converted houghlines to C++

samples/cpp/houghlines.cpp

@@ -0,0 +1,55 @@
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+int main(int argc, char** argv)
+{
+    const char* filename = argc >= 2 ? argv[1] : "pic1.png";
+    
+    Mat src = imread(filename, 0);
+    if(src.empty())
+    {
+        cout << "can not open " << filename << endl;
+        cout << "Usage: houghlines <image_name>" << endl;
+    }
+
+    Mat dst, cdst;
+    Canny(src, dst, 50, 200, 3);
+    cvtColor(dst, cdst, CV_GRAY2BGR);
+    
+#if 0
+    vector<Vec2f> lines;
+    HoughLines(dst, lines, 1, CV_PI/180, 100, 0, 0 );
+    
+    for( size_t i = 0; i < lines.size(); i++ )
+    {
+        float rho = lines[i][0], theta = lines[i][1];
+        Point pt1, pt2;
+        double a = cos(theta), b = sin(theta);
+        double x0 = a*rho, y0 = b*rho;
+        pt1.x = cvRound(x0 + 1000*(-b));
+        pt1.y = cvRound(y0 + 1000*(a));
+        pt2.x = cvRound(x0 - 1000*(-b));
+        pt2.y = cvRound(y0 - 1000*(a));
+        line( cdst, pt1, pt2, Scalar(0,0,255), 3, CV_AA);
+    }
+#else
+    vector<Vec4i> lines;
+    HoughLinesP(dst, lines, 1, CV_PI/180, 50, 50, 10 );
+    for( size_t i = 0; i < lines.size(); i++ )
+    {
+        Vec4i l = lines[i];
+        line( cdst, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0,0,255), 3, CV_AA);
+    }
+#endif
+    imshow("source", src);
+    imshow("detected lines", cdst);
+
+    waitKey();
+    return 0;
+}
+