直方图均衡化通过有效地扩展常用的亮度来实现这种功能。尤其是当图像的有用数据的对比度相当接近的时候-Histogram equalization, to effectively extend the brightness of the commonly used to achieve this functionality. Especially is when the the the alerts of the the contrast of the of the the of useful data of the image which are quite close