WATERMARK GENERATOR, WATERMARK DECODER, METHOD FOR PROVIDING A WATERMARK SIGNAL IN DEPENDENCE ON BINARY MESSAGE DATA, METHOD FOR PROVIDING BINARY MESSAGE DATA IN DEPENDENCE ON A WATERMARKED SIGNAL AND COMPUTER PROGRAM USING A DIFFERENTIAL ENCODING

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.