Patent attributes
The present invention relate generally to digital watermarking. One claim recites an apparatus comprising: electronic memory for buffering a color video signal comprising a first frame and a second frame; and one or more electronic processors programmed for: transforming a first color channel and a second color channel of the first frame by hiding a digital watermark in the first color channel such that the first digital watermark includes a first signal polarity, and hiding the digital watermark in the second color channel such that the digital watermark includes a second signal polarity that is inversely related to the first signal polarity; transforming a first color channel and a second color channel of the second frame by hiding a digital watermark in the first color channel such that the first digital watermark includes the second signal polarity, and hiding the digital watermark in the second color channel such that the digital watermark includes the first signal polarity. Of course, different combinations and claims are provided too.