title: Detect and extract face from an image
body: <p>I have been trying to do the following - 
  When a user uploads an Image in my web app, I'd like to detect his/her face in it and extract face (from forehead to chin and cheek to cheek) from it.</p>
  
  <ul>
  <li><p>I tried OpenCV/C++ face detection using Haar Cascade but problem with it is that it gives a probability of where the face would be because of which either background of image comes inside the ROI or even the complete face doesn't come in the ROI.
  I also want to detect eye inside the face and while using the above technique, the eye detection isn't that accurate.</p></li>
  <li><p>I've read up on a new technique called <a href="https://code.google.com/p/asmlib-opencv/" rel="nofollow">Active Appearance Model (AAM</a>). The <a href="http://codecapsule.com/2010/08/12/active-appearance-models-in-c-plus-plus/" rel="nofollow">blogs</a> where I read up about this show that this is exactly what I want but I am lost on how to implement this.</p></li>
  </ul>
  
  <p>My queries are - </p>
  
  <ol>
  <li>Is using AAM a good idea for face detection and face feature detection.</li>
  <li>Are there any other techniques for doing the same.</li>
  </ol>
  
  <p>Any help on any of these is much appreciated.</p>
  
  <p>Thanks !</p>