title: How to calculate normalized image coordinates from pixel coordinates?
body: <p>I need to calculate 3D points from corresponding images points. The algorithm to do this is explained here: <a href="http://en.wikipedia.org/wiki/Essential_matrix" rel="noreferrer">http://en.wikipedia.org/wiki/Essential_matrix</a>. It is not working for me, I receive wrong results. 
  1. Procedure utilize "normalized image coordinates" - how can I calculate them?
  2. R and T matrices (calculated from essential matrix) are the same as these which outputs from cv::stereocalibrate procedure?</p>
  
  <p>This is what i am doing now:</p>
  
  <ol>
  <li>Stereo calibrate my setup</li>
  <li>Inverse camera matrix for both cameras</li>
  <li>Calculate the normalized coordinates of corresponding points for both cameras - by  multipication of inversed camera matrix and homogenous pixel point coordinates</li>
  </ol>
  
  <p>Rest operations are based on this article <a href="http://en.wikipedia.org/wiki/Essential_matrix" rel="noreferrer">http://en.wikipedia.org/wiki/Essential_matrix</a> in section: 3D points from corresponding image points</p>
  
  <ol>
  <li>Calculating x3 physical/real world coordinate of the point using Rotation and Translation matrices (given by stereo calibration procedure). </li>
  <li>Calculating x1 and x2 coordinates as it is written in the article</li>
  </ol>
  
  <p>Thanks for your help.</p>