title: Motion detection from camera live stream in iOS
body: <p>I am making an application in which i have to open the camera and track the motion from camera live video/stream. and then detect the number of faces in the current frame.</p>
  
  <p>I have done the face detection part by using CIDetector but unable to do the Motion detection.
  Can any one please guide me how to do it.</p>
  
  <p>I have used the GPUImage but it does not support multiple face detection.</p>