opencv-2-circle line etc.

#include "stdafx.h"
 
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/opencv.hpp>


using namespace cv;
using namespace std;
int main(void) {

Mat img = imread("../lena.jpg", 1);

        line(img, Point(100, 100), Point(300, 300), CV_RGB(0, 255, 0), 3);

//circle(img, Point(300, 300),50, CV_RGB(0, 255, 0), 3);

        //rectangle(img, Point(100, 100), Point(300, 400), CV_RGB(0, 255, 0), 3);

        //string words = "lena";
//putText(img, words, Point(img.rows / 2, img.cols / 4), CV_FONT_HERSHEY_COMPLEX, 1, Scalar(0,255, 0));

imshow("test", img);
waitKey(0);
 
return(0);
}