title: Probabilistic hough transform openCV
body: <p>I'm trying to obtain only vertical lines in the image using the probabilistic hough function. Right now I have it detecting lines perfectly, but I need to modify it to show only vertical lines. Can someone point me in the right direction? Thank you.</p>
  
  <pre><code>     HoughLinesP(edges, linesP, 1, CV_PI/180, 50, 50, 10 );
   printf("Probabilistic Hough found %ld lines\n",linesP.size());
   // Draw the lines extracted
   cvtColor(edges, coloredges, CV_GRAY2BGR);
  vector&lt;Vec2f&gt; VlinesP;
   for( size_t i = 0; i &lt; linesP.size(); i++ ) 
   {
     Vec4i l = linesP[i]; 
     line( coloredges, Point(l[0], l[1]), Point(l[2], l[3]), Scalar(0,0,255), 1, CV_AA);
   }
   imshow("Probabilistic Hough detected lines", coloredges);
   waitKey(0);
  
   return 0;
  }
  </code></pre>