color image

摘要

This invention provides an image processing device in which a pixel satisfying a certain unwanted gradation condition with respect to all the plurality of color components is judged as a unwanted pixel derived from unnecessary image data, and each of gradation data of the plurality of color components composing the unwanted pixel is converted into a certain background gradation which is predetermined with respect to each one of the color components. The image processing device eliminates a possibility that a pixel satisfying the unwanted gradation condition with respect to part of the color components is judged as the unwanted pixel. This arrangement enables to securely extract and remove the unwanted pixel attributed to the unnecessary image data such as undertone and backside image data and prevents degraded image reproduction due to color change resulting from erroneous removal of part of the color components of the necessary image data.