Embedding supplemental data in an information signal

Abstract

An arrangement for embedding supplemental data (e.g. a watermark W) in an information signal. In an embodiment of the invention, the arrangement comprises a conventional sigma-delta modulator for encoding an audio signal and modifying means for periodically replacing a bit of the encoded signal by a bit of the watermark. In the same manner, a sync pattern is embedded in the signal. The sync bits are embedded at a smaller distance than the watermark bits. Preferably, the sync pattern is a pattern of contiguous bits which is typically not generated by the encoder. For the sigma-delta modulator, such a pattern is a run of ones followed by a substantially equally long run of zeroes, or vice versa.

Dependencies are inferred from the claim text.