title: Opencv Object tracking and count objects which passes ROI in video frame
body: <p>I am working on Opencv application that need to count any object which motion can be detected by the camera. The camera is still and I did the object tracking with opencv and cvblob by referring many tutorials. </p>
  
  <p>I found some similar question:
  <a href="https://stackoverflow.com/questions/20143577/opencv-multiply-objects-in-out-counting">Object counting</a></p>
  
  <p>And i found this was similar
  <a href="http://labs.globant.com/uncategorized/peopletracker-people-and-object-tracking/" rel="nofollow noreferrer">http://labs.globant.com/uncategorized/peopletracker-people-and-object-tracking/</a></p>
  
  <p>I am new to OpenCV and I've gone through the opencv documentation but I couldn't find anything which is related to count moving objects in video.</p>
  
  <p>Can any one please give me a idea how to do this specially the counting part. As I read in article above, they count people who crosses the virtual line.Is there a special algorithm to detect the object crossing the line?</p>