Disclosed herein are methods and systems for encoding digital watermarks
into content signals. Also disclosed are systems and methods for
detecting and/or verifying digital watermarks in content
signals.According to one embodiment, a system for encoding of digital
watermark information includes: a window identifier for identifying a
sample window in the signal; an interval calculator for determining a
quantization interval of the sample window; and a sampler for normalizing
the sample window to provide normalized samples.According to another
embodiment, a system for pre-analyzing a digital signal for encoding at
least one digital watermark using a digital filter is disclosed.According
to another embodiment, a method for pre-analyzing a digital signal for
encoding digital watermarks comprises: (1) providing a digital signal;
(2) providing a digital filter to be applied to the digital signal; and
(3) identifying an area of the digital signal that will be affected by
the digital filter based on at least one measurable difference between
the digital signal and a counterpart of the digital signal selected from
the group consisting of the digital signal as transmitted, the digital
signal as stored in a medium, and the digital signal as played
backed.According to another embodiment, a method for encoding a watermark
in a content signal includes the steps of (1) splitting a watermark bit
stream; and (2) encoding at least half of the watermark bit stream in the
content signal using inverted instances of the watermark bit stream.Other
methods and systems for encoding/decoding digital watermarks are also
disclosed.