Find contour example source code

Find Contour example source code

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#include "opencv2/opencv.hpp"
#include "opencv2/highgui.hpp"
#include <iostream>
#include <vector>

#ifdef _DEBUG               
#pragma comment(lib, "opencv_core331d.lib")       
#pragma comment(lib, "opencv_highgui331d.lib")    
#pragma comment(lib, "opencv_imgcodecs331d.lib")  
#pragma comment(lib, "opencv_objdetect331d.lib")  
#pragma comment(lib, "opencv_imgproc331d.lib")  
#pragma comment(lib, "opencv_videoio331d.lib")    
#else       
#pragma comment(lib, "opencv_core331.lib")       
#pragma comment(lib, "opencv_highgui331.lib")    
#pragma comment(lib, "opencv_imgcodecs331.lib")    
#pragma comment(lib, "opencv_objdetect331.lib")  
#pragma comment(lib, "opencv_imgproc331.lib")  
#pragma comment(lib, "opencv_videoio331.lib")    
#endif        


using namespace std;
using namespace cv;

int main()
{
    Mat img(500, 500, CV_8UC3);
    img.setTo(255);

    cvtColor(img, img, CV_RGB2GRAY);
    img.setTo(0);
    rectangle(img, Rect(10, 10, 200, 200), CV_RGB(255, 255, 255), CV_FILLED);
    imshow("show1", img);

    Mat dst = Mat::zeros(img.rows, img.cols, CV_8UC3);
    vector< vector< Point> > contours;
    vector< Vec4i> hierarchy;

    findContours(img.clone(), contours, hierarchy,
        RETR_CCOMP, CHAIN_APPROX_SIMPLE);

    // iterate through all the top-level contours,
    // draw each connected component with its own random color
    int idx = 0;
    for (; idx >= 0; idx = hierarchy[idx][0])
    {
        Scalar color(rand() & 255, rand() & 255, rand() & 255);
        //drawContours(dst, contours, idx, color, FILLED, 8, hierarchy);
        drawContours(dst, contours, idx, color, 1, 8, hierarchy);
    }

    imshow("show2", dst);

    waitKey(0);

    return 0;
}

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