数字识别系统的图像处理部分的源码，包括图像灰度转换，二值化，梯度锐化，去离散噪声，倾斜度调整，字符分割，归一化调整，紧锁重排等-Digital Identification System part of the source image processing, including image conversion, binarization, the gradient sharpening to discrete noise, tilt adjustment, character segment