EP0441609A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Color correction for photographic reproduction
Assignee: Individual
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Filing: 1991-02-06
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Granted: —
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Expires: 2011-02-06
Abstract
Abstract Tone values of a photographic image are stored in a frame store (20) and retrieved from the frame store to produce a corresponding video display. A mouse (17) or trackball is used to locate a point on display and a gamma correction curve look up table (22R,22G,22B) is used to interactively show the effect of color correction. Adjustment can be made via lighter and darker switches (14,15) on the mouse or trackball. These switches subtract or add a bump function to the gamma correction curve in the selected color density plane. The bump function is displaced by the measured tone value in order to achieve more flexible control over the color correction.
Inventors
- 👤 Raphael L. Levien
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 03:39
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407; H04N1/4072; H04N1/46; H04N1/56; H04N1/60; H04N1/6011; H04N1/6027
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
124 words
A method of displaying of an indicator of gamma adjusted tone values of a photographic original comprising the steps of: a)storing a representation of said original in a storage means (20); b)displaying at least a portion of said original on a display means (10); c)isolating an area (1) of the displayed portion and measuring a tone value of the isolated area (213, 215, 903) in a selected one of a plurality of color density planes; d)applying a stored gamma correction curve to the measured tone value (22R, 22G, 22B, 1107, 1109, 1111, 1113) to arrive at a gamma adjusted measured tone value of the isolated area in the selected color density plane; e)displaying an indicator (11, 905) of the gamma adjusted measured tone value.
Claim 2
Dependent Claim
28 words
The method recited in Claim 1 wherein the step of isolating an area comprises locating crosshairs (1) of a cursor over a selected point on a display (10).
Claim 3
Dependent Claim
35 words
The method recited in Claim 1 or 2 wherein the step of displaying the indicator (11) further comprises displaying a numerical value (2) of the gamma adjusted measured tone value on the display means (10).
Claim 4
Dependent Claim
56 words
The method recited in Claim 1, 2 or 3 further comprising displaying a color indication of a first tone (4), the first tone being one increment of less color density than the measured tone and an indication of a second tone (5), the second tone being one increment of more color density than the measured tone.
Claim 5
Independent Claim
184 words
A method of reproducing a photographic original comprising the steps of: a)storing a representation of the original as a plurality of points in a storage means (20), each point representing a measured tone value in a color density plane; b)retrieving at least some of the points from the storage means (20) for displaying (10) at least a portion of the original; c)applying a stored gamma correction curve for at least one of a plurality of color density planes (22R, 22G, 22B, 1107, 1109, 1111, 1113) to each retrieved point to arrive at gamma adjusted measured tone values for each point and displaying the points as a gamma corrected image; d)isolating an area of the gamma corrected image (1) and retrieving from the storage means the measured tone value (213, 215, 903) of the isloated area in a selected color density plane; e)adjusting (32, 33, 1413) the gamma correction curve of the selected color density plane to obtain one of a greater (35, 38, 39, 1411) and lesser (35, 38, 39, 1409) color density in the selected color density plane at the measured tone value.
Claim 6
Dependent Claim
98 words
The method recited in Claim 5 further comprising: f)displaying a color indication of a first tone (4), the first tone being one increment less in density in the selected color density plane than the measured tone value and an indication of a second tone (5), the second tone being one increment greater in density in the selected color density plane than the measured tone value; g)adjusting the gamma correction curve by selecting (14, 15, 913) one of the first and second tones to obtain a desired density in the selected color density plane at the measured tone value.
Claim 7
Dependent Claim
29 words
The method recited in Claim 6 further comprising the step of selecting another color density plane (16, 27, 21) at said isolated area and repeating steps f and g.
Claim 8
Dependent Claim
46 words
The method recited in Claim 5, 6 or 7 further comprising the step of adjusting the gamma correction curve by adding a bump functon (35) to the densities corresponding to the measured tone values, the bump function adjusting the color density for each measured tone value.
Claim 9
Dependent Claim
31 words
The method recited in Claim 8 further comprising the step of displacing (215, 34) the bump function so that the center of the bump function coincides with the measured tone value.
Claim 10
Dependent Claim
40 words
The method recited in Claim 8 comprising selecting adjustment (14, 15, 39, 1401, 1407, 1409, 1411) of the gamma correction curve with the bump function to adjust the gamma correction curve in one of a positive and a negative direction.
Claim 11
Dependent Claim
27 words
The method recited in Claim 8 further comprising the step of storing the gamma correction curve adjusted by the bump function in a storage means (31, 32).
Claim 12
Independent Claim
128 words
An apparatus for displaying of an indicator of gamma adjusted tone values of a photographic original comprising the steps of: a)storage means (20) for storing a representation of said original; b)means for displaying (10) at least a portion of said original; c)means for isolating an area (1) of the displayed portion and for measuring a tone value of the isolated area (213, 215, 903) in a selected one of a plurality of color density planes; d)means for applying a stored gamma correction curve to the measured tone value (22R, 22G, 22B, 1107, 1109, 1111, 1113) to arrive at a gamma adjusted measured tone value of the isolated area in the selected color density plane; e)means for displaying (11, 905) an indicator of the gamma adjusted measured tone value.
Claim 13
Dependent Claim
35 words
The apparatus recited in Claim 12 comprising means for generating crosshairs (1) of a cursor and for locating (17) the crosshairs over a selected point on a display, the selected point being the isolated area.
Claim 14
Dependent Claim
29 words
The apparatus recited in Claim 12 or 13 further comprising means for displaying a numerical value (2) of the gamma adjusted measured tone value on the display means (10).
Claim 15
Dependent Claim
58 words
The apparatus recited in Claim 12, 13 or 14 further comprising means for displaying a color indication of a first tone (4), the first tone being one increment of less color density than the measured tone and an indication of a second tone (5), the second tone being one increment of more color density than the measured tone.
Claim 16
Independent Claim
184 words
An apparatus for reproducing a photographic original comprising: a)storage means (20) for storing a representation of the original as a plurality of points, each point representing a measured tone value; b)means for retrieving at least some of the points from the storage means (20) and for displaying (10) at least a portion of the original; c)means for applying a stored gamma correction curve for at least one of a plurality of color density planes (22R, 22G, 22B, 1107, 1109, 1111, 1113) to each retrieved point to arrive at gamma adjusted measured tone values for each point and for displaying (10) the points as a gamma corrected image; d)means for isolating an area of the gamma corrected corrected image (1) and for retrieving the measured tone value (213, 215, 903) of the isloated area in a selected color density plane; e)means for adjusting (32, 33, 1413) the gamma correction curve of the selected color density plane to obtain one of a greater (35, 38, 39, 1411) and lesser (35, 38, 39, 1409) color density in the selected color density plane at the measured tone value.
Claim 17
Dependent Claim
100 words
The apparatus recited in Claim 16 further comprising: f)means for displaying a color indication of a first tone (4), the first tone being one increment less in density in the selected color density plane than the measured tone and an indication of a second tone (5), the second tone being one increment greater in density in the selected color density plane than the measured tone; and g)means for adjusting the gamma correction curve by selecting (4, 5, 913) one of the first and second tones to obtain a desired density in the selected color density plane at the isolated area.
Claim 18
Dependent Claim
31 words
The apparatus recited in Claim 16 or 17 further comprising means for selecting another color density plane (16, 27, 21) at said isolated area and for repeating steps f and g.
Claim 19
Dependent Claim
46 words
The apparatus recited in Claim 16 or 17 further comprising means for adjusting the gamma correction curves by adding a bump function (35) to the color densities corresponding to the measured tone values, the bump function adjusting the gamma correction curves for each measured tone value.
Claim 20
Dependent Claim
30 words
The apparatus recited in Claim 19 further comprising means for displacing (215, 34) the bump function so that a center of the bump function coincides with the measured tone value.
Claim 21
Dependent Claim
40 words
The apparatus recited in Claim 19 comprising means for selecting adjustment (14, 15, 38, 39, 1401, 1407, 1409, 1411) of the gamma correction curve with the bump function to provide positive adjustment and negative adjustment of the gamma correction curve.
Claim 22
Dependent Claim
23 words
The apparatus recited in Claim 19 further comprising storage means (31, 32) for storing the gamma correction curve adjusted by the bump function.
References Cited (Backward Citations)
No citation records indexed.
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