US6408103B1
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Method for preserving spatial detail and color content when adjusting the tone scale of a digital color image
Assignee: Monument Peak Ventures LLC
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Filing: 1998-12-31
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Granted: 2002-06-18
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Expires: 2018-12-31
Abstract
Abstract A method for preserving spatial detail and color content is performed when adjusting the tone scale of a digital color image. This method comprises the steps of receiving a digital color image, providing a tone scale function for adjusting the tone scale of the digital color image; providing a spatial filter for adjusting the tone scale of the digital color image; transforming the digital color image into a luminance signal and chrominance signals; using the tone scale function, the spatial filter, and the luminance signal to produce an enhanced luminance signal; and using the tone scale function, the spatial filter, the luminance signal, and the chrominance signals to produce enhanced chrominance signals.
Inventors
- 👤 Andrew C. Gallagher
- 👤 Edward B. Gindele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:35
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6027; H04N5/00; H04N5/14; H04N5/20
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
123 words
A method for preserving spatial detail and color content when adjusting tone scale of a digital color image, the method comprising: (a) providing a tone scale function for adjusting the tone scale of the digital color image; (b) providing a spatial filter for adjusting the tone scale of the digital color image; (c) transforming the digital color image into a luminance signal and chrominance signals; (d) using the tone scale function, the spatial filter, and the luminance signal to produce an enhanced luminance signal; (e) using the tone scale function, the spatial filter, the luminance signal, and the chrominance signals to produce enhanced chrominance signals; and (f) producing an enhanced digital color image from the enhanced luminance signal and the enhanced chrominance signals.
Claim 2
Independent Claim
123 words
A method for preserving spatial detail and color content when adjusting tone scale of a digital color image, the method comprising: (a) providing a tone scale function for adjusting the tone scale of the digital color image; (b) providing a spatial filter for adjusting the tone scale of the digital color image; (c) transforming the digital color image into a luminance signal and chrominance signals; (d) using the tone scale function, the spatial filter, and the luminance signal to produce an enhanced luminance signal; (e) using the tone scale function, the spatial filter, the luminance signal, and the chrominance signals to produce enhanced chrominance signals; and (f) producing an enhanced digital color image from the enhanced luminance signal and the enhanced chrominance signals.
Claim 3
Dependent Claim
24 words
The method as in claim 1 wherein step (d) further includes creating a control signal from a spatially filtered version of the luminance signal.
Claim 4
Dependent Claim
54 words
The method as in claim 2 , wherein step (d) further includes generating a high pass and a low pass signal; wherein step (d) includes generating at least two non-linear spatial filtered versions of the digital image channel from the high pass signal, the low pass signal, the control signal, and the luminance signal.
Claim 5
Dependent Claim
38 words
The method as in claim 3 , wherein step (d) further includes generating an enhanced luminance signal by the application of the tone scale function to one of the non-linear spatial filtered signal versions of the luminance signal.
Claim 6
Dependent Claim
46 words
The method as in claim 4 , wherein step (d) further includes generating an enhanced luminance signal by the application of the tone scale function to one of the non-linear spatial filtered signal versions of the luminance signal, and modifying the remaining non-linear spatial filtered signal.
Claim 7
Dependent Claim
24 words
The method as in claim 5 wherein step (e) further includes calculating a chrominance adjustment factor based on the size of the spatial filter.
Claim 8
Dependent Claim
20 words
The method as in claim 6 wherein step (e) further includes calculating a local slope of the tone scale function.
Claim 9
Dependent Claim
17 words
The method as in claim 7 wherein step (e) further includes calculating a color position weight factor.
Claim 10
Dependent Claim
24 words
The method as in claim 1 wherein step (e) further includes calculating a chrominance adjustment factor based on the size of the spatial filter.
Claim 11
Dependent Claim
20 words
The method as in claim 9 wherein step (e) further includes calculating a local slope of the tone scale function.
Claim 12
Dependent Claim
17 words
The method as in claim 10 wherein step (e) further includes calculating a color position weight factor.
Claim 13
Independent Claim
119 words
A method for preserving spatial detail and color content when adjusting tone scale of a digital color image, the method comprising: a) providing a tone scale function for adjusting the tone scale of the digital color image; b) providing a spatial filter for adjusting the tone scale of the digital color image; c) transforming the digital color image into a luminance and chrominance signals; d) using the tone scale function, the spatial filter, and the luminance signal to produce an enhanced luminance signal; e) calculating a local slope of the tone scale function; f) calculating a chrominance adjustment factor based on the local slope; and g) producing enhanced chrominance signals from the chrominance signals and the chrominance adjustment factor.
Claim 14
Independent Claim
119 words
A method for preserving spatial detail and color content when adjusting tone scale of a digital color image, the method comprising: a) providing a tone scale function for adjusting the tone scale of the digital color image; b) providing a spatial filter for adjusting the tone scale of the digital color image; c) transforming the digital color image into a luminance and chrominance signals; d) using the tone scale function, the spatial filter, and the luminance signal to produce an enhanced luminance signal; e) calculating a local slope of the tone scale function; f) calculating a chrominance adjustment factor based on the local slope; and g) producing enhanced chrominance signals from the chrominance signals and the chrominance adjustment factor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2005-06-17 | 2005-12-17 | 2006-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-06-17 | 2009-12-17 | 2010-06-18 | $3760.00 | Window Closed / Lapsed |
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