OpenCV3.4.9

1.编译命令

g++ main.cpp -I /usr/local/include -L/usr/local/lib -lopencv_imgproc -lopencv_core -lopencv_imgcodecs -ldl

2.代码

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

using namespace std;
using namespace cv;

int main()
{
	//1. Read picture
	cv::Mat src = imread("test.jpg");
	
	//2. Draw rectangle
	cv::rectangle(src, Point(0, 0), Point(100, 100), Scalar(0, 255, 0), 5, LINE_8, 0);
	
	//3. Written file
	cv::imwrite("out.jpg", src);
	
	return 0;
}