OpenCV 基本图形绘制函数详解

• 用于绘制直线的line函数；

• 用于绘制椭圆的ellipse函数；

• 用于绘制矩形的rectangle函数；

• 用于绘制圆的circle函数；

• 用于绘制填充的多边形的fillPoly函数。

#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

using namespace cv;
using namespace std;

#define WINDOW_WIDTH 600 // 定义窗口大小的宏
#define WINDOW_NAME1 "原子图"        //为窗口标题定义的宏
#define WINDOW_NAME2 "多边形图以及画线"        //为窗口标题定义的宏

/***绘制椭圆***/
void DrawEllipse(Mat img, double angle)
{
   int thickness = 2; //  线宽
   int lineType = 8; // 线性，8 代表联通线性

ellipse(img,
       Point(WINDOW_WIDTH / 2, WINDOW_WIDTH / 2),
       Size(WINDOW_WIDTH / 4, WINDOW_WIDTH / 16),
       angle, // 角度，0~360 度
       0,
       360,
       Scalar(255, 129, 0),
       thickness,
       lineType);
}

/*绘制实心圆*/
void DrawFilledCircle(Mat img, Point center)
   int thickness = -1; //  线粗-1，代表实心

circle(img,
       center,
       WINDOW_WIDTH / 32,
       Scalar(0, 0, 255),

/*凹多边形绘制*/
void DrawPolygon(Mat img)
   int lineType = 8;

// 创建一些点
   Point rookPoints[1][20];
   rookPoints[0][0] = Point(WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8);
   rookPoints[0][1] = Point(3 * WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8);
   rookPoints[0][2] = Point(3 * WINDOW_WIDTH / 4, 13 * WINDOW_WIDTH / 16);
   rookPoints[0][3] = Point(11 * WINDOW_WIDTH / 16, 13 * WINDOW_WIDTH / 16);
   rookPoints[0][4] = Point(19 * WINDOW_WIDTH / 32, 3 * WINDOW_WIDTH / 8);
   rookPoints[0][5] = Point(3 * WINDOW_WIDTH / 4, 3 * WINDOW_WIDTH / 8);
   rookPoints[0][6] = Point(3 * WINDOW_WIDTH / 4, WINDOW_WIDTH / 8);
   rookPoints[0][7] = Point(26 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
   rookPoints[0][8] = Point(26 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
   rookPoints[0][9] = Point(22 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
   rookPoints[0][10] = Point(22 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
   rookPoints[0][11] = Point(18 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
   rookPoints[0][12] = Point(18 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
   rookPoints[0][13] = Point(14 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
   rookPoints[0][14] = Point(14 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
   rookPoints[0][15] = Point(WINDOW_WIDTH / 4, WINDOW_WIDTH / 8);
   rookPoints[0][16] = Point(WINDOW_WIDTH / 4, 3 * WINDOW_WIDTH / 8);
   rookPoints[0][17] = Point(13 * WINDOW_WIDTH / 32, 3 * WINDOW_WIDTH / 8);
   rookPoints[0][18] = Point(5 * WINDOW_WIDTH / 16, 13 * WINDOW_WIDTH / 16);
   rookPoints[0][19] = Point(WINDOW_WIDTH / 4, 13 * WINDOW_WIDTH / 16);

const Point* ppt[1] = { rookPoints[0] }; // 多边形定点集
   int npt[] = { 20 }; // 多边形定点数目

fillPoly(img,
       ppt,
       npt,
       1,
       Scalar(255, 255, 255),  // 多边形颜色：白色

/*线绘制*/
void DrawLine(Mat img, Point start, Point end)
   int thickness = 2;
   line(img,
       start,
       end,
       Scalar(0,0,0), // 黑色

int main(int argc, char ** argv)
   Mat atomImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);
   Mat rookImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);

// 椭圆绘制
   DrawEllipse(atomImage, 0);
   DrawEllipse(atomImage, 90);
   DrawEllipse(atomImage, 45);
   DrawEllipse(atomImage, -45);
   // 绘制圆心
   DrawFilledCircle(atomImage, Point(WINDOW_WIDTH / 2, WINDOW_WIDTH / 2));

// 绘制多边形
   DrawPolygon(rookImage);

// 绘制矩形
   rectangle(rookImage,
       Point(0, 7 * WINDOW_WIDTH / 8),
       Point(WINDOW_WIDTH, WINDOW_WIDTH),
       Scalar(0, 255, 255),
       -1,
       8);

// 绘制一些线段
   DrawLine(rookImage, Point(0, 15 * WINDOW_WIDTH / 16), Point(WINDOW_WIDTH, 15 * WINDOW_WIDTH / 16));
   DrawLine(rookImage, Point(WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8), Point(WINDOW_WIDTH / 4, WINDOW_WIDTH));
   DrawLine(rookImage, Point(WINDOW_WIDTH / 2, 7 * WINDOW_WIDTH / 8), Point(WINDOW_WIDTH / 2, WINDOW_WIDTH));
   DrawLine(rookImage, Point(3 * WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8), Point(3 * WINDOW_WIDTH / 4, WINDOW_WIDTH));

// ---------------------------<3>显示绘制出的图像------------------------
   imshow(WINDOW_NAME1, atomImage);
   moveWindow(WINDOW_NAME1, 0, 200);
   imshow(WINDOW_NAME2, rookImage);
   moveWindow(WINDOW_NAME2, WINDOW_WIDTH, 200);

waitKey(0);
   return(0);

运行：

参考：

《OpenCV3 编程入门》 毛星云 P104

来源：https://www.cnblogs.com/huvjie/p/15674797.html