title: How can I compute orthographical projection image from perspective projection image?
body: <p>My goal is to transform an image captured by a camera and transform that image to orthographical image without effects of perspective.</p>
  <p>I have a few objects of known size on a surface. I have a camera, placed above and directed to those objects, as exemplified in <a href="https://i.stack.imgur.com/pny44.png" rel="nofollow noreferrer">the scene</a>. The camera is capturing images as in <a href="https://i.stack.imgur.com/GdcS2.png" rel="nofollow noreferrer">image captured by the camera</a>. I want to get an orthographical image of the environment as in <a href="https://i.stack.imgur.com/Znqlg.png" rel="nofollow noreferrer">orthographical image I want to get</a>.</p>
  <p>I have read few posts, but did not really understand their relevance to my problem, as I am not expert on these transforms. <a href="https://stackoverflow.com/questions/23719474/converting-perspective-projection-to-orthogonal-projection">The answer from this question</a> made me think it is possible, although I did not get how.</p>
  <p>I would appreciate a clear explanation or pointing a clear tutorial, using Python or Lua if possible.</p>
  <p>Any help is appreciated.</p>