This program creates a rectangle when you click the mouse on the window, and stretches the rectangle until you release the mouse. This requires the creation of a mouse callback. For the main function we use a while loop that keeps redrawing each box

基于opencv1.0的鼠标事件响应，相当好用，本人极力推荐，就是解释是日语-Based opencv1.0 mouse incident response, very easy to use, I strongly recommend that interpretation is in Japanese