Watermark embedding method and arrangement

摘要

An arrangement for embedding a watermark in an information signal is disclosed. In order to make the embedded watermark more robust against hacking, a property of the watermark is randomized (11) which is irrelevant for the watermark detection. One example is randomizing (111) the magnitudes (abs) of the Fourier transformed watermark. Another example is randomly shifting the spatial or temporal position of the watermark with respect to the signal at a relatively low temporal frequency. The invention allows embedding (13) of spatially different watermarks without affecting the performance of a detector.