Patent US6674876B1 successfully refreshed from Google Patents.
US6674876B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Watermarking in the time-frequency domain
Assignee: Digimarc Corp
•
Filing: 2000-09-14
•
Granted: 2004-01-06
•
Expires: 2020-09-14
Abstract
Abstract 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.
Inventors
- 👤 Brett T. Hannigan
- 👤 Kenneth L. Levy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:03
CPC Classifications
G; G06; G06T; G06T1/00; G06T1/0021; G06T1/0028; H; H04; H04N; H04N19/00; H04N19/46; H04N19/467; H04N21/00; H04N21/80; H04N21/83; H04N21/835; H04N21/8358; G06T2201/00; G06T2201/005; G06T2201/0052
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
164 words
A method of watermarking a media signal with a temporal component, the method comprising: dividing at least a portion of the media signal into segments; processing each segment with the following actions; moving a window along the media signal in the segment and repeatedly applying a frequency transform to the media signal in each window to generate a time-frequency representation, wherein the time-frequency representation includes a time axis and a frequency axis and elements in the representation correspond to a value at a particular time and a particular frequency; computing a perceptually adaptive watermark in the time-frequency domain, converting the watermark signal to the time domain using an inverse frequency transform and repeating the process until each segment has been processed; adding the watermark signal to the media signal to generate a watermarked media signal; down-sampling the segments before computing the time frequency representation; upsampling the converted watermark signal; wherein adding the media signal comprises adding the upsampled watermark signal to the media signal.
Claim 2
Independent Claim
164 words
A method of watermarking a media signal with a temporal component, the method comprising: dividing at least a portion of the media signal into segments; processing each segment with the following actions; moving a window along the media signal in the segment and repeatedly applying a frequency transform to the media signal in each window to generate a time-frequency representation, wherein the time-frequency representation includes a time axis and a frequency axis and elements in the representation correspond to a value at a particular time and a particular frequency; computing a perceptually adaptive watermark in the time-frequency domain, converting the watermark signal to the time domain using an inverse frequency transform and repeating the process until each segment has been processed; adding the watermark signal to the media signal to generate a watermarked media signal; down-sampling the segments before computing the time frequency representation; upsampling the converted watermark signal; wherein adding the media signal comprises adding the upsampled watermark signal to the media signal.
Claim 3
Independent Claim
91 words
A method of time-frequency domain watermarking of a media signal comprising: converting the media signal into a time-frequency domain representation, wherein the time-frequency domain representation includes a time axis and a frequency axis and elements in the representation correspond to a value at a particular time and a particular frequency, embedding a watermark in the time frequency domain representation to produce a watermarked signal in the time frequency domain, and converting the watermarked signal from the time-frequency domain into a domain in which the signal is perceived by viewers or listeners.
Claim 4
Independent Claim
91 words
A method of time-frequency domain watermarking of a media signal comprising: converting the media signal into a time-frequency domain representation, wherein the time-frequency domain representation includes a time axis and a frequency axis and elements in the representation correspond to a value at a particular time and a particular frequency, embedding a watermark in the time frequency domain representation to produce a watermarked signal in the time frequency domain, and converting the watermarked signal from the time-frequency domain into a domain in which the signal is perceived by viewers or listeners.
Claim 5
Dependent Claim
37 words
The method of claim 2 wherein the embedding includes embedding using a perceptual model that identifies noisy areas in the time frequency representation and hides the watermark data around the noisy areas in the time frequency representation.
Claim 6
Dependent Claim
27 words
The method of claim 2 wherein the conversion to the time-frequency domain includes dividing the signal into blocks and separately transforming the blocks into the time-frequency domain.
Claim 7
Dependent Claim
20 words
The method of claim 4 wherein a watermark message comprising two or more message symbols is embedded into each block.
Claim 8
Dependent Claim
38 words
The method of claim 2 wherein a calibration signal is embedded in the media signal to assist a watermark decoder in determining scaling and alignment of the watermark in a potentially distorted version of the watermarked media signal.
Claim 9
Dependent Claim
23 words
The method of claim 6 wherein the calibration signal includes a signal with distinct impulse functions in the magnitude of the Fourier domain.
Claim 10
Dependent Claim
49 words
The method of claim 2 wherein the media signal is an audio signal, the audio signal is down-sampled before the watermark is embedded, the watermark is isolated as a time domain signal, and the isolated, time domain watermark is added to the original media signal in the time domain.
Claim 11
Dependent Claim
46 words
The method of claim 8 wherein the isolation of the watermark includes subtracting an unmarked version of the media signal from the watermarked version of the media signal in the time-frequency domain and subsequently converting the time-frequency representation of the watermark back into the time domain.
Claim 12
Dependent Claim
26 words
The method of claim 8 wherein the isolation of the watermark includes computing a time-frequency domain watermark signal from the time-frequency representation of the media signal.
Claim 13
Independent Claim
101 words
A method of watermarking a media signal comprising: transforming the media signal from a perceptual domain to a transform domain, computing a watermark signal from the transformed signal, isolating the watermark signal, and adding the watermark to the media signal in the perceptual domain; wherein transforming includes separating the media signal into blocks and converting each block into the time-frequency domain, and performing an inverse time-frequency transform when isolating the watermark signal, wherein the time-frequency domain includes a time axis and a frequency axis and elements in the domain correspond to a value at a particular time and a particular frequency.
Claim 14
Independent Claim
101 words
A method of watermarking a media signal comprising: transforming the media signal from a perceptual domain to a transform domain, computing a watermark signal from the transformed signal, isolating the watermark signal, and adding the watermark to the media signal in the perceptual domain; wherein transforming includes separating the media signal into blocks and converting each block into the time-frequency domain, and performing an inverse time-frequency transform when isolating the watermark signal, wherein the time-frequency domain includes a time axis and a frequency axis and elements in the domain correspond to a value at a particular time and a particular frequency.
Claim 15
Dependent Claim
33 words
The method of claim 11 wherein transforming includes down-sampling the media signal, and wherein isolating the watermark signal includes up-sampling the watermark signal before adding the upsampled watermark signal to the media signal.
Claim 16
Dependent Claim
43 words
The method of claim 11 wherein the time-frequency transform includes taking fast Fourier transforms of windowed segments of each block and the isolation of the watermark includes taking inverse Fourier transforms of each segment and adding the segments together in the perceptual domain.
References Cited (Backward Citations)
US4313197A
Cited
US4425661A
Cited
GB2196167A
Cited
US4963998A
Cited
US4939515A
Cited
US5113437A
Cited
US5161210A
Cited
US5787334A
Cited
US5319735A
Cited
US5450490A
Cited
US5404377A
Cited
US5646997A
Cited
US5774452A
Cited
US5636292A
Cited
US5636292C1
Cited
US5613004A
Cited
US5822360A
Cited
US5930369A
Cited
US5687191A
Cited
US5905800A
Cited
US5822432A
Cited
US5828325A
Cited
US5893067A
Cited
US5933798A
Cited
US6061793A
Cited
US5915027A
Cited
US6078664A
Cited
US6185312B1
Cited
US5940135A
Cited
WO1998053565A1
Cited
US6208735B1
Cited
US5945932A
Cited
US6205249B1
Cited
US6233347B1
Cited
WO2000000969A1
Cited
US20020006203A1
Cited
US6512837B1
Cited
US6483927B2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-01-05 | 2007-07-07 | 2008-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-01-05 | 2011-07-07 | 2012-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-01-05 | 2015-07-07 | 2016-01-06 | $7700.00 | Window Closed / Lapsed |