US5485284A
Expired / Lapsed
US
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Image processing system for performing color image data calibration
Assignee: Canon Inc
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Filing: 1992-12-30
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Granted: 1996-01-16
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Expires: 2012-12-30
Abstract
Abstract An image reading apparatus measures, color by color, an average transmission-density signal based upon image information obtained from a color original through which light is transmitted, converts the measured average transmission-density signal of every color into a subject-lightness signal of every color, and effects a conversion into a reference color stimulus signal, which is indicated by the apex of a triangle substantially circumscribed by a spectrum locus of a predetermined chromaticity diagram, based upon the converted subject-lightness signal of every color.
Inventors
- 👤 Seita Shono
- 👤 Akihiro Usami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:59
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/603
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
105 words
A color image processing apparatus comprising: obtaining means for obtaining color signal data corresponding to a predetermined color by using an input system, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; and calibration means for calibrating the input system so that the color signal data is substantially equivalent to expected color signal data of the predetermined data.
Claim 2
Dependent Claim
105 words
A color image processing apparatus comprising: obtaining means for obtaining color signal data corresponding to a predetermined color by using an input system, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; and calibration means for calibrating the input system so that the color signal data is substantially equivalent to expected color signal data of the predetermined data.
Claim 3
Dependent Claim
17 words
A color image processing apparatus according to claim 1, wherein said input system has a reading unit.
Claim 4
Dependent Claim
32 words
A color image processing apparatus according to claim 1, wherein said obtaining means obtains the color signal data using a conversion matrix, and said calibrating means calibrates elements of the conversion matrix.
Claim 5
Dependent Claim
102 words
A color image processing method comprising the steps of: obtaining color signal data corresponding to a predetermined color by using an input system, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; and calibrating the input system so that the color signal data is substantially equivalent to expected color signal data of the predetermined color.
Claim 6
Dependent Claim
102 words
A color image processing method comprising the steps of: obtaining color signal data corresponding to a predetermined color by using an input system, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; and calibrating the input system so that the color signal data is substantially equivalent to expected color signal data of the predetermined color.
Claim 7
Dependent Claim
17 words
A color image processing method according to claim 4, wherein said input system is a reading system.
Claim 8
Dependent Claim
32 words
A color image processing method according to claim 4, wherein said obtaining step obtains the color signal data using a conversion matrix, and said calibrating step calibrates elements of the conversion matrix.
Claim 9
Dependent Claim
30 words
A color image processing method according to claim 4, wherein the three stimulus data are R: (0.7347, 0.2653), G: (-0.0860, 1.0860) and B: (0.0957, -0.0314) on the xy chromaticity diagram.
Claim 10
Dependent Claim
113 words
A color image processing apparatus comprising: obtaining means for obtaining color signal data corresponding to a predetermined color, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; output means for outputting a color image in accordance with the color signal data using an output system; and calibration means for calibrating the output system so that the output color image is substantially equivalent to the predetermined color.
Claim 11
Dependent Claim
113 words
A color image processing apparatus comprising: obtaining means for obtaining color signal data corresponding to a predetermined color, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; output means for outputting a color image in accordance with the color signal data using an output system; and calibration means for calibrating the output system so that the output color image is substantially equivalent to the predetermined color.
Claim 12
Dependent Claim
17 words
A color image processing apparatus according to claim 8, wherein said output system has a recording unit.
Claim 13
Dependent Claim
30 words
A color image processing apparatus according to claim 8, wherein said three stimulus data are R: (0.7347, 0.2653), G: (-0.0860, 1.0860) and B: (0.0957, -0.0314) on the xy chromaticity diagram.
Claim 14
Dependent Claim
107 words
A color image processing method comprising the steps of: obtaining color signal data corresponding to a predetermined color, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; outputting a color image in accordance with the color signal data using an output system; and calibrating the output system so that the outputted color image is substantially equivalent to the predetermined color.
Claim 15
Dependent Claim
107 words
A color image processing method comprising the steps of: obtaining color signal data corresponding to a predetermined color, the color signal data being expressed by a combination of three stimulus data corresponding to vertices of a triangle which substantially contacts a spectrum locus of an xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlaps the locus of a purple boundary formed by connecting 380 nm and 780 nm; outputting a color image in accordance with the color signal data using an output system; and calibrating the output system so that the outputted color image is substantially equivalent to the predetermined color.
Claim 16
Dependent Claim
17 words
A color image processing method according to claim 11, wherein the output system is a recording system.
Claim 17
Dependent Claim
137 words
An image processing apparatus comprising: generating means for generating correction data for converting first color image data represented in a first color space, which depends on an image reading unit, to second color image data represented in a second color space, which is formed as a triangle on a xy chromaticity diagram, said triangle substantially contacting a spectrum locus of the xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlapping the locus of a purple boundary formed by connecting 380 nm and 780 nm; input means for inputting first color image data in the first color space from the image reading unit; conversion means for converting the first color image data to second color image data in the second color space based on the correction data generated by said generating means.
Claim 18
Dependent Claim
137 words
An image processing apparatus comprising: generating means for generating correction data for converting first color image data represented in a first color space, which depends on an image reading unit, to second color image data represented in a second color space, which is formed as a triangle on a xy chromaticity diagram, said triangle substantially contacting a spectrum locus of the xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlapping the locus of a purple boundary formed by connecting 380 nm and 780 nm; input means for inputting first color image data in the first color space from the image reading unit; conversion means for converting the first color image data to second color image data in the second color space based on the correction data generated by said generating means.
Claim 19
Dependent Claim
66 words
An image processing apparatus according to claim 13, wherein said generating means generates correction data based on third color image data and fourth color image data, wherein the third color image data is represented in the first color space and obtained by reading an original image using the image reading unit, and the fourth color image data represents the original image in the second color space.
Claim 20
Dependent Claim
15 words
An image processing apparatus according to claim 13 wherein said converting means performs matrix operation.
Claim 21
Dependent Claim
137 words
An image processing method comprising the steps of: generating correction data for converting first color image data represented in a first color space, which depends on an image reading unit, to second color image data represented in a second color space, which is formed as a triangle on a xy chromaticity diagram, said triangle substantially contacting a spectrum locus corresponding to a real color region of the xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlapping the locus of a purple boundary formed by connecting 380 nm and 780 nm; inputting first color image data in the first color space from the image reading unit; converting the first color image data to second color image data in the second color space based on the correction data generated in said generating step.
Claim 22
Dependent Claim
137 words
An image processing method comprising the steps of: generating correction data for converting first color image data represented in a first color space, which depends on an image reading unit, to second color image data represented in a second color space, which is formed as a triangle on a xy chromaticity diagram, said triangle substantially contacting a spectrum locus corresponding to a real color region of the xy chromaticity diagram at wavelengths of about 505 nm and 525 nm, and substantially overlapping the locus of a purple boundary formed by connecting 380 nm and 780 nm; inputting first color image data in the first color space from the image reading unit; converting the first color image data to second color image data in the second color space based on the correction data generated in said generating step.
Claim 23
Dependent Claim
69 words
An image processing method according to claim 16, wherein the correction data is generated, in said generating step, based on third color image data and fourth color image data, wherein the third color image data is represented in the first color space and obtained by reading an original image using the image reading unit, and the fourth color image data represents the original image in the second color space.
Claim 24
Dependent Claim
17 words
An image processing method according to claim 16, wherein matrix operation is performed in said converting step.
References Cited (Backward Citations)
US4751535A
Cited
US4941038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-15 | 1999-07-17 | 2000-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-15 | 2003-07-17 | 2004-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-15 | 2007-07-17 | 2008-01-16 | $7700.00 | Window Closed / Lapsed |