绘制形状与文字

VS2017&OPENCV4.0

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace std;
using namespace cv;

Mat bgImage;
const char* drawdemo_win = "draw shapes and text demo";
void MyLines();
void MyRectangle();
void MyEllipse();
void MyCircle();
void MyPolygon();
void RandomLineDemo();
int main(int argc, char** argv) {
	bgImage = imread("D:\\test.jpg");
	if (!bgImage.data) {
		printf("could not load image...\n");
		return -1;
	}
	MyLines();
	MyRectangle();
	MyEllipse();
	MyCircle();
	MyPolygon();

	putText(bgImage, "Hello OpenCV", Point(300, 300), FONT_HERSHEY_COMPLEX, 1.0, Scalar(12, 23, 200), 3, 8);
	namedWindow(drawdemo_win, WINDOW_AUTOSIZE);
	imshow(drawdemo_win, bgImage);

	RandomLineDemo();
	waitKey(0);
	return 0;
}

void MyLines() {//绘制线
	Point p1 = Point(20, 30);//线的起点
	Point p2;
	p2.x = 400;
	p2.y = 400;//线的终点
	Scalar color = Scalar(0, 0, 255);//线的颜色
	line(bgImage, p1, p2, color, 1, LINE_AA);
}

void MyRectangle() {//绘制矩形
	Rect rect = Rect(200, 100, 300, 300);//矩形的起点和线长
	Scalar color = Scalar(255, 0, 0);
	rectangle(bgImage, rect, color, 2, LINE_8);
}

void MyEllipse() {//绘制椭圆
	Scalar color = Scalar(0, 255, 0);
	ellipse(bgImage, Point(bgImage.cols / 2, bgImage.rows / 2), Size(bgImage.cols / 4, bgImage.rows / 8), 90, 0, 360, color, 2, LINE_8);
}

void MyCircle() {//绘制圆
	Scalar color = Scalar(0, 255, 255);
	Point center = Point(bgImage.cols / 2, bgImage.rows / 2);//圆的中心
	circle(bgImage, center, 150, color, 2, 8);
}

void MyPolygon() {//绘制多边形
	Point pts[1][5];//五边形
	pts[0][0] = Point(100, 100);
	pts[0][1] = Point(100, 200);
	pts[0][2] = Point(200, 200);
	pts[0][3] = Point(200, 100);
	pts[0][4] = Point(100, 100);

	const Point* ppts[] = { pts[0] };
	int npt[] = { 5 };
	Scalar color = Scalar(255, 12, 255);

	fillPoly(bgImage, ppts, npt, 1, color, 8);
}

void RandomLineDemo() {
	RNG rng(12345);//定义随机数
	Point pt1;
	Point pt2;
	Mat bg = Mat::zeros(bgImage.size(), bgImage.type());
	namedWindow("random line demo", WINDOW_AUTOSIZE);
	for (int i = 0; i < 100000; i++) {
		pt1.x = rng.uniform(0, bgImage.cols);//随机数产生，0到bgImage.cols
		pt2.x = rng.uniform(0, bgImage.cols);
		pt1.y = rng.uniform(0, bgImage.rows);//随机数产生，0到 bgImage.rows
		pt2.y = rng.uniform(0, bgImage.rows);
		Scalar color = Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255));//0到255产生随机数
		if (waitKey(50) > 0) {
			break;
		}
		line(bg, pt1, pt2, color, 1, 8);
		imshow("random line demo", bg);
	}
}