Cannot add an overlay over the camera image

[energywave]

As the subject, I've tried to add any type of overlay over the camera image by putting the views in an AbsoluteLayout.
The result, however, is that the image (as a drawable vectorial xml, as a drawable png or by a Path view directly) have a white background, even if I specified the BackgroundColro="Transparent".
It's something like nothing can be put over the camera stream preview.
I don't know how the things are but, as in the zxing component, it's important to put an overlay so that user can focus on position the QR code in the right spot. Can you help me in understanding a viable method to do it please?
Thank you in advance for your time!

[RhomGit]

You should have no problems rendering your own overlay.
If its an all white bg make sure you have set the IsScanning property on the control to true ;)