Preview’s Signature Feature…using Canny Edge Detector?

I finally upgraded to Lion because of Preview’s “Signature” feature. You sign your name on a sheet of paper, hold it up to the built-in camera, and your signature is digitally recreated so you can “sign” PDFs and forms!

Pretty neat. When i think about how it works, my mind goes straight to the Canny Edge Detector! And John Canny was my professor back at Berkeley! Pretty neat!