US6888964B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the reproduction of an original scene from an electronically scanned color negative or diapositive film
Assignee: Heidelberger Druckmaschinen AG
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Filing: 2002-03-11
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Granted: 2005-05-03
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Expires: 2022-03-11
Abstract
Abstract A method for the automatic reproduction of the colors of an original scene from an original image present as a color negative or diapositive film includes scanning the original image electronically, and storing the RGB color values of the image points as scanned transmissions or scanned densities. In the RGB color space, a gray straight line is determined, which approximates the cloud of points formed by the scanned densities of the image points in an optimum way. The transmissions are corrected by minimum transmission values in each case being subtracted from the scanned transmissions. Then, reconstructed film exposures are determined, whereby, by the gray straight line, film exposure straight lines are constructed that describe the relationship between the logarithmic film exposures and the corrected densities. Following the normalization of the film exposures to a standard image range, the film exposures are transformed into the LAB color space.
Inventors
- 👤 Mathias Schlüter
- 👤 Holger Klingspohr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:26
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6027
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
166 words
A method for automatic reproduction of colors of an original scene from an original image, which comprises: presenting the original image as one of an electronically scanned color negative and an electronically scanned diapositive film having image points; storing RGB color values of image points as one of the group consisting of scanned transmissions and scanned densities; determining, in an RGB color space, a gray straight line optimally approximating a principal axis of a cloud of points formed by scanned densities of the image points; determining corrected transmissions to which corrected densities correspond by respectively subtracting minimum transmission values from the scanned transmissions; determining reconstructed film exposures utilizing the corrected transmissions, whereby, film exposure straight lines are constructed with the gray straight line, the film exposure straight lines describing a relationship between logarithmic film exposures and the corrected densities; and projecting the reconstructed film exposures onto an image range between a normalized highlight fixed point and a normalized shadow fixed point, and determining normalized film exposures.
Claim 2
Independent Claim
166 words
A method for automatic reproduction of colors of an original scene from an original image, which comprises: presenting the original image as one of an electronically scanned color negative and an electronically scanned diapositive film having image points; storing RGB color values of image points as one of the group consisting of scanned transmissions and scanned densities; determining, in an RGB color space, a gray straight line optimally approximating a principal axis of a cloud of points formed by scanned densities of the image points; determining corrected transmissions to which corrected densities correspond by respectively subtracting minimum transmission values from the scanned transmissions; determining reconstructed film exposures utilizing the corrected transmissions, whereby, film exposure straight lines are constructed with the gray straight line, the film exposure straight lines describing a relationship between logarithmic film exposures and the corrected densities; and projecting the reconstructed film exposures onto an image range between a normalized highlight fixed point and a normalized shadow fixed point, and determining normalized film exposures.
Claim 3
Dependent Claim
47 words
The method according to claim 1 , which further comprises determining a direction of the gray straight line by an eigenvector with a largest eigenvalue of a covariance matrix of image point vectors, components of each image point vector being the scanned densities of the image point.
Claim 4
Dependent Claim
23 words
The method according to claim 2 , wherein the gray straight line runs through a center of gravity of the cloud of points.
Claim 5
Dependent Claim
19 words
The method according to claim 2 , wherein the gray straight line runs through a predefined neutral shadow point.
Claim 6
Dependent Claim
23 words
The method according to claim 1 , wherein the gray straight line runs through a center of gravity of the cloud of points.
Claim 7
Dependent Claim
19 words
The method according to claim 1 , wherein the gray straight line runs through a predefined neutral shadow point.
Claim 8
Dependent Claim
35 words
The method according to claim 1 , which further comprises determining the minimum transmission values from a condition where the corrected densities of an image point of maximum density lie on the gray straight line.
Claim 9
Dependent Claim
20 words
The method according to claim 1 , which further comprises transforming the normalized film exposures into a LAB color space.
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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) | 2008-05-02 | 2008-11-01 | 2009-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-05-02 | 2012-11-01 | 2013-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-05-02 | 2016-11-01 | 2017-05-03 | $7700.00 | Window Closed / Lapsed |