A Quickly Skew Correction Algorithm of Bill Image

In automatic document image processing system, skew correction and black margin removal are important principal steps. In this paper, a new algorithm of quickly skew correction is proposed. Based on characteristics of bill images, the positions of four corners were obtained and the slant angle is calculated. Using the slant angle to rotate bill image and removal black margin, the needed bill image can be obtained. Experiments show that our methods can reduce black margin noise well and can detect the slanting angle of an image rapidly and accurately.