Customization of UIImagePickerController

I am working on camera application in which I want to set the screen of the camera i.e camera window appear for particular frame. And in front of camera screen the 开发者_开发百科cut out image is coming so that user can see the background through the cut out part of the image and capture the image. So any one know to do this i.e. customization of UIImagePickerController.

UIImagePickerController has a property named cameraOverlayView. Use this to set your camera overlay as any view you like. Use normal view transparency for letting the user see parts of the live camera view.