Intelligence thresholding for degraded text-photo document images

The conversion of the content from paper books into digital form is captured by digital cameras or scanners. However, after the conversion, the illumination of the captured document images is often unevenly distributed. Conventional thresholding methods cannot threshold these kind documents, usually full text images, properly. If the degraded document image includes both text and photo, these methods produce unsatisfactory binarizaion results. This paper presents an efficient and effective intelligent thresholding method for degraded text-photo document images, including: gray-level region cutting is proposed to segment the gray-level document image into several regions intelligently; each region is thresholded by using region thresholding; the gray-level document image is converted into a binary image. Experimental results show that the performance of the proposed method is better than other available thresholding methods in visual measurement.