title: Transform Point with Perspective Transform Matrix
body: <p>I have the coordinates of a quadrilateral which was photographed out of two different perspectives. Furthermore I have the coordinates of one Point but only from one of the two perspectives. I need to transform the coordinates of this point to the perspective the second photograph of the rectangle was made. Do do this I use OpenCV</p>
  
  <p>I've calculated the Perspective Transform Matrix:</p>
  
  <pre><code>cv::getPerspectiveTransform(quad1, quad2);
  </code></pre>
  
  <p>My Problem now is that I don't really know how to transform the Point with the calculated Perspective Transform Matrix. This is probably quite simple but I just don't know how to do it.</p>