Patent ID: 7292375

Claim:
A color image processing method comprising the steps of: edge-detection of a digital color original image obtained by digitally inputting only a single side of a document color-printed on both sides of paper; estimating background color of said paper or background color image on said single side based upon edge-detection information from the single side of the document with respect to a portion with low intensity of said detected edge from the single side of the document; performing color threshold processing in which said portion with the low edge intensity as a component corresponding to show-through of an image from an opposite side of the document is replaced with said estimated background color or background color image in said original image; and generating a show-through removed image as an image from which the component corresponding to the show-through has been removed from the original image without using the image from the opposite side of the document and without degradation of an image printed on the single side of the document.