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US5819018A
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Image data converting method and image processing apparatus
Assignee: Canon Inc
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Filing: 1994-05-26
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Granted: 1998-10-06
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Expires: 2014-05-26
Abstract
Abstract A color image data processing apparatus and method for inputting color image data of a first color space, selecting representative color image data of a second color space which differs from the first color space in accordance with the input color image data, converting the representative color image data into color image data of the first color space, and computing errors between the input color image data and the representative color image data by using the color image data obtained by the conversion.
Inventors
- 👤 Mitsumasa Sugiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 23:03
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/40075; H04N1/46; H04N1/52
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
77 words
A color image data processing method, comprising the steps of: inputting m-state color image data of a first color space; quantizing the m-state color image data of the first color space into n-state (where n<m) color image data of a second color space; computing error between color represented by the m-state color image data and color represented by the n-state color image data; and diffusing the error to peripheral picture elements of the m-state color image data.
Claim 2
Dependent Claim
77 words
A color image data processing method, comprising the steps of: inputting m-state color image data of a first color space; quantizing the m-state color image data of the first color space into n-state (where n<m) color image data of a second color space; computing error between color represented by the m-state color image data and color represented by the n-state color image data; and diffusing the error to peripheral picture elements of the m-state color image data.
Claim 3
Dependent Claim
17 words
The method according to claim 1, wherein said first color space is RGB, XYZ, or L*a*b* space.
Claim 4
Dependent Claim
34 words
The method according to claim 1, wherein said quantizing step selects color image data representing color in which the error is minimum, from among colors which can be represented by n-state color image data.
Claim 5
Dependent Claim
15 words
The method according to claim 1, wherein said the second color space is YMC space.
Claim 6
Dependent Claim
100 words
A color image data processing apparatus, comprising: inputting means for inputting m-state color image data of a first color space; quantization means for quantizing the m-state color image data of the first color space into n-state (where n<m) color image data of a second color space; computing means for computing error between color represented by the m-state color image data and color represented by the n-state color image data; diffusing means for diffusing the error to peripheral picture elements of the m-state color image data; and image forming means for forming color image based on the n-state color image data.
Claim 7
Dependent Claim
100 words
A color image data processing apparatus, comprising: inputting means for inputting m-state color image data of a first color space; quantization means for quantizing the m-state color image data of the first color space into n-state (where n<m) color image data of a second color space; computing means for computing error between color represented by the m-state color image data and color represented by the n-state color image data; diffusing means for diffusing the error to peripheral picture elements of the m-state color image data; and image forming means for forming color image based on the n-state color image data.
Claim 8
Dependent Claim
17 words
The apparatus according to claim 5, wherein said first color space is RGB, XYZ, or L*a*b* space.
Claim 9
Dependent Claim
34 words
The apparatus according to claim 5, wherein said quantization means selects color image data representing color in which the error is minimum, from among colors which can be represented by n-state color image data.
Claim 10
Dependent Claim
15 words
The apparatus according to claim 5, wherein said the second color space is YMC space.
Claim 11
Dependent Claim
38 words
The apparatus according to claim 5, further comprising: a table for storing relations between the m-state color image data and n-state color image data, wherein said quantization means quantizes the m-state color image data by using said table.
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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) | 2001-10-05 | 2002-04-06 | 2002-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-05 | 2006-04-06 | 2006-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-05 | 2010-04-06 | 2010-10-06 | $7700.00 | Window Closed / Lapsed |