/** @brief Draws a line segment connecting two points.*/

CV_EXPORTS_W void line(InputOutputArray img, Point pt1, Point pt2, const Scalar& color,

                     int thickness = , int lineType = LINE_8, int shift = );

                  int thickness=, int line_type=, int shift=, double tipLength=0.1);

/** @brief Draws a simple, thick, or filled up-right rectangle.*/

CV_EXPORTS_W void rectangle(InputOutputArray img, Point pt1, Point pt2,

                          const Scalar& color, int thickness = ,

                          int lineType = LINE_8, int shift = );

/** @brief Draws a simple or filled circle with a given center and radius.*/

CV_EXPORTS_W void circle(InputOutputArray img, Point center, int radius,

                       const Scalar& color, int thickness = ,

                       int lineType = LINE_8, int shift = );

/** @brief Draws a simple or thick elliptic arc or fills an ellipse sector.*/

CV_EXPORTS_W void ellipse(InputOutputArray img, Point center, Size axes,

                        double angle, double startAngle, double endAngle,

                        const Scalar& color, int thickness = ,

                        int lineType = LINE_8, int shift = );

/** @brief Fills the area bounded by one or more polygons. */

CV_EXPORTS_W void fillPoly(InputOutputArray img, InputArrayOfArrays pts,

                           const Scalar& color, int lineType = LINE_8, int shift = ,

                           Point offset = Point() );

/** @brief Draws a text string.*/

CV_EXPORTS_W void putText( InputOutputArray img, const String& text, Point org,

                         int fontFace, double fontScale, Scalar color,

                         int thickness = , int lineType = LINE_8,

                         bool bottomLeftOrigin = false );

#include <opencv2/opencv.hpp>

#include <iostream>

#include <ctype.h>

using namespace std;

using namespace cv;

void DrawLine(Mat img, Point start, Point end)

{

    int thickness = ;

    int lineType = ;

    line(img, start, end, Scalar(, , ), thickness, lineType);

}

void DrawEllipse(Mat img, double angle)

{

    int thickness = ;

    int lineType = ;

    ellipse(img,

        Point(img.rows / 2.0, img.cols / 2.0),

        Size(img.rows / 4.0, img.cols / 16.0),

        angle,

        ,

        ,

        Scalar(, , ),

        thickness,

        lineType);

}

void DrawFilledCircle(Mat img, Point center)

{

    int thickness = -;

    int lineType = ;

    circle(img,

        center,

        img.rows / 32.0,

        Scalar(, , ),

        thickness,

        lineType);

}

void DrawRect(Mat img, Point start, Point end)

{

    rectangle(img, start, end, Scalar(, , ), );

}

int main() {

    CvFont font;

    Mat m = Mat::zeros(, , CV_8UC3);

    m.setTo(cv::Scalar(, 10, ));

    DrawEllipse(m, );

    DrawEllipse(m, );

    DrawEllipse(m, );

    DrawEllipse(m, -);

    DrawFilledCircle(m, Point(m.rows / , m.cols / ));

    DrawRect(m,Point(m.rows/,m.cols/),Point(m.rows/+m.rows/, m.cols/+ m.cols/));

    cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 1.0, 1.0, , , );

    IplImage* image = &IplImage(m); // Mat -> IplImage 类型转换

    cvPutText(image, "Hello World !", cvPoint(, ), &font, cvScalar(, , , ));

    imshow("椭圆图", m);

    waitKey();

}

cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 1.0, 1.0, , , );

IplImage* image = &IplImage(m); // Mat -> IplImage 类型转换

cvPutText(image, "Hello World !", cvPoint(, ), &font, cvScalar(, , , ));

imshow("椭圆图", m);