在对图像进行处理之前，了解图像整体或局部的灰度分布情况非常必要。对图像的灰度分布进行分析的重要手段就是建立图像的灰度直方图，利用图像灰度直方图，可以直观地看出图像中的像素亮度分布情况；通过直方图均衡化、匹配（规定化）等处理，可以对图像的质量进行调整。该段代码就是对直方图的各种处理，如，直方图生成直方图均衡化和直方图匹配。

-In the image before treatment, understand the whole or local image of gray distribution is very necessary. The image of gray distribution was analyzed the important means of image is the establishment of gray histogram, use of gray histogram image, that can be directly in the images of the pixel luminance distribution　Through histogram equalization, matching (the regulations) processing, the quality of the image can be adjusted. When the code is to the histogram of processing, such as, histogram generation histogram equalization and histogram match.