title: Kitti Velodyne point to pixel coordinate
body: <p>From the Velodyne point, how to get pixel coordinate for each camera?</p>
  
  <p>Using <a href="https://github.com/utiasSTARS/pykitti#example" rel="nofollow noreferrer">pykitti</a> 
  <code>point_cam0 = data.calib.T_cam0_velo.dot(point_velo)</code>
  We can get the projection on the image which is equation 7 of the <a href="http://www.mrt.kit.edu/z/publ/download/2013/GeigerAl2013IJRR.pdf" rel="nofollow noreferrer">Kitti Dataset paper</a>:</p>
  
  <p>y = P<sub>rect</sub><sup>(i)</sup> R<sub>rect</sub><sup>(0)</sup> T<sub>velo</sub><sup>cam</sup> x</p>
  
  <p>But from there, how to get the actual pixel coordinates on each image?</p>