title: Detect marker in 2D image
body: <p>I am hoping to obtain some some help with 2D object detection. I'll give a brief overview of the context in which this will be implemented. </p>
  
  <p>There will be an image taken of the ceiling. The ceiling will have markers placed on it so the orientation of the camera can be determined. The pictures will always be taken facing straight up. My goal is to detect one of these markers in the image and determine its rotation. So rotation and scaling(to a lesser extent) will be the two primary factors used in the image detection. I will be writing the software in either C# or matlab(not quite sure yet). </p>
  
  <p>For example, the marker might be an arrow like this:</p>
  
  <p><img src="https://i.stack.imgur.com/IB5zt.png" alt="Reference Arrow"></p>
  
  <p>An image taken of the ceiling would contain markers. The software needs to detect a single marker and determine that it has been rotated by 170 degrees.</p>
  
  <p><img src="https://i.stack.imgur.com/KC23B.png" alt="Ceiling Arrows"></p>
  
  <p>I have no prior experience with image analysis. I know image processing is a fairly broad topic and was hoping to get some advice on which direction I should take and which techniques would be best for my application. Thanks!</p>