1 #include "opencv2/imgcodecs.hpp"
2 #include "opencv2/highgui/highgui.hpp"
3 #include "opencv2/imgproc/imgproc.hpp"
4
5 #include <iostream>
6
7 using namespace cv;
8 using namespace std;
9
help()10 static void help()
11 {
12 cout << "\nThis program demonstrates circle finding with the Hough transform.\n"
13 "Usage:\n"
14 "./houghcircles <image_name>, Default is ../data/board.jpg\n" << endl;
15 }
16
main(int argc,char ** argv)17 int main(int argc, char** argv)
18 {
19 const char* filename = argc >= 2 ? argv[1] : "../data/board.jpg";
20
21 Mat img = imread(filename, 0);
22 if(img.empty())
23 {
24 help();
25 cout << "can not open " << filename << endl;
26 return -1;
27 }
28
29 Mat cimg;
30 medianBlur(img, img, 5);
31 cvtColor(img, cimg, COLOR_GRAY2BGR);
32
33 vector<Vec3f> circles;
34 HoughCircles(img, circles, HOUGH_GRADIENT, 1, 10,
35 100, 30, 1, 30 // change the last two parameters
36 // (min_radius & max_radius) to detect larger circles
37 );
38 for( size_t i = 0; i < circles.size(); i++ )
39 {
40 Vec3i c = circles[i];
41 circle( cimg, Point(c[0], c[1]), c[2], Scalar(0,0,255), 3, LINE_AA);
42 circle( cimg, Point(c[0], c[1]), 2, Scalar(0,255,0), 3, LINE_AA);
43 }
44
45 imshow("detected circles", cimg);
46 waitKey();
47
48 return 0;
49 }
50
