Image processing system for reducing vertically disposed patterns on images produced by scanning

摘要

A digital image processing system applies an edge-based adaptive thresholding technique with different contrast parameters to convert an image into first and second binary images. In the digital processing system of the invention, the first and second binary images are compared and a map of the difference between the first and second binary images is generated. A vertical profile of this map is projected and local peaks in the vertical profile which correspond to a vertical pattern or artifact in the map is detected. Pixels in the first binary image are reversed based on the vertical pattern or artifact in the map. This system is effective in reducing vertical artifacts produced by scanners.