US5363318A
Expired / Lapsed
US
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Method and apparatus for adaptive color characterization and calibration
Assignee: Eastman Kodak Co
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Filing: 1992-03-23
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Granted: 1994-11-08
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Expires: 2012-03-23
Abstract
Abstract A system and a method in which channel independent linear transfer functions or calibration curves for color devices such as printers, scanners and displays are individually created. The calibration curves are created using a low cost light intensity sensor. Scaling constants are determined and desired linear aim response curves are scaled together to maintain a desired color balance. The color saturation effects are also removed by scaling or normalizing to some maximum input drive level that does not saturate any of the colors. The characterization curves are rotated about the desired linear aim response curves to create compensation curves for each the characterization curves adapted to the particular device response characteristics. The dynamic range maximized, linearized, color balanced and saturation compensation curves are loaded into conversion tables which convert input values into the appropriate output values.
Inventors
- 👤 David K. McCauley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:10
CPC Classifications
H; H04; H04N; H04N17/00; H04N17/04; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6027; H04N1/603; H04N1/6033
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
116 words
A method of calibrating a desk top computer color device, comprising the steps of: (a) controlling, upon initiation of a user, the color device to produce three color characterization curves of a tricolor response of the color device; and (b) adaptively producing three color balanced calibration tables from the characterization curves, comprising the steps of: (b1) determining scaling constants; (b2) normalizing the characterization curves for a maximum device dynamic range compensating for saturation; (b3) determining a most negative normalized response; (b4) determining color balance constants from the most negative normalized response; (b5) scaling aim curves using the color balance constants; and (b6) creating the calibration tables using the scaled aim curves and the normalized characterization curves.
Claim 2
Independent Claim
116 words
A method of calibrating a desk top computer color device, comprising the steps of: (a) controlling, upon initiation of a user, the color device to produce three color characterization curves of a tricolor response of the color device; and (b) adaptively producing three color balanced calibration tables from the characterization curves, comprising the steps of: (b1) determining scaling constants; (b2) normalizing the characterization curves for a maximum device dynamic range compensating for saturation; (b3) determining a most negative normalized response; (b4) determining color balance constants from the most negative normalized response; (b5) scaling aim curves using the color balance constants; and (b6) creating the calibration tables using the scaled aim curves and the normalized characterization curves.
Claim 3
Independent Claim
107 words
A method of calibrating a desk top computer color device, comprising the steps of: (a) controlling the color device to produce color characterization curves of a color response of the device; and (b) adaptively producing color balanced calibration tables from the characterization curves, step (b) comprising: (b1) determining scaling constants; (b2) normalizing the characterization curves for a maximum device dynamic range compensating for saturation; (b3) determining a most negative normalized response; (b4) determining color balance constants from the most negative normalized response; (b5) scaling aim curves using the color balance constants; and (b6) creating the calibration tables using the scaled aim curves and the normalized characterization curves.
Claim 4
Independent Claim
107 words
A method of calibrating a desk top computer color device, comprising the steps of: (a) controlling the color device to produce color characterization curves of a color response of the device; and (b) adaptively producing color balanced calibration tables from the characterization curves, step (b) comprising: (b1) determining scaling constants; (b2) normalizing the characterization curves for a maximum device dynamic range compensating for saturation; (b3) determining a most negative normalized response; (b4) determining color balance constants from the most negative normalized response; (b5) scaling aim curves using the color balance constants; and (b6) creating the calibration tables using the scaled aim curves and the normalized characterization curves.
Claim 5
Independent Claim
46 words
A method of calibrating a desk top computer color device, comprising the steps of: (a) controlling the color device to produce color transfer characterization curves of a color response of the device; and (b) adaptively producing white point color balanced calibration tables from the characterization curves.
Claim 6
Independent Claim
46 words
A method of calibrating a desk top computer color device, comprising the steps of: (a) controlling the color device to produce color transfer characterization curves of a color response of the device; and (b) adaptively producing white point color balanced calibration tables from the characterization curves.
Claim 7
Dependent Claim
20 words
A method as recited in claim 3, wherein said method is initiated by a user of the desk top computer.
Claim 8
Dependent Claim
22 words
A method as recited in claim 3, wherein said characterization curves of step (a) are first, second and third different color curves.
Claim 9
Dependent Claim
26 words
A method as recited in claim 3, wherein step (b) comprises producing the white point color balanced calibration tables using a color balanced tricolor aim curve.
Claim 10
Dependent Claim
27 words
A method as recited in claim 3, wherein step (a) includes producing an RMS average for a group of pixels for each point on the characterization curves.
Claim 11
Independent Claim
56 words
A method of creating one dimensional color calibration tables from response characterization values produced by a color input/output device, comprising the steps of: (a) normalizing the characterization values; (b) determining white point color balanced aim curves from the characterization values; and (c) producing the color calibration tables using the balanced aim curves and the characterization values.
Claim 12
Independent Claim
56 words
A method of creating one dimensional color calibration tables from response characterization values produced by a color input/output device, comprising the steps of: (a) normalizing the characterization values; (b) determining white point color balanced aim curves from the characterization values; and (c) producing the color calibration tables using the balanced aim curves and the characterization values.
Claim 13
Dependent Claim
27 words
A method as recited in claim 8, further comprising (d) compensating for saturated channel response by scaling the balanced aim curves to preserve white point color balance.
Claim 14
Dependent Claim
14 words
A method as recited in claim 8, wherein the balanced aim curves are linear.
Claim 15
Dependent Claim
14 words
A method as recited in claim 8, wherein the balanced aim curves are nonlinear.
Claim 16
Independent Claim
114 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity characterization curves of color channels of the color device; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves, said calibration means comprising: constant means for determining normalized color balanced scaling constants; normalization means for normalizing the characterization curves to a maximum response; balance constant means for determining curve balance constants using the scaling constants; balance curve scaling means for scaling aim curves with the curve balance constants; and balanced curve creation means for creating correction tables by transforming the characterization curves using the scaled aim curves.
Claim 17
Independent Claim
114 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity characterization curves of color channels of the color device; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves, said calibration means comprising: constant means for determining normalized color balanced scaling constants; normalization means for normalizing the characterization curves to a maximum response; balance constant means for determining curve balance constants using the scaling constants; balance curve scaling means for scaling aim curves with the curve balance constants; and balanced curve creation means for creating correction tables by transforming the characterization curves using the scaled aim curves.
Claim 18
Independent Claim
126 words
An apparatus for calibrating a color device, the color device comprising a monitor, printer and scanner, the apparatus comprising: an achromatic light sensor separately and achromatically measuring intensity characterization curves of color channels of the color device; and a computer creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves, said computer comprising: constant means for determining normalized color balanced scaling constants; normalization means for normalizing the characterization curves to a maximum response; balance constant means for determining curve balance constants using the scaling constants; balance curve scaling means for scaling aim curves with the curve balance constants; and balanced curve creation means for creating correction tables by transforming the characterization curves using the scaled aim curves.
Claim 19
Independent Claim
126 words
An apparatus for calibrating a color device, the color device comprising a monitor, printer and scanner, the apparatus comprising: an achromatic light sensor separately and achromatically measuring intensity characterization curves of color channels of the color device; and a computer creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves, said computer comprising: constant means for determining normalized color balanced scaling constants; normalization means for normalizing the characterization curves to a maximum response; balance constant means for determining curve balance constants using the scaling constants; balance curve scaling means for scaling aim curves with the curve balance constants; and balanced curve creation means for creating correction tables by transforming the characterization curves using the scaled aim curves.
Claim 20
Independent Claim
65 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity characterization curves of color channels of the color device; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves and normalizing to a characterization curve having a most negative maximum response when compared to a corresponding aim curve.
Claim 21
Independent Claim
65 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity characterization curves of color channels of the color device; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves and normalizing to a characterization curve having a most negative maximum response when compared to a corresponding aim curve.
Claim 22
Independent Claim
54 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity characterization curves of color channels of the color device, said intensity means comprising an achromatic light sensor; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves.
Claim 23
Independent Claim
54 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity characterization curves of color channels of the color device, said intensity means comprising an achromatic light sensor; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves.
Claim 24
Independent Claim
47 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity transfer characterization curves of color channels of the color device; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves.
Claim 25
Independent Claim
47 words
An apparatus for color device calibration, comprising: intensity measurement means for separately measuring intensity transfer characterization curves of color channels of the color device; and calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves.
Claim 26
Dependent Claim
29 words
An apparatus as recited in claim 16, wherein said calibration means creates said calibration curves by transforming the characterization curves using linear aim curves having a balanced white point.
Claim 27
Dependent Claim
19 words
An apparatus as recited in claim 16, wherein said calibration means scales the calibration curves to a saturation value.
Claim 28
Dependent Claim
19 words
An apparatus as recited in claim 16, wherein said color device comprises a monitor, a printer and a scanner.
Claim 29
Dependent Claim
14 words
An apparatus as recited in claim 16, wherein said calibration means comprises a computer.
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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) | 1997-11-07 | 1998-05-09 | 1998-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-07 | 2002-05-09 | 2002-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-07 | 2006-05-09 | 2006-11-08 | $7700.00 | Window Closed / Lapsed |