US5974173A
Expired / Lapsed
US
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Image data color correction method
Assignee: Sharp Corp
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Filing: 1997-12-09
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Granted: 1999-10-26
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Expires: 2017-12-09
Abstract
Abstract An image data color correction method includes the step of obtaining a first error with respect to input image data by looking up a first look-up table (A), the step of obtaining a second error with respect to the first error by looking up a second look-up table (B), the step of obtaining an error coefficient on the basis of the ratio between the remainder obtained by dividing the gradation level of the input data by a predetermined number of gradation levels and the predetermined number of gradation levels, and the step of adding the first error and the product of the error coefficient and the second error to the input image data, thereby interpolating the first error and correcting the input image data.
Inventors
- 👤 Kenji Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:50
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6016; H04N1/6019
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
190 words
An image data color correction method using look-up tables, comprising: (1) the step of obtaining a first error with respect to input image data by looking up a first look-up table; (2) the step of obtaining a second error with respect to the first error by looking up a second look-up table; (3) the step of obtaining an error coefficient on the basis of a ratio between a remainder obtained by dividing a gradation level of the input data by a predetermined number of gradation levels and the predetermined number of gradation levels; and (4) the step of adding the first error and a product of the error coefficient and the second error to the input image data, wherein said first look-up table defines differences between input image data at representative points, separated at intervals of the predetermined number of gradation levels, and ideal values as first errors, and said second look-up table defines a change in the first error, which occurs when the gradation level of the input image data at each of the representative points is advanced by the predetermined number of gradation levels, as a second error.
Claim 2
Dependent Claim
190 words
An image data color correction method using look-up tables, comprising: (1) the step of obtaining a first error with respect to input image data by looking up a first look-up table; (2) the step of obtaining a second error with respect to the first error by looking up a second look-up table; (3) the step of obtaining an error coefficient on the basis of a ratio between a remainder obtained by dividing a gradation level of the input data by a predetermined number of gradation levels and the predetermined number of gradation levels; and (4) the step of adding the first error and a product of the error coefficient and the second error to the input image data, wherein said first look-up table defines differences between input image data at representative points, separated at intervals of the predetermined number of gradation levels, and ideal values as first errors, and said second look-up table defines a change in the first error, which occurs when the gradation level of the input image data at each of the representative points is advanced by the predetermined number of gradation levels, as a second error.
Claim 3
Dependent Claim
44 words
An image data color correction method according to claim 1, wherein said first and second look-up tables have the same data amount, and the same addresses are assigned to said first and second look-up tables to simultaneously access said first and second look-up tables.
Claim 4
Dependent Claim
43 words
An image data color correction method according to claim 1, wherein said first and second look-up tables have the same data amount, and consecutive addresses are assigned to said first and second look-up tables to consecutively access said first and second look-up tables.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-10-25 | 2003-04-26 | 2003-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-25 | 2007-04-26 | 2007-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-25 | 2011-04-26 | 2011-10-26 | $7700.00 | Window Closed / Lapsed |