A method of multithresholding a document image considers both local and global information in determining the number of thresholded levels contained in a gray-scale image. A gray-scale image is comprised of a plurality of pixels. Each pixel has an intensity value. Local regions of pixels...http://www.google.fr/patents/US5781658?utm_source=gb-gplus-shareBrevet US5781658 - Method of thresholding document images
