title: How to get raw depth values from Kinect depth stream?
body: <p>I am tracking the motion of a human body using Lucas Kanade algorithm. I am working on RGB and Depth streams of Kinect. I have to place some points on the body, and track those points. Finally their xyz co-ordinates have to be calculated. </p>
  
  <p>My question is, how to get z coordinate for a particular pixel from the depth stream? I know Depth raw depth values  for kinect lie in 0-2047 range..and applying formulas on it can get me the distance in any units I want. But how to get this raw depth? Can anyone help?</p>
  
  <p>I am using libfreenect driver for kinect and opencv. </p>