线段:line 函数
CV_EXPORTS_W void line(CV_IN_OUT Mat& img, Point pt1, Point pt2, const Scalar& color, int thickness=1, int lineT ype=8, int shift=0);CV_EXPORTS_W void line(CV_IN_OUT MCV_EXPORTS_W void line(CV_IN_OUT Mat& img, Point pt1, Point pt2, const Scalar& color, int thickness=1, int lineT ype=8, int shift=0);CV_EXPORTS_W void line(CV_IN_OUT M