Sanner as a digital tool has been used widely.During the course of scanning, many distortions can be caused, at the same time noises is inevitably.

• 由于人为、印刷以及装订等原因,扫描图像不可避免地会含有各种各样的噪声,甚至产生几何畸变,这些都会影响对文本图像的识别效果和进一步的处理。