US5680327A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and process for a digital swatchbook
Assignee: OTP Inc
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Filing: 1995-03-21
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Granted: 1997-10-21
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Expires: 2015-03-21
Abstract
Abstract The present invention provides a method and apparatus for accurately matching colors. The color matching system includes a host computer and a color input device in communication with the host computer. Preferably the color input device is capable of obtaining spectral data, such as that obtained using a spectrophotometer. The host computer includes a color library, a color management system, a monitor, and a user interface. In one aspect of the invention, the user selects a target color, a color library to use for matching, a color distance tolerance, and a light source under which the colors are to be matched. The target color is compared to the colors in the library and the color or colors in the library that are within the specified color tolerance are reported. In a second aspect of the invention, the user selects a color and two illuminants. The color under each of the two illuminants is compared and the color distance between the two is reported. In a third aspect of the invention, a selected color is transformed to the color space of a designated printer and then back-transformed to the color space of the monitor and displayed. The displayed color represents a simulation of the selected color as it would appear if printed.
Inventors
- 👤 Robert L. Cook
- 👤 Eric M. Herrmann
- 👤 Nelson Offner
- 👤 Edward M. Granger
- 👤 Akin Dirik
- 👤 Lawrence D. Baca
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:13
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/46; G01J3/462; G01J3/463; G01J3/465; G01J2003/466
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
116 words
In an appropriately programmed digital computer, a method of displaying a color under different lighting conditions, said method comprising the steps of: acquiring a first set of spectral data representative of a target color; acquiring a second set of spectral data representative of a first illuminant; acquiring a third set of spectral data representative of a second illuminant; determining a first intensity spectrum from said first and second sets of spectral data; determining a second intensity spectrum from said first and third sets of spectral data; converting said first and second intensity spectra to a first and a second set of RGB values; and displaying said first and second sets of RGB values on a monitor.
Claim 2
Dependent Claim
116 words
In an appropriately programmed digital computer, a method of displaying a color under different lighting conditions, said method comprising the steps of: acquiring a first set of spectral data representative of a target color; acquiring a second set of spectral data representative of a first illuminant; acquiring a third set of spectral data representative of a second illuminant; determining a first intensity spectrum from said first and second sets of spectral data; determining a second intensity spectrum from said first and third sets of spectral data; converting said first and second intensity spectra to a first and a second set of RGB values; and displaying said first and second sets of RGB values on a monitor.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein said first set of spectral data is a reflectance spectrum.
Claim 4
Dependent Claim
49 words
The method of claim 1, further comprising the step of converting said first and second intensity spectra to a first and a second set of CIE XYZ values, said first and second sets of CIE XYZ values subsequently used to calculate said first and second sets of RGB values.
Claim 5
Dependent Claim
34 words
The method of claim 3, wherein said conversion from said first and second sets of CIE XYZ values to said first and second sets of RGB values is performed using a Von Kries adaptation.
Claim 6
Dependent Claim
35 words
The method of claim 3, further comprising the steps of: computing a color difference between said first and second sets of CIE XYZ values; and displaying a representation of said color difference on said monitor.
Claim 7
Dependent Claim
129 words
A digital computer system for displaying a color under different lighting conditions, comprising: a color sampling device for generating a reflectance spectral representation of a selected target color; a light sampling device for generating an intensity spectral representation of a first and a second illuminant; a writable non-volatile memory for storing said spectral representations of said target color and said first and second illuminants; means for multiplying said reflectance spectrum by said first illuminant spectrum to produce a first reflected intensity spectrum; means for multiplying said reflectance spectrum by said second illuminant spectrum to produce a second reflected intensity spectrum; means for converting said first and second reflected intensity spectra to RGB values; and a display for displaying the RGB values of said first and second reflected intensity spectra.
Claim 8
Dependent Claim
129 words
A digital computer system for displaying a color under different lighting conditions, comprising: a color sampling device for generating a reflectance spectral representation of a selected target color; a light sampling device for generating an intensity spectral representation of a first and a second illuminant; a writable non-volatile memory for storing said spectral representations of said target color and said first and second illuminants; means for multiplying said reflectance spectrum by said first illuminant spectrum to produce a first reflected intensity spectrum; means for multiplying said reflectance spectrum by said second illuminant spectrum to produce a second reflected intensity spectrum; means for converting said first and second reflected intensity spectra to RGB values; and a display for displaying the RGB values of said first and second reflected intensity spectra.
Claim 9
Dependent Claim
110 words
In an appropriately programmed digital computer, a method of matching colors comprising the steps of: acquiring a digital representation of a target color; choosing a color difference tolerance; computing a color difference between said target color and each color of a color library; comparing said color difference for each color of said color library to said color difference tolerance; providing each color of said color library in which said color difference between said color and said target color is less than said color difference tolerance; and providing a total number of colors in which the difference between said color and said target color is less than said color difference tolerance.
Claim 10
Dependent Claim
110 words
In an appropriately programmed digital computer, a method of matching colors comprising the steps of: acquiring a digital representation of a target color; choosing a color difference tolerance; computing a color difference between said target color and each color of a color library; comparing said color difference for each color of said color library to said color difference tolerance; providing each color of said color library in which said color difference between said color and said target color is less than said color difference tolerance; and providing a total number of colors in which the difference between said color and said target color is less than said color difference tolerance.
Claim 11
Dependent Claim
149 words
In an appropriately programmed digital computer, a method of matching colors comprising the steps of: acquiring a digital representation of a target color; choosing a color difference tolerance; selecting a first illuminant; converting all colors within a color library and said target color to a first tristimulus color space based on said first illuminant; selecting a second illuminant; converting all colors within said color library and said target color from said first tristimulus color space to a second tristimulus color space, said second tristimulus color space based on said second illuminant; computing a color difference between said target color and each color of said color library; comparing said color difference for each color of said color library to said color difference tolerance; and providing each color of said color library in which said color difference between said color and said target color is less than said color difference tolerance.
Claim 12
Dependent Claim
149 words
In an appropriately programmed digital computer, a method of matching colors comprising the steps of: acquiring a digital representation of a target color; choosing a color difference tolerance; selecting a first illuminant; converting all colors within a color library and said target color to a first tristimulus color space based on said first illuminant; selecting a second illuminant; converting all colors within said color library and said target color from said first tristimulus color space to a second tristimulus color space, said second tristimulus color space based on said second illuminant; computing a color difference between said target color and each color of said color library; comparing said color difference for each color of said color library to said color difference tolerance; and providing each color of said color library in which said color difference between said color and said target color is less than said color difference tolerance.
Claim 13
Dependent Claim
149 words
In an appropriately programmed digital computer, a method of matching colors comprising the steps of: acquiring a digital representation of a target color, wherein said target color and each color of a color library is in the form of reflectance data; choosing a color difference tolerance; selecting an illuminant spectra; adjusting said reflectance data for said target color and for each color of said color library to account for said illuminant spectra to produce a plurality of intensity spectra; converting each of said intensity spectra to a CIE XYZ color space; computing a color difference between said target color and each color of said color library; comparing said color difference for each color of said color library to said color difference tolerance; and providing each color of said color library in which said color difference between said color and said target color is less than said color difference tolerance.
Claim 14
Dependent Claim
149 words
In an appropriately programmed digital computer, a method of matching colors comprising the steps of: acquiring a digital representation of a target color, wherein said target color and each color of a color library is in the form of reflectance data; choosing a color difference tolerance; selecting an illuminant spectra; adjusting said reflectance data for said target color and for each color of said color library to account for said illuminant spectra to produce a plurality of intensity spectra; converting each of said intensity spectra to a CIE XYZ color space; computing a color difference between said target color and each color of said color library; comparing said color difference for each color of said color library to said color difference tolerance; and providing each color of said color library in which said color difference between said color and said target color is less than said color difference tolerance.
Claim 15
Dependent Claim
17 words
The method of claim 9, wherein said illuminant spectrum is selected from a plurality of illuminant spectra.
Claim 16
Dependent Claim
14 words
The method of claim 9, wherein said illuminant spectrum is measured using a spectrophotometer.
Claim 17
Dependent Claim
14 words
The method of claim 9, wherein said illuminant spectrum is measured using a colorimeter.
References Cited (Backward Citations)
US2774276A
Cited
US3159742A
Cited
US3504980A
Cited
US4110826A
Cited
US4414635A
Cited
US4954972A
Cited
US5221959A
Cited
US5459530A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-20 | 2001-04-21 | 2001-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-20 | 2005-04-21 | 2005-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-20 | 2009-04-21 | 2009-10-21 | $7700.00 | Window Closed / Lapsed |