title: Detect the state/position of an object using computer vision
body: <p>I need to check whether an object has moved to a specific location. (In my case it is the position of a motorized window shade). I want to use computer vision / image recognition for this.</p>
  <p>For this I am thinking of comparing two images: The observed position vs the required position.</p>
  <p>I did some search on openCv and found concepts like circle detection (to apply certain markings on the shade which I could use) or template matching, but not being a computer vision expert (I know python though) I would really appreciate a push in the right direction.</p>
  <p>So I need some algorithm to check whether a shade is closed by comparing it to a referenced closed shade image, taken from the same angle etc, but taking into account some lighting variations..</p>