Webcam Signature Capturer

I want to have a script built that when activated will bring up the users webcam, then they can hold a piece of white paper with black writing of their signature on it. When they line the signature up just right (on the overlaid line on top of webcam), the program then is able to grab that and convert to a vector image and inserted into the page (and can be resized to fit).

In other words a digital webcam signature grabber.