OpenCV学习8--绘制形状和文字

在opencv\sources\samples下面提供了很多的官方例程，是学习OpenCV的最好的资源。

视频教程地址：

https://www.bilibili.com/video/av17748771/?p=8

感谢贾志刚老师的视频教程。

绘制形状

使用cv::Point与cv::Scalar

Point表示2D平面的一个点x,y

p = Point(10,8);

Scalar表示四个元素的向量

Scalar(a,b,c); //a=blue,b=green,c=red表示RGB三个通道

绘制线 cv::line(LINE_4\LINE_8\LINE_AA)

画椭圆 cv::ellipse

画矩形 cv::rectangle

画圆 cv::circle

画填充 cv::fillPoly

绘制文本

putText(src,”Hello girl”,Point(0,145),CV_FONT_HERSHEY_COMPLEX,1.0,Scalar(255,0,255),2,8);

代码

#include<iostream>
#include<opencv2/core/core.hpp>
#include<highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <math.h>

using namespace cv;
using namespace std;

void MyLines(Mat bg_img);
void MyRectangle(Mat bg_img);
void MyEllipse(Mat bg_img);
void MyCircle(Mat bg_img);
void MyPolygon(Mat bg_img);
void MyRandomDemo(Mat bg_img);

int main()
{
Mat src;
Mat src2;
src = imread("1.jpg");

char input_win[] = "input image";

namedWindow(input_win,CV_WINDOW_AUTOSIZE);
imshow(input_win,src);
src.copyTo(src2);
MyLines(src);
MyRectangle(src);
MyEllipse(src);
MyCircle(src);
MyPolygon(src);
putText(src,"Hello girl",Point(0,145),CV_FONT_HERSHEY_COMPLEX,1.0,Scalar(255,0,255),2,8);
namedWindow("out1",CV_WINDOW_AUTOSIZE);
imshow("out1",src);

MyRandomDemo(src2);

waitKey(0);
return 0;
}

void MyLines(Mat bg_img)
{
Point p1 = Point(20,30);
Point p2;
p2.x = 300;
p2.y = 300;
Scalar color = Scalar(0,0,255);
line(bg_img,p1,p2,color,1,8,0);
}

void MyRectangle(Mat bg_img)
{
Rect rect = Rect(30,20,140,130);  //起始坐标和长宽
Scalar color = Scalar(255,0,0);
rectangle(bg_img,rect,color,2,8);
}

void MyEllipse(Mat bg_img)
{
ellipse(bg_img,Point(bg_img.cols/2,bg_img.rows/2),Point(bg_img.cols/4,bg_img.rows/8),45,0,360,Scalar(0,255,0),2,8);
}

void MyCircle(Mat bg_img)
{
circle(bg_img,Point(bg_img.cols/2,bg_img.rows/2),60,Scalar(0,255,0),2,8);
}

void MyPolygon(Mat bg_img)
{
Point pts[1][5];
pts[0][0] = Point(30,30);
pts[0][1] = Point(30,60);
pts[0][2] = Point(60,60);
pts[0][3] = Point(60,30);
pts[0][4] = Point(30,30);
const Point *ppts[] = {pts[0]};
int npt[] = {5};
fillPoly(bg_img,ppts,npt,1,Scalar(0,255,255),8);
}

void MyRandomDemo(Mat bg_img)
{
RNG rng(12345); //生成随机数
Point pt1;
Point pt2;
namedWindow("out3",CV_WINDOW_AUTOSIZE);
Mat bg = Mat::zeros(bg_img.size(),bg_img.type());
for(int i = 0;i<10000;i++){
pt1.x = rng.uniform(0,bg_img.cols);
pt1.y = rng.uniform(0,bg_img.rows);
pt2.x = rng.uniform(0,bg_img.cols);
pt2.y = rng.uniform(0,bg_img.rows);
Scalar color = Scalar(rng.uniform(0,255),rng.uniform(0,255),rng.uniform(0,255));

if(waitKey(50) > 0){
break;
}
line(bg_img,pt1,pt2,color,1,8);
imshow("out3",bg_img);
}　
}

效果演示

　　


源码和原图片请到Github下载:

https://github.com/MRwangmaomao/OpencvDrawTest-Project.git