OpenCV 霍夫线变换

 #include "opencv2/highgui/highgui.hpp"
 #include "opencv2/imgproc/imgproc.hpp"
 
 #include <iostream>
 
 using namespace cv;
 using namespace std;
 
 void help()
 {
  cout << "\nThis program demonstrates line finding with the Hough transform.\n"
          "Usage:\n"
          "./houghlines <image_name>, Default is pic1.jpg\n" << endl;
 }
 
 int main(int argc, char** argv)
 {
  const char* filename = argc >=  ? argv[] : "pic1.jpg";
 
  Mat src = imread(filename, );
  if(src.empty())
  {
      help();
      cout << "can not open " << filename << endl;
      return -;
  }
 
  Mat dst, cdst;
  Canny(src, dst, , , );
  cvtColor(dst, cdst, CV_GRAY2BGR);
 
  #if 0
   vector<Vec2f> lines;
   HoughLines(dst, lines, , CV_PI/, , ,  );
 
   for( size_t i = ; i < lines.size(); i++ )
   {
      float rho = lines[i][], theta = lines[i][];
      Point pt1, pt2;
      double a = cos(theta), b = sin(theta);
      double x0 = a*rho, y0 = b*rho;
      pt1.x = cvRound(x0 + *(-b));
      pt1.y = cvRound(y0 + *(a));
      pt2.x = cvRound(x0 - *(-b));
      pt2.y = cvRound(y0 - *(a));
      line( cdst, pt1, pt2, Scalar(,,), , CV_AA);
   }
  #else
   vector<Vec4i> lines;
   HoughLinesP(dst, lines, , CV_PI/, , ,  );
   for( size_t i = ; i < lines.size(); i++ )
   {
     Vec4i l = lines[i];
     line( cdst, Point(l[], l[]), Point(l[], l[]), Scalar(,,), , CV_AA);
   }
  #endif
  imshow("source", src);
  imshow("detected lines", cdst);
 
  waitKey();
 
  return ;
 }