Normalization of contrast in document images using generalized fuzzy operator with least square method

The visual effect of non-uniform contrast and brightness surrounds in the image is a very common problem in the applications of photocopying, IC manufacture and medicine. In using the digital/CCD camera to capture documents and photos based on non-uniform illumination condition, the poor image will be seen. The poor image can result in achieving the inaccurate reading from the optical character recognition (OCR) system. This paper presents a new approach to normalize the local contrast in documentation based on the least squares method and also enhance the object of interest using the generalized fuzzy operator (GFO). Two typical examples are used for evaluating the method.