US5933252A
Expired / Lapsed
US
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Color image processing method and apparatus therefor
Assignee: Canon Inc
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Filing: 1995-01-09
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Granted: 1999-08-03
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Expires: 2015-01-09
Abstract
Abstract An image processing method and apparatus for converting image data for use in a color CRT and an image processing device each having a different color reproducible range, for example, a color printer. Color component data of color image data corresponding to a most parts of a color reproducible range of the color printer having a color reproducible region which is narrower than that of the color CTR is not converted. The hue and the brightness of color component data of color image data exceeding the color reproducible range of the color printer are not substantially converted but only chromaticness is converted. A part deviated from the color reproducible range can be approximated to the outer periphery of the reproducible range. Furthermore, the most part of the color reproducible range is correctly color-reproduced and the color image is converted so as to make a portion of the same to be a compressed space of an all color space. Therefore, a color image can be converted such that a color image can be reproduced while maintaining color continuity even if the color deviates from the color reproducible range of the color printer.
Inventors
- 👤 Yasufumi Emori
- 👤 Kazuhiko Onuma
- 👤 Tadataka Koga
- 👤 Yoshizumi Yasuda
- 👤 Yoshinobu Mita
- 👤 Osamu Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:34
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6058
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
100 words
A color image processing apparatus for transmitting color image data to an image forming apparatus, comprising: hue correction table for storing coordinate information of color components on a non-linear hue line expressing the same hue components in a uniform color space; color gamut mapping means for mapping color image data which lie outside of a color reproducible range of the image forming apparatus, along the non-linear hue line by using the coordinate information of said hue correction table; and first output means for outputting the color image data mapped by said color gamut mapping means to the image forming apparatus.
Claim 2
Dependent Claim
100 words
A color image processing apparatus for transmitting color image data to an image forming apparatus, comprising: hue correction table for storing coordinate information of color components on a non-linear hue line expressing the same hue components in a uniform color space; color gamut mapping means for mapping color image data which lie outside of a color reproducible range of the image forming apparatus, along the non-linear hue line by using the coordinate information of said hue correction table; and first output means for outputting the color image data mapped by said color gamut mapping means to the image forming apparatus.
Claim 3
Dependent Claim
18 words
A color image processing apparatus according to claim 1, wherein said uniform color space is expressed by L*a*b*.
Claim 4
Dependent Claim
37 words
A color image processing apparatus according to claim 1, wherein said color gamut mapping means maps the color image data which lie outside of the color gamut of the image forming apparatus into the color reproducible range.
Claim 5
Dependent Claim
103 words
A color image processing method for transmitting color image data to an image forming apparatus, comprising the steps of: mapping color image data which lie outside of a color reproducible range of the image forming apparatus, on a non-linear hue line expressed and constructed by the same hue component as the color image data in a uniform color space by using a table, wherein the table stores coordinate information of color components on the non-linear hue line expressing the same hue components in the uniform color space; and outputting the color image data mapped in said mapping step to the image forming apparatus.
Claim 6
Dependent Claim
103 words
A color image processing method for transmitting color image data to an image forming apparatus, comprising the steps of: mapping color image data which lie outside of a color reproducible range of the image forming apparatus, on a non-linear hue line expressed and constructed by the same hue component as the color image data in a uniform color space by using a table, wherein the table stores coordinate information of color components on the non-linear hue line expressing the same hue components in the uniform color space; and outputting the color image data mapped in said mapping step to the image forming apparatus.
Claim 7
Dependent Claim
77 words
A color image processing method, comprising the steps of: inputting color image data; and performing color gamut mapping on the color image data; wherein in said color gamut mapping step, hue and saturation of the color image data are converted with respect to a hue of the color image data based on a predefined non-linear locus corresponding to the hue, so that the color image data is mapped into a color gamut of an image output device.
Claim 8
Dependent Claim
77 words
A color image processing method, comprising the steps of: inputting color image data; and performing color gamut mapping on the color image data; wherein in said color gamut mapping step, hue and saturation of the color image data are converted with respect to a hue of the color image data based on a predefined non-linear locus corresponding to the hue, so that the color image data is mapped into a color gamut of an image output device.
Claim 9
Dependent Claim
22 words
A color image processing method according to claim 5, wherein the predefined non-linear locus represents the same hue in uniform color space.
Claim 10
Dependent Claim
38 words
A color image processing method according to claim 5, wherein in said color gamut mapping step, the color image data outside the color gamut of the image output device is mapped on a boundary of the color gamut.
Claim 11
Dependent Claim
30 words
A color image processing method according to claim 5, further comprising the step of: outputting an image based on the color image data mapped in said color gamut mapping step.
Claim 12
Dependent Claim
83 words
A color image processing method, comprising the step of: inputting color image data expressed by a plurality of components corresponding to a plurality of coordinates respectively; selecting one of the plurality of coordinates in accordance with a manual operation; and mapping the color image data in a color gamut of an image output apparatus, in a condition in which a component of the color image data corresponding to the selected coordinate is fixed and other components of the color image data are converted.
Claim 13
Dependent Claim
83 words
A color image processing method, comprising the step of: inputting color image data expressed by a plurality of components corresponding to a plurality of coordinates respectively; selecting one of the plurality of coordinates in accordance with a manual operation; and mapping the color image data in a color gamut of an image output apparatus, in a condition in which a component of the color image data corresponding to the selected coordinate is fixed and other components of the color image data are converted.
Claim 14
Dependent Claim
37 words
A color image processing method according to claim 9, wherein said image data is expressed in a color uniform space and each of the plurality of components of color coordinates corresponds to brightness, hue and chromaticness, respectively.
Claim 15
Dependent Claim
91 words
A color image processing apparatus comprising: input means for inputting color image data expressed by a plurality of components corresponding to a plurality of coordinates respectively; selecting means for selecting one of said plurality of coordinates in accordance with a manual operation; and color gamut mapping means for mapping the color image data in a color gamut of an image outputting apparatus, in a condition in which a component of the color image data corresponding to the selected coordinate is fixed and other components of the color image data are converted.
Claim 16
Dependent Claim
91 words
A color image processing apparatus comprising: input means for inputting color image data expressed by a plurality of components corresponding to a plurality of coordinates respectively; selecting means for selecting one of said plurality of coordinates in accordance with a manual operation; and color gamut mapping means for mapping the color image data in a color gamut of an image outputting apparatus, in a condition in which a component of the color image data corresponding to the selected coordinate is fixed and other components of the color image data are converted.
Claim 17
Dependent Claim
81 words
A color image processing apparatus, comprising: input means for inputting color image data; and color gamut mapping means for performing color gamut mapping on the color image data input by said input means; wherein said color gamut mapping means modifies hue and saturation of the color image data with respect to a hue of the color image data, based on a predefined non-linear locus, so that the color image data is mapped into a color gamut of an image output device.
Claim 18
Dependent Claim
81 words
A color image processing apparatus, comprising: input means for inputting color image data; and color gamut mapping means for performing color gamut mapping on the color image data input by said input means; wherein said color gamut mapping means modifies hue and saturation of the color image data with respect to a hue of the color image data, based on a predefined non-linear locus, so that the color image data is mapped into a color gamut of an image output device.
Claim 19
Dependent Claim
150 words
A color image processing apparatus for transmitting color image data to an image forming apparatus comprising: color gamut mapping means for mapping color image data which lie outside of a color reproducible range of the image forming apparatus, along a non-linear hue line expressed and constructed by the same hue components of the color image data in a uniform color space; and first output means for outputting the color image data mapped by said color gamut mapping means to the image forming apparatus, wherein said color gamut mapping means converts the color image data which lie outside of the color gamut of the image forming apparatus, along an axis between maximum and minimum saturations of the same hue component of the color image data in the uniform color space, and after mapping the color image data along the axis, reconverts the mapped color image data along said non-linear hue line.
Claim 20
Dependent Claim
150 words
A color image processing apparatus for transmitting color image data to an image forming apparatus comprising: color gamut mapping means for mapping color image data which lie outside of a color reproducible range of the image forming apparatus, along a non-linear hue line expressed and constructed by the same hue components of the color image data in a uniform color space; and first output means for outputting the color image data mapped by said color gamut mapping means to the image forming apparatus, wherein said color gamut mapping means converts the color image data which lie outside of the color gamut of the image forming apparatus, along an axis between maximum and minimum saturations of the same hue component of the color image data in the uniform color space, and after mapping the color image data along the axis, reconverts the mapped color image data along said non-linear hue line.
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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) | 2002-08-02 | 2003-02-01 | 2003-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-02 | 2007-02-01 | 2007-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-02 | 2011-02-01 | 2011-08-03 | $7700.00 | Window Closed / Lapsed |