title: How to use function computeCorrespondEpilines() in OpenCV in C++
body: <p>I am using this code to find epipolar line (<a href="http://docs.opencv.org/2.4/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html" rel="nofollow noreferrer">source</a>).</p>
  
  <pre><code>#include &lt;iostream&gt;
  using namespace std;
  #include &lt;opencv2/opencv.hpp&gt;
  #include &lt;opencv2/core/core.hpp&gt;
  #include &lt;opencv2/highgui/highgui.hpp&gt;
  using namespace cv;
  
  
  int main(){
      int point_count = 8;
      vector&lt;Point2f&gt; points1(point_count);
      vector&lt;Point2f&gt; points2(point_count);
  
              points1[0] = Point2f(330, 123);
              points1[1] = Point2f(330,240);
              points1[2] = Point2f(260,223);
              points1[3] = Point2f(202,109);
              points1[4] = Point2f(204,207);
              points1[5] = Point2f(118,104);
              points1[6] = Point2f(41,174);
              points1[7] = Point2f(205,209);
  
              points2[0] = Point2f(268,89);
              points2[1] = Point2f(268,207);
              points2[2] = Point2f(212,191);
              points2[3] = Point2f(164,82);
              points2[4] = Point2f(168,176);
              points2[5] = Point2f(116,74);
              points2[6] = Point2f(29,143);
              points2[7] = Point2f(167,178);
  
  
      Mat fundamental_matrix = findFundamentalMat(points1, points2, FM_8POINT);
      cout&lt;&lt;"hello!!"&lt;&lt;endl;
      cout &lt;&lt; "fundamental Matrix ="&lt;&lt;endl&lt;&lt; " "  &lt;&lt; fundamental_matrix &lt;&lt; endl &lt;&lt; endl;
  
       computeCorrespondEpilines(points1, 1, fundamental_matrix);
  }
  </code></pre>
  
  <p>But I am getting error in function computeCorrespondEpilines()</p>
  
  <pre><code>Invalid arguments '
  Candidates are:
  void computeCorrespondEpilines(const cv::_InputArray &amp;, int, const cv::_InputArray &amp;, const cv::_OutputArray &amp;)
  '
  </code></pre>
  
  <p>I'm not sure how to use this function and confused about 2nd and last argument.
  Please point me in right direction,Thanks in advance. </p>