Using Classification Techniques in Digital Watermarking
AssigneeDigimarc Corporation
InventorHugh L. Brunk
Life of this patent
Estimating the term…
Abstract
A classification scheme assigns samples of the watermarked media to classes based on classification criteria indicating a likely presence of a watermarked signal. Once classified, the scheme determines statistical characteristics of the media signal for the classes, and assigns a figure of merit to the samples in each class. A watermark decoder (e.g., reader and/or detector) use the figure of merit to adapt a watermark decoding function to the statistical features of the classes, such as weighting to samples to improve watermark decoding.
Claims20
A method for reading a digital watermark in a media signal comprising:
- using a computer programmed to perform the acts of:
- assigning sets of media signal samples into classes;
- computing statistical characteristics of the media samples for the classes;
- and
- using the statistical characteristics to adapt a digital watermark decoding function used to detect or read a watermark in the media signal.
A method for reading a digital watermark in a media signal comprising:
- using a computer programmed to perform the acts of:
- assigning transformed samples of the media signal into classes using characteristics computed from the samples to group the samples into the classes;
- computing statistical characteristics of the samples in each of the classes to compute a statistical feature of each of the classes;
- and
- using the statistical feature to compute a detection metric to decode a watermark from the samples.
A method for reading a digital watermark in a watermarked signal comprising:
- using a computer programmed to perform the acts of:
- assigning samples of the watermarked signal into classes using characteristics computed from the samples to group the samples into the classes;
- computing a statistical analysis of the samples in each of the classes;
- and
- using the statistical analysis to compute a decoding function for decoding a watermark from the watermarked signal.
A method for estimating a watermark signal from a media signal suspected of containing the watermark signal, the method comprising:
- using a computer programmed to perform the acts of:
- assigning samples of the suspect signal into classes based on a signal characteristic of the samples;
- calculating statistical characteristics of the classes;
- and
- estimating the watermark signal based on the suspect signal, the statistical characteristics of the classes, and a characteristic of the watermark signal.
Dependencies are inferred from the claim text.