Patent US6850342B2 successfully refreshed from Google Patents.
US6850342B2
Expired / Lapsed
US
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Color transform method for preferential gamut mapping of colors in images
Assignee: Monument Peak Ventures LLC
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Filing: 2002-12-06
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Granted: 2005-02-01
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Expires: 2022-12-06
Abstract
Abstract A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut includes the steps of: transforming the color values of the first color space to color values in an intermediate color space; specifying one or more predefined color regions in an intermediate color space; preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and transforming the modified color values to code values for driving the output device.
Inventors
- 👤 Geoffrey J. Woolfe
- 👤 Robert E. Cookingham
- 👤 John R. D'Errico
- 👤 Jonathan B. Phillips
- 👤 Karin Topfer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:32
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/62
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
151 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space; c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color value to fit the second color gamut using one or more color magnets while shielding the predefined color regions using shielding color magnets to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
Claim 2
Independent Claim
151 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space; c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color value to fit the second color gamut using one or more color magnets while shielding the predefined color regions using shielding color magnets to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
Claim 3
Dependent Claim
19 words
The method claimed in claim 1 , wherein the intermediate color space is an approximately perceptually uniform color space.
Claim 4
Dependent Claim
14 words
The method claimed in claim 2 , wherein the intermediate color space is CIELAB.
Claim 5
Dependent Claim
31 words
The method claimed in claim 1 , wherein the transform for converting the digital color image signal to code values is expressed as one or a succession of multidimensional lookup tables.
Claim 6
Dependent Claim
33 words
The method claimed in claim 1 , wherein the transform for converting the digital color image signal to code values is expressed as an ICC profile or a concatenation of several ICC profiles.
Claim 7
Dependent Claim
24 words
The method claimed in claim 1 , wherein the predefined color regions are skin tone and other natural colors such as sand and bark.
Claim 8
Dependent Claim
82 words
The method claimed in claim 6 where the center of the skin tone region is placed at CIELAB chroma, C ab *, values between 10 and 30, a*/b* hue angles, h ab *, between 40 and 50 degrees and any lightness, L*, value between 1 and 100, while the overall size of the color region, defined as distance from minimum to maximum, shielded around the center falls between 20 and 60 C ab * units and 20 to 70 ab * units.
Claim 9
Dependent Claim
18 words
The method claimed in claim 1 , wherein the predefined color region includes neutral and near neutral colors.
Claim 10
Dependent Claim
73 words
The method claimed in claim 8 , where the center of the neutral region is placed at CIELAB chroma, C ab *, values between 0 and 5, and any a*/b* hue angle, h ab *, and lightness value, L*, while the overall size of the color region, defined as distance from minimum to maximum, shielded around the center falls between 10 and 20 C ab * units, encompassing all hue and lightness values.
Claim 11
Dependent Claim
15 words
The method claimed in claim 1 , wherein the predefined color regions are trademark colors.
Claim 12
Dependent Claim
45 words
The method claimed in claim 1 , where the mapping of colors in the intermediate color space outside the predetermined color regions is such that the initial CIELAB chroma values, Cab* in the intermediate color space are increased by a factor of 1.1 to 1.6.
Claim 13
Dependent Claim
22 words
The method claimed in claim 1 , where step c) is implemented as an abstract ICC profile in ICC Profile Connection space.
Claim 14
Dependent Claim
15 words
The method claimed in claim 1 , wherein the output device is an inkjet printer.
Claim 15
Dependent Claim
31 words
The method claimed in claim 5 , wherein the intermediate color space is CIELAB and the predefined color regions are skin tone and other natural colors such as sand and bark.
Claim 16
Independent Claim
222 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space wherein the predefined color regions include skin tone at CIELAB chroma, C ab *, values between 10 and 30, a*/b* hue angles, h ab *, between 40 and 50 degrees and any lightness, L*, value between 1 and 100, while the overall size of the color region, defined as distance from minimum to maximum, shielded around the center falls between 20 and 60 C ab * units and 20 to 70 h ab * units. c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
Claim 17
Independent Claim
222 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space wherein the predefined color regions include skin tone at CIELAB chroma, C ab *, values between 10 and 30, a*/b* hue angles, h ab *, between 40 and 50 degrees and any lightness, L*, value between 1 and 100, while the overall size of the color region, defined as distance from minimum to maximum, shielded around the center falls between 20 and 60 C ab * units and 20 to 70 h ab * units. c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
Claim 18
Independent Claim
216 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space wherein one predefined color region includes neutral and near neutral colors centered at CIELAB chroma, C ab *, values between 0 and 5, and any a*/b* hue angle, h ab *, and lightness value, L*, while the overall size of the color region, defined as distance from minimum to maximum, shielded around the center falls between 10 and 20 C ab * units, encompassing all hue and lightness values; c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
Claim 19
Independent Claim
216 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space wherein one predefined color region includes neutral and near neutral colors centered at CIELAB chroma, C ab *, values between 0 and 5, and any a*/b* hue angle, h ab *, and lightness value, L*, while the overall size of the color region, defined as distance from minimum to maximum, shielded around the center falls between 10 and 20 C ab * units, encompassing all hue and lightness values; c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
Claim 20
Independent Claim
169 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space; c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut such that the initial CIELAB chroma values, Cab* in the intermediate color space are increased by a factor of 1.1 to 1.6. while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
Claim 21
Independent Claim
169 words
A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut, comprising the steps of: a) transforming the color values of the first color space to color values in an intermediate color space; b) specifying one or more predefined color regions in an intermediate color space; c) preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut such that the initial CIELAB chroma values, Cab* in the intermediate color space are increased by a factor of 1.1 to 1.6. while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and d) transforming the modified color values to code values for driving the output device.
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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) | 2008-02-01 | 2008-08-02 | 2009-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-02-01 | 2012-08-02 | 2013-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-02-01 | 2016-08-02 | 2017-02-01 | $7700.00 | Window Closed / Lapsed |