WATERMARK EMBEDDING AND DETECTION

摘要

A method and arrangement for embedding and detecting a watermark in an information signal is disclosed. The embedded watermark (Wi) is selected (13) from a plurality of watermarks (W1..WN) in dependence upon a property P of the signal. An example of such a property is the distribution of luminance values of the current video image as calculated by an analysis circuit (12). The corresponding watermark detector performs the same operation: the watermark being looked for depends on the same signal property. It is achieved with the invention that the embedded watermark changes from time to time as a function of the information signal content, so that it cannot easily be hacked.