EMBEDDING WATERMARK FOR PROTECTING MULTIPLE COPIES OF A SIGNAL

摘要

The present invention relates to methods, devices and a signal related to simplifying the embedding of watermarks in different copies of a media signal (x). The watermarking process is split into two parts, one that is based on signal dependent properties and one that is based on watermark specific properties. The signal dependent properties are determined in advance, while the watermark specific properties are determined at the time of delivery of the media signal. The signal dependent watermarking properties (p) of a media signal (x) are determined in a properties determining unit (14) and stored in a signal properties store (16), such that the signal dependent properties can be used for embedding more than one watermark (WA, WB, WC) in different copies of the media signal. In this way it is possible to embed watermarks in multiple copies of the same media signal with small time delays.