Counting human movement of exercise using ROI or pre-set passing line with OpenCV I'm currently doing my final year Degree in computing studies. 

The project I'm working on is a video of a webcam or computer webcam to have 2 pre-defined ROI (Region of Interest) on top and bottom of the video. It is to detect a person when he does a simple push up whether he reaches the area of both top and bottom ROI by detecting the person's head when he enters the ROI. I totally have very less experience in programming and really need guide and help. 

During my research I've come across a journal/research at: Pattern Recognition Letters 33 (2012) 438–445. I've downloaded and gone thru it but can't seem to find its code or truly understand it. I got access with my University account at sciencedirect.com.

2nd idea I had was after viewing a video in Youtube: Traffic Counting based on OpenCV... I was very interested by that video. I was thinking if I could set 2 lines like he did and detect simple human motion up and down doing a simple accurate pushup exercise I would be so much happy but I can't seem to get contact or ask for any information. 

I really need advice and help because I am really lost.
This might help partially - 

You can, possibly track the person's head from his hair color(usually black), so can be distinguished from the background. This tracking just needs a simple RGB Filter like ( r&lt;val2 &amp;&amp; g&lt;val4 &amp;&amp; b&lt;val3). Then, you can calibrate the program to respond when the centroid of that hair-region crosses your desired lines/boundaries.