PAGE BACKGROUND ESTIMATION USING COLOR, TEXTURE AND EDGE FEATURES

An algorithm for estimating which pixels belong to the background of a scanned page. The algorithm is particularly designed to handle situations in which the page background varies in color/intensity, as is case when bleed-through artifacts from the reverse side of the page appear in the background. In determining background regions, including properly classifying bleed-through artifacts regions as such, the algorithm uses multiple local and global criteria for making the determination. In addition to being able to find large connected pieces of background, the algorithm is also able to find isolated islands of background by analyzing transition characteristics of neighboring regions. Regions are identified on the basis of similar local features and also by the nature of transitions between foreground regions that do not directly share a boundary. An adaptive white-point adjustment technique based on identified background regions improves the perceived quality of the printed output.