Watermark generator using differential encoding, watermark decoder, method for providing watermark signal based on binary message data, method for providing binary message data based on watermarked signal, and computer program

摘要

A watermark generator (2400) for providing a watermark signal (2420) in dependence on binary message data (2410), comprises an information processor (2430) configured to provide, in dependence on information units of the binary message data, a first time-frequency domain representation (2432), values of which represent the binary message data. The watermark generator also comprises a differential encoder (2440) configured to derive a second time-frequency domain representation (2442) from the first time-frequency-domain representation, such that the second time-frequency-domain representation comprises a plurality of values, wherein a difference between two values of the second time-frequency-domain representation represents a corresponding value of the first time-frequency-domain representation, in order to obtain a differential encoding of the values of the first time-frequency-domain representation. The watermark generator also comprises a watermark signal provider (2450) configured to provide the watermark signal on the basis of the second time-frequency-domain representation.