This application relates, e.g., to processing video and audio. One claim recites a method including: utilizing a multi-purpose electronic processor programmed for analyzing a video signal to derive or calculate an identifier from data representing picture elements of the video signal or from data representing...http://www.google.se/patents/US7577273?utm_source=gb-gplus-sharePatent US7577273 - Steganographically encoded video, deriving or calculating identifiers from video, and related methods
