Methods and systems for time-frequency domain watermarking of media
signals, such as audio and video signals. An encoding method divides the
media signal into segments, transforms each segment into a time-frequency
representation, and computes a time-frequency domain watermark signal
based on the time frequency representation. It then combines the
time-frequency domain watermark signal with the media signal to produce a
watermarked media signal. To embed a message using this method, one may
use peak modulation, pseudorandom noise modulation, statistical feature
modulation, etc. Watermarking in the time-frequency domain enables the
encoder to perceptually model time and frequency attributes of the media
signal simultaneously. A watermark decoder uses a calibration signal to
detect the watermark signal in a potentially distorted version of the
watermarked signal. The calibration signal may also be used to determine
the watermark's alignment and scaling. After compensating for the
alignment and scaling, a watermark reader extracts an embedded message
from a time frequency representation of the media signal.