编程实现灰度图像的灰度值的统计，改变图像亮度分别使其整体变暗和变亮得到图像，显示原灰度图像、结果图像及其直方图。-Statistical programming grayscale image gray value, respectively, so that the overall change in image brightness dim and brighten get images showing the original gray-scale image, the resulting image and its histogram.