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 line finding with the Hough transform.\n"
13 "Usage:\n"
14 "./houghlines <image_name>, Default is ../data/pic1.png\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/pic1.png";
20
21 Mat src = imread(filename, 0);
22 if(src.empty())
23 {
24 help();
25 cout << "can not open " << filename << endl;
26 return -1;
27 }
28
29 Mat dst, cdst;
30 Canny(src, dst, 50, 200, 3);
31 cvtColor(dst, cdst, COLOR_GRAY2BGR);
32
33 #if 0
34 vector<Vec2f> lines;
35 HoughLines(dst, lines, 1, CV_PI/180, 100, 0, 0 );
36
37 for( size_t i = 0; i < lines.size(); i++ )
38 {
39 float rho = lines[i][0], theta = lines[i][1];
40 Point pt1, pt2;
41 double a = cos(theta), b = sin(theta);
42 double x0 = a*rho, y0 = b*rho;
43 pt1.x = cvRound(x0 + 1000*(-b));
44 pt1.y = cvRound(y0 + 1000*(a));
45 pt2.x = cvRound(x0 - 1000*(-b));
46 pt2.y = cvRound(y0 - 1000*(a));
47 line( cdst, pt1, pt2, Scalar(0,0,255), 3, CV_AA);
48 }
49 #else
50 vector<Vec4i> lines;
51 HoughLinesP(dst, lines, 1, CV_PI/180, 50, 50, 10 );
52 for( size_t i = 0; i < lines.size(); i++ )
53 {
54 Vec4i l = lines[i];
55 line( cdst, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0,0,255), 3, LINE_AA);
56 }
57 #endif
58 imshow("source", src);
59 imshow("detected lines", cdst);
60
61 waitKey();
62
63 return 0;
64 }
65
