简单opencv 外轮廓检测以加矩形框

#include 
#include 
#include
using namespace std;
using namespace cv;
int main() {
	   Mat threshold_output;
	   vector > contours;
	   vector hierarchy;
	   Mat src_gray;
	   Mat frame;
	  //自定义形态学元素结构
	   cv::Mat element5(9, 9, CV_8U, cv::Scalar(1));//5*5正方形，8位uchar型，全1结构元素  
	   Scalar color = Scalar(0, 0, 255);
	   cv::Mat closed;
	   Rect rect;
		frame = imread("./lunkuo.jpg");
		imshow("src", frame);
		Mat image = frame.clone();
		cvWaitKey(1000);
		cvtColor(frame, src_gray, COLOR_BGR2GRAY);
		//使用Canny检测边缘  
		Canny(src_gray, threshold_output, 80, 126, (3, 3));
		//高级形态学闭运算函数  
		cv::morphologyEx(threshold_output, closed, cv::MORPH_CLOSE, element5);
		imshow("canny", threshold_output);
		imshow("erode", closed);
		// 寻找外轮廓轮廓  
		findContours(closed, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_NONE, Point());
		cout << contours.size() << endl;
		for (int i = 0; i < contours.size(); i++)
		{

			for (int j = 0; j < contours[i].size(); j++)
			{
			
				cout << contours[i][j] << endl;
				//遍历轮廓中每个像素点并且赋值颜色
				//frame.at(contours[i][j].y, contours[i][j].x) = (0, 0, 255);
			}

		}
	    //转换轮廓点到最大外矩形框
		rect = boundingRect(contours[0]);
		rectangle(image,rect,color);
		//加矩形框后的图片
		imshow("rect", image);
		cvWaitKey(0);
	return 0;
}