希望显示的结果是四张图，第一张是原始图像

第二张是两张合成对比，上半部分是灰度图像，下半部分是中值滤波后的图像

第三张是两张合成对比，上半部分是灰度直方图，下半部分是均衡直方图

第四张式均衡化的图像。

-Want to show the results of the four Figure, the first is the original image is two synthetic contrast, the upper part of the gray-scale image, the lower half of the image after median filtering the two synthetic contrast The upper part of the histogram, the lower half of the fourth-balanced histogram equalization image.