title: How to detect simple geometric shapes using OpenCV
body: <p>I have this project where I need (on iOS) to detect simple geometric shapes inside an image.</p>
  
  <p><img src="https://i.stack.imgur.com/pKJN7.png" alt="enter image description here"></p>
  
  <p>After searching the internet I have concluded that the best tool for this is OpenCV. The thing is that up until two hours ago I had no idea what OpenCV is and I have never even remotely did anything involving image processing. My main experience is JS/HTML,C#,SQL,Objective-C...</p>
  
  <p>Where do I start with this?</p>
  
  <p>I have found this <a href="https://stackoverflow.com/questions/9663841/how-to-extract-simple-geometric-forms-from-contours-in-opencv">answer</a> that I was able to digest and by reading already other stuff, I understand that OpenCV should return an Array of shapes with the points/corners, is this true? Also how will it represent a circle or a half circle? 
  Also what about the shape orientation?</p>
  
  <p>Do you know of any Demo iOS project that can demonstrate a similar functionality? </p>