A watermarked signal is pre-filtered based on an analysis of signal
characteristics that identify filter parameters that yield better
correspondence between the filtered watermarked signal and the digital
watermark. The watermark detection method computes signal characteristics
of a host digitally watermarked signal, and analyzes the characteristics
to determine an extent to which the signal characteristics correspond to
characteristics of the digital watermark. The method adapts parameters of
digital watermark prediction applied to the watermarked signal based on
the extent to which the signal characteristics correspond to the
characteristics of the digital watermark. In one embodiment, different
filters or filter parameters are selected to match different signal
characteristics of the watermarked signal with the characteristics of the
digital watermark.