直方图均衡方法的基本原理是：对在图像中像素个数多的灰度值（即对画面起主要作用的灰度值）进行展宽，而对像素个数少的灰度值（即对画面不起主要作用的灰度值）进行归并。从而达到清晰图像的目的。-Histogram equalization method of the basic principle is: the more the number of pixels in the image gray value (i.e., play a major role in the picture gray values) broadening, while the small number of pixels in the gray value (i.e., the picture not play a major role in gray value) to merge. So as to achieve the purpose of a clear image.