Patent ID: 9514500
Filing Date: 2016-12-06
CPC Classification: G06T,G10L,H04N

Claim Text:
1. A watermark generator for providing a watermark signal as a sequence of subsequent watermark coefficients based on a stream of subsequent stream values representing discrete valued data, the watermark generator comprising: a differential encoder configured to provide the watermark signal, wherein the differential encoder is configured to apply a phase rotation to a current stream value of the stream values representing the discrete valued data or to a current watermark symbol, the current watermark symbol corresponding to a current stream value of the stream values representing the discrete valued data, to acquire a current watermark coefficient of the watermark signal; wherein the differential encoder is configured to derive a phase of a previous spectral coefficient of a watermarked signal which is a combination of a host signal and the watermark signal; wherein the differential encoder is configured to provide the watermark signal such that a phase angle of the phase rotation applied to the current stream value or the current watermark symbol is dependent on the phase of the previous spectral coefficient of the watermarked signal; wherein the host signal is an audio signal, an image signal or a video signal, and the watermarked signal is an audio signal, an image signal or a video signal; and wherein the differential encoder is implemented using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.