说明：  MATLAB的用户图像界面（GUI）（源码可见），可直接运行，依次为打开原图-三分图开输出alpha图，接着打开背景图可合成新图像
(MATLAB user graphical interface (GUI) (source visible), can be directly run, followed by open the original- plans to open three-point output alpha map, and then open a new background image can be synthesized)