title: Translating Screen Coordinates [ x, y ] to Camera Pan and Tilt angles
body: <p>I have a IP Camera which can PTZ. I am currently streaming live feed into the browser and want to allow user to click a point on the screen and the camera will pan and tilt so that the user clicked position will now become the center point of view.</p>
  
  <p>my Camera Pan 360 degrees and Tilt from -55 to 90.</p>
  
  <p>any algorithm that will guide to me achieve my goal ??</p>