US6556689B1
Expired / Lapsed
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Watermarking methods for digital images and videos
Assignee: University of Delaware
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Filing: 1999-04-20
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Granted: 2003-04-29
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Expires: 2019-04-20
Abstract
Abstract The present invention relates to multiresolution watermarking methods for digital images which are based on a discrete wavelet transform (DWT). Pseudo-random codes are added to the large coefficients located at the high and middle frequency bands of the DWT of a digital image. A peak is detected to signify a signature of the watermark. The methods taught herein are more robust then conventional methods for common image distortions, such as the wavelet transform based image compression, additive noise, image halftoning, and image resealing. Moreover, the method is hierarchal. The computational load needed to detect the watermark depends on the noise level in an image. The multiresolution and hierarchial watermarking method taught by the present invention results in lower computational loads, on average, while providing a high quality watermark which is utilizable with modern image/video compression standards.
Inventors
- 👤 Xiang-Gen Xia
- 👤 Charles Boncelet, Jr.
- 👤 Gonzalo R. Arce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:30
CPC Classifications
G; G06; G06T; G06T1/00; G06T1/0021; G06T1/005; G06T1/0057; G06T2201/00; G06T2201/005; G06T2201/0052; G06T2201/0081
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
75 words
A method of multiresolution watermarking for digital images, the method comprising the steps of: a) adding pseudo-random sequences to large coefficients positioned at high and middle frequency bands of a discrete wavelet transform of the digital image; b) taking the inverse discrete wavelet transform of the discrete wavelet transform of the digital image having added pseudo-random sequences to produce a watermarked image; and c) detecting a peak to signify a signature of the watermarked image.
Claim 2
Independent Claim
75 words
A method of multiresolution watermarking for digital images, the method comprising the steps of: a) adding pseudo-random sequences to large coefficients positioned at high and middle frequency bands of a discrete wavelet transform of the digital image; b) taking the inverse discrete wavelet transform of the discrete wavelet transform of the digital image having added pseudo-random sequences to produce a watermarked image; and c) detecting a peak to signify a signature of the watermarked image.
Claim 3
Independent Claim
181 words
A method of multiresolution watermarking for digital images, the method comprising the steps of encoding and decoding the digital image in a discrete wavelet transform, wherein the encoding steps comprise: a) decomposing the digital image into a multiplicity of bands having a pyramidal structure; b) adding pseudo-random sequences to large coefficients located at high and middle frequency bands of the discrete wavelet transform; and c) taking the inverse discrete wavelet transform of the discrete wavelet transform having added pseudo-random sequences to produce a watermarked image; and wherein the decoding steps comprise: d) decomposing the watermarked image and the original digital image into at least four bands; and e) calculating cross correlations of the bands of the watermarked and original digital images until a peak is detected; or if no peak is detected, f) decomposing the watermarked and original digital images into four additional subbands and repeating step e) until a peak is detected, wherein the detection of the peak signifies a signature of the watermarked image and the failure to detect the peak signifies an undetectable signature of the watermarked image.
Claim 4
Independent Claim
181 words
A method of multiresolution watermarking for digital images, the method comprising the steps of encoding and decoding the digital image in a discrete wavelet transform, wherein the encoding steps comprise: a) decomposing the digital image into a multiplicity of bands having a pyramidal structure; b) adding pseudo-random sequences to large coefficients located at high and middle frequency bands of the discrete wavelet transform; and c) taking the inverse discrete wavelet transform of the discrete wavelet transform having added pseudo-random sequences to produce a watermarked image; and wherein the decoding steps comprise: d) decomposing the watermarked image and the original digital image into at least four bands; and e) calculating cross correlations of the bands of the watermarked and original digital images until a peak is detected; or if no peak is detected, f) decomposing the watermarked and original digital images into four additional subbands and repeating step e) until a peak is detected, wherein the detection of the peak signifies a signature of the watermarked image and the failure to detect the peak signifies an undetectable signature of the watermarked image.
Claim 5
Dependent Claim
13 words
The method according to claim 2 , wherein the decoding steps are hierarchical.
Claim 6
Dependent Claim
28 words
The method according to claim 2 , wherein the four bands in step d) comprise a low-low band, a low-high band, a high-low band, and a high-high band.
Claim 7
Dependent Claim
16 words
The method according to claim 2 , wherein the discrete wavelet transform includes Haar wavelet filters.
Claim 8
Dependent Claim
15 words
The method according to claim 2 , wherein the watermarking includes embedded zero-tree wavelet coding.
Claim 9
Dependent Claim
33 words
The method according to claim 2 , wherein the digital image is pyramidally decomposed and distorted, the distortions being selected from the group consisting of additive noise, image compression, halftoning, and image scaling.
Claim 10
Dependent Claim
12 words
A watermark image produced by the method according to claim 2 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-04-28 | 2006-10-28 | 2007-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-04-28 | 2010-10-28 | 2011-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-04-28 | 2014-10-28 | 2015-04-29 | $7700.00 | Window Closed / Lapsed |