The disclosure describes methods for using digital watermarking to authenticate digital media signals, such as images, audio and video signals. It also describes techniques for using embedded watermarks to repair altered parts of a media signal when alteration is detected. Alteration is detected using...http://www.google.com.tw/patents/US8032758?utm_source=gb-gplus-share專利 US8032758 - Content authentication and recovery using digital watermarks
