US5530759A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color correct digital watermarking of images
Assignee: International Business Machines Corp
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Filing: 1995-02-01
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Granted: 1996-06-25
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Expires: 2015-02-01
Abstract
Abstract A system for placing a visible "watermark" on a digital image is disclosed, wherein an image of the watermark is combined with the digital image. The pixels of the watermark image are examined, and for each pixel whose value is not a specified "transparent" value, the corresponding pixel of the original image is modified by changing its brightness but its chromaticities. This results in a visible mark which allows the contents of the image to be viewed clearly, but which discourages unauthorized use of the image.
Inventors
- 👤 Gordon W. Braudaway
- 👤 Karen A. Magerlein
- 👤 Frederick C. Mintzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:41
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/913; G; G06; G06T; G06T1/00; G06T1/0021; G06T1/0028; G06T11/00; H04N1/00; H04N1/32; H04N1/32101; H04N1/32144; H04N1/32149; H04N1/32203; H04N1/32208; H04N1/32251; H04N1/32309; H04N1/3232; H04N1/32325; H04N1/46; H04N21/00; H04N21/20; H04N21/23; H04N21/238; H04N21/2389; H04N21/23892; H04N21/80; H04N21/83; H04N21/835; H04N21/8358; G06T2201/00; G06T2201/005; G06T2201/0051; H04N1/00838; H04N2005/91307; H04N2005/91335; H04N2201/00; H04N2201/32; H04N2201/3201; H04N2201/3225; H04N2201/3233
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
51 words
A method of placing a visible watermark on a digital image, comprising the steps of: providing a digital original image; providing a digital watermark image; and, producing a watermarked image by superimposing the watermark image on the original image without changing the chromaticities of pixels of the original image as watermarked.
Claim 2
Independent Claim
51 words
A method of placing a visible watermark on a digital image, comprising the steps of: providing a digital original image; providing a digital watermark image; and, producing a watermarked image by superimposing the watermark image on the original image without changing the chromaticities of pixels of the original image as watermarked.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein the producing comprises the steps of: for each pixel in the watermark image that is not "transparent", modifying the corresponding pixel of the original image by changing the brightness but not the color.
Claim 4
Independent Claim
49 words
A method of applying a digital watermark to an original image comprising the step of applying the watermark to the original image as a multiplicative correction on pixel sample values of the original image in a linear color space such that the chromaticities of the pixels are not changed.
Claim 5
Independent Claim
49 words
A method of applying a digital watermark to an original image comprising the step of applying the watermark to the original image as a multiplicative correction on pixel sample values of the original image in a linear color space such that the chromaticities of the pixels are not changed.
Claim 6
Independent Claim
51 words
A system for placing a visible watermark on a digital image, comprising: a storage device having a digital original image and a digital watermark stored therein; and, means for producing a watermarked image by superimposing the watermark on the original image without changing the chromaticities of the original image as watermarked.
Claim 7
Independent Claim
51 words
A system for placing a visible watermark on a digital image, comprising: a storage device having a digital original image and a digital watermark stored therein; and, means for producing a watermarked image by superimposing the watermark on the original image without changing the chromaticities of the original image as watermarked.
Claim 8
Dependent Claim
34 words
The system of claim 4 wherein the means for producing comprises: means for modifying each pixel of the original image corresponding to a non-transparent watermark pixel, by changing the brightness but not the color.
Claim 9
Independent Claim
85 words
A system for applying a digital watermark to an original digital image, comprising: means for identifying a subset of pixels of the original image that will be modified as a result of applying the watermark; means for determining a scaling value based on the values of the color components for each of the pixels in the subset, means of multiplying each of the color components of each of the pixels in the subset by its scaling value, and means for storing a resulting watermarked image.
Claim 10
Independent Claim
85 words
A system for applying a digital watermark to an original digital image, comprising: means for identifying a subset of pixels of the original image that will be modified as a result of applying the watermark; means for determining a scaling value based on the values of the color components for each of the pixels in the subset, means of multiplying each of the color components of each of the pixels in the subset by its scaling value, and means for storing a resulting watermarked image.
Claim 11
Independent Claim
103 words
A system for applying a digital watermark to an original digital image, comprising: means for identifying a subset of pixels of the original image to be modified as a result of applying the watermark; means for linearizing the color components of each pixel in the subset, means for determining a scaling value based on the linearized values of the color components for each pixel in the subset, means of multiplying each component of each pixel in the subset by its scaling value, and means for delinearizing the modified components of each pixel in the subset, and means for storing a resulting watermarked image.
Claim 12
Independent Claim
103 words
A system for applying a digital watermark to an original digital image, comprising: means for identifying a subset of pixels of the original image to be modified as a result of applying the watermark; means for linearizing the color components of each pixel in the subset, means for determining a scaling value based on the linearized values of the color components for each pixel in the subset, means of multiplying each component of each pixel in the subset by its scaling value, and means for delinearizing the modified components of each pixel in the subset, and means for storing a resulting watermarked image.
Claim 13
Dependent Claim
21 words
The system of claim 7 wherein said means for determining a scaling value S is responsive to a random noise field.
Claim 14
Dependent Claim
33 words
The system of claim 7, wherein said means for determining a scaling value S is responsive to an element of a reproducible random sequence, or a noise sequence created by a ciphered key.
Claim 15
Dependent Claim
24 words
The system of claim 7 wherein said means for determining a scaling value S is responsive to the value of a corresponding watermark pixel.
Claim 16
Independent Claim
69 words
A method for applying a digital watermark to an original digital image, comprising the steps of: identifying a subset of pixels of the original image to be modified; for each pixel in said subset of pixels, determining a scaling value based on the values of the color components of said pixel; and, multiplying each component of said pixel by said scaling value S, and, storing a resulting watermarked image.
Claim 17
Independent Claim
69 words
A method for applying a digital watermark to an original digital image, comprising the steps of: identifying a subset of pixels of the original image to be modified; for each pixel in said subset of pixels, determining a scaling value based on the values of the color components of said pixel; and, multiplying each component of said pixel by said scaling value S, and, storing a resulting watermarked image.
Claim 18
Dependent Claim
32 words
The method of claim 11 comprising the further steps of: prior to the determining, linearizing the color components of said pixel; and, subsequent to the multiplying, delinearizing modified components of said pixel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-06-25 | 1999-12-25 | 2000-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-25 | 2003-12-25 | 2004-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-25 | 2007-12-25 | 2008-06-25 | $7700.00 | Window Closed / Lapsed |