title: Making beneath image by dragging a circle over it in android
body: <p>In my implementation, I have two images, one layed over the other. As, I move a circle object over the top image, I want to make that area inside circle transperent, so that I can see the beneath image. For example I have two images - a car image and its framework image. I overlay car image over framweork image and as i drag a circle over car image, it should show the beneath framework. </p>
  
  <p>I tried to search a lot but not getting any pointers. Somewhere I read that I need to use alpha masking or image masking using porterduff and xfermode. but I did not understand.</p>
  
  <p>Specifically,</p>
  
  <p>How can I make the above image transperent and how can I only make the area inside circle transperent?</p>
  
  <p>Thank You</p>