US4236174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color correction of image display
Assignee: RUDOLF HELL DR-ING GmbH
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Filing: 1979-03-08
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Granted: 1980-11-25
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Expires: 1999-03-08
Abstract
Abstract A method for the correction of the colors of an image, the image being split up into a plurality of image points, wherein a color to undergo maximum correction and a spatially limited domain around the extremity of the vector associated with it in the color space are selected, for each of the image points whose color is to be corrected a test is made to determine whether a color vector associated with the point has its extremity in the domain and correction by addition of a color correction vector is carried out for the color vectors whose extremity is located within the domain, the color correction vector resulting from a freely selectable vector and a superimposed quantity which makes the color correction vector maximum if the color vector to be corrected coincides with the vector of the color which is to undergo maximum correction and which makes it to be the closer to zero the closer the extremity of the color vector to be corrected is to the edge of the domain. Further a hardware corrector circuit for performing said method is disclosed.
Inventors
- 👤 Ferenc Gall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:38
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/62; H04N1/622
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
173 words
A method for the correction of the colors of an image, the image being split up into a plurality of image points, wherein a color to undergo maximum correction and a spatially limited domain around the extremity of the vector associated with it in the color space are selected, for each of the image points whose color is to be corrected a test is made to determine whether a color vector associated with the point has its extremity in the domain and correction by addition of a color correction vector is carried out for the color vectors whose extremity is located within the domain, the color correction vector resulting from a freely selectable vector and a superimposed quantity which makes the color correction vector maximum if the color vector to be corrected coincides with the vector of the color which is to undergo maximum correction and which makes it to be the closer to zero the closer the extremity of the color vector to be corrected is to the edge of the domain.
Claim 2
Independent Claim
173 words
A method for the correction of the colors of an image, the image being split up into a plurality of image points, wherein a color to undergo maximum correction and a spatially limited domain around the extremity of the vector associated with it in the color space are selected, for each of the image points whose color is to be corrected a test is made to determine whether a color vector associated with the point has its extremity in the domain and correction by addition of a color correction vector is carried out for the color vectors whose extremity is located within the domain, the color correction vector resulting from a freely selectable vector and a superimposed quantity which makes the color correction vector maximum if the color vector to be corrected coincides with the vector of the color which is to undergo maximum correction and which makes it to be the closer to zero the closer the extremity of the color vector to be corrected is to the edge of the domain.
Claim 3
Dependent Claim
70 words
A method according to claim 1, wherein the superimposed quantity is determined as a function of the minimum of the ratios of the distances of the extremity of the vector of the color to be corrected from the points of the domain periphery to the distances of the extremity of the vector of the color to undergo maximum correction from, in each case, the identical points of the domain periphery.
Claim 4
Dependent Claim
12 words
A method according to claim 1, wherein the domain is a sphere.
Claim 5
Dependent Claim
20 words
A method according to claim 1, wherein the domain is a cube with sides parallel to the color space axes.
Claim 6
Dependent Claim
61 words
A method according to claim 4, wherein said superimposed quantity is determined as the minimum of the ratios of the distances of the extremity of the vector of the color to be corrected from the cube surfaces to the distances of the extremity of the vector of the color to undergo maximum correction from, in each case, the identical cube surfaces.
Claim 7
Dependent Claim
42 words
A method according to claim 1, wherein the color image is reproduced on a viewing screen and the region and/or color to undergo maximum correction are adjusted with respect to position and size in accordance with the visual observations on the screen.
Claim 8
Dependent Claim
24 words
A method according to claim 6, wherein the original colors are replaced by the corrected colors in the image reproduced on said viewing screen.
Claim 9
Dependent Claim
25 words
A method according to claim 1, wherein parts of the image are excluded from correction, independently of the colors of the image points contained therein.
Claim 10
Dependent Claim
215 words
A logic circuit for performing the method according to claim 1, wherein a first comparator circuit fed with the domain-defining coordinates and the coordinates of the color vector of an image point, a first subtracting circuit fed with the domain-defining coordinates and the coordinates of the vector of the color to undergo maximum correction, a second subtracting circuit fed with the domain-defining coordinates and the coordinates of the color vector of the investigated image point, a dividing circuit for determining the quotient of its input quantities fed with the output quantities of the first and second subtracting circuits, a second comparator circuit for determining the minimum of the quotient fed with the output quantities of the dividing circuits, a circuit for the delivery of the superimposed quantity as a function of the output quantity of the second comparator circuit and fed with the output quantity of said comparator circuit, a multiplying circuit fed with the output quantity of the circuit for delivering the superimposed quantity and the coordinates of a freely selectable vector and an adding circuit fed with the coordinates of the color vector to be corrected and the output quantity of the multiplying circuit and which has an inhibition input subject to the action of the output quantity of the first comparator circuit.
References Cited (Backward Citations)
US4127871A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |