用c#做的，类似QQ的屏幕截取工具 方便好用-Use c# to do a screen similar to the interception of QQ easy-to-use tool

利用Hough transform计算图片中两条直线间的角度，同时计算图片中所有直线汇聚于某一点的坐标-Find the angle of these tow lines shown in the image by Hough transform.As you can see in the image all of such lines are going to merge to a special point (perspective