Mat bg = Mat::zeros(Size(512, 512), CV_8UC3); Point p1(100, 100); Point p2(350, 100); Point p3(450, 280); Point p4(320, 450); Point p5(80, 400); std::vector<Point> pts; pts.push_back(p1); pts.push_back(p2); pts.push_back(p3); pts.push_back(p4); pts.push_back(p5); polylines(bg, pts, true, Scalar(0, 0, 255), 2, 8, 0); fillPoly(bg, pts, Scalar(0, 255, 255),8, 0); std::vector<std::vector<Point>> contours; contours.push_back(pts); drawContours(bg, contours, -1, Scalar(255, 0, 255), 2); imshow("Draw_polygon", bg);