title: Optimal Face-Detection Picture/Schematic
body: <p>I have a face-detection-algorithm that works great and fast (iOS' default CIDetector) when I use it to detect real human faces.
  Now I want to detect a test-image I put on a screen somewhere in a room, so I have total control of the image-to-be-detected, the only thing I need to be very sure about is the size on the screen.</p>
  
  <p>I tested it with a simple smiley painted on an HTML5 Canvas (like this: <img src="https://i.stack.imgur.com/KUTmb.png" alt="enter image description here">
  which is recognized as a face, but not as fast &amp; often as an actual image would (like this: <img src="https://i.stack.imgur.com/0nmDt.jpg" alt="enter image description here">.</p>
  
  <p>As you can expect it's really hard to google this, is there sort of a goto-schematic picture with really pronounced facial features that people use?</p>
  
  <p>EDIT: If someone knows a good algorithm to reverse-engineer the perfect image for an existing, black-box face-detection, then this would also solve the problem ;)</p>