图像处理源程序，实现二值化变换，经一幅图像灰度化后，变成二值化图像，包括大津法、最大类间方差法、一般阈值法、及文本识别最有用的Niblack法-Image processing program and realized binarization transformation, after by a gray-scale image into binary image, including the Otsu method, Otsu method, the general threshold, a