REVERSIBLE WATERMARKING OF DIGITAL SIGNALS

摘要

The invention relates to methods, devices, a system of devices and a signal where additional information is embedded in media content. The system includes a device (10) providing additional information (O, D) in a signal (y) having media content, comprising a first mapping unit (14) mapping the amplitude values of the media content onto first new values, and a multiplexing unit (16) inserting the additional information into the mapped media content. The system also includes a device (12) for receiving additional information (O, D) in a signal (y) having media content, comprising a demultiplexing unit (22) arranged to receive a signal including media content (xQ) the amplitude values of which have been mapped onto first new values together with additional embedded information (O, D), and remove the additional information from the mapped media content. The invention allows insertion of watermarks into media content such as audio.