title: how to capture an image in background without using the camera application
body: <p>I have an android app which consists of a Button.<br>
  When you click on Button, an image should be captured from the camera without opening the camera application (the image should be captured in background).<br>
  How to implement this feature?<br>
  Any suggestions will be of great help.<br>
  Thanks a lot in advance.</p>