说明：  求取一幅二值图像包含目标区域的最小矩形框，返回矩形框的上下左右边界，然后根据边界坐标在图上画出目标区域。
(Strike the rectangle that contains the smallest rectangular target area in a binary image, return to the top and bottom rectangular box around the border, and then draw the boundary on the map coordinates of the target area.)