Opencv 选取感兴趣区域 不在是指定的矩形 可以是任意图形！ 然后将选定的mask 放入到goodfeaturetotrack中实现任意区域的角点检测。-The Opencv select the area of ​ ​ interest is not in the specified rectangle can be any graphic! Selected and then the mask placed into goodfeaturetotrack corner detection