title: error: ‘calcOpticalFlowPyrLK’ is not a member of ‘cv’ - OpenCV 2.4.2
body: <p>I'm having this error on OpenCV 2.4.2 about this.</p>
  
  <p>I'm using this line of code:</p>
  
  <pre><code> cv::calcOpticalFlowPyrLK(prev, next, prev_pts, next_pts, status, error);
  </code></pre>
  
  <p>And on compile time it shows this error:</p>
  
  <pre><code>testopticalflow.cpp:75:4: error: ‘calcOpticalFlowPyrLK’ is not a member of ‘cv’
  </code></pre>
  
  <p>This is the result if I use pkg-config</p>
  
  <pre><code>pkg-config opencv --libs
  /usr/local/lib/libopencv_calib3d.so /usr/local/lib/libopencv_contrib.so /usr/local/lib/libopencv_core.so /usr/local/lib/libopencv_features2d.so /usr/local/lib/libopencv_flann.so /usr/local/lib/libopencv_gpu.so /usr/local/lib/libopencv_highgui.so /usr/local/lib/libopencv_imgproc.so /usr/local/lib/libopencv_legacy.so /usr/local/lib/libopencv_ml.so /usr/local/lib/libopencv_nonfree.so /usr/local/lib/libopencv_objdetect.so /usr/local/lib/libopencv_photo.so /usr/local/lib/libopencv_stitching.so /usr/local/lib/libopencv_ts.so /usr/local/lib/libopencv_video.so /usr/local/lib/libopencv_videostab.so  
  </code></pre>
  
  <p>Sorry I'm still a newbie when it comes to Linux environment so I have no idea where I went wrong.</p>