简单的图像处理程序，实现了如图想的灰度直方图，取反，线性变换，灰度拉伸等功能，无错，可以运行，适合初学者参考学习。-Simple image processing program, realized the figure to the gray-level histogram, invert, linear transformation, gray stretch, and other functions, there is no wrong, you can run, suitable for