title: Tracking user defined points with OpenCV
body: <p>I'm working on a project where I need to track two points in an image. So far, the best way I have of identifying these points is to get the user to click on them when the program is first run. I'm using the Lucas-Kanade Pyramid method built into OpenCV (<a href="http://docs.opencv.org/modules/video/doc/motion_analysis_and_object_tracking.html" rel="nofollow">documented here</a>, but as is to be expected, this doesn't work too well. Is there a better alternative algorithm for tracking points in OpenCV, or alternatively some other way of verifying the points I already have?<br>
  I'm currently considering using GoodFeaturesToTrack, and getting the distance from each point to the one that I want to track, and maybe some sort of vector pointing out the relationship between the two points, and using this information to determine my new point. 
  I'm looking for suggestions of ways to go about this, not necessarily code samples.
  Thanks </p>
  
  <p>EDIT: I'm tracking small movements, if that helps</p>