US4733295A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Luminance selection apparatus for video signal control system
Assignee: COLORGRAPHICS SYSTEMS Inc A CORP OF WI
•
Filing: 1987-05-15
•
Granted: 1988-03-22
•
Expires: 2007-05-15
Abstract
Abstract A luminance selection apparatus for correcting the hue, saturation and luminance of an input color video signal as a function of the luminance of the signal. The system allows setting and storing luminance threshold levels which are used in conjunction with other color selection circuitry to select a region of interest in a video image being displayed. An operator selects a particular hue of interest with color selection circuitry, and then sets a luminance threshold level which discriminates between the same or similar hues in a video image which differ in luminance. In one embodiment, pre-stored digital correction values are retrieved from memory and converted into analog correction signals which modify the phase, amplitude and DC level of the composite video signal only when the input luminance exceeds the threshold level. In another embodiment, independent color derivative signals are employed in conjunction with the luminance of the input video signal to route signals from operator controls to a channel carrying video signals of the selected hue, so that only a selected hue which does not exceed the luminance threshold level receives color correction.
Inventors
- 👤 Robert L. Hemsky
- 👤 Terry L. Tucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:49
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/11
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
138 words
In a color video signal control system, a luminance responsive color correction system for selecting a region of a video image for receiving corrections to a video parameter, comprising: means responsive to the luminance of an input color video signal exceeding a predetermined threshold magnitude for providing a control signal; and means for varying said predetermined threshold magnitude a plurality of times on a given video line; means for detecting the instantaneous hue of said input color video signal; color correction means responsive to said control signal and said detected instantaneous hue for correcting a video parameter of said input color video signal; whereby a video parameter of said input color video signal may be corrected a plurality of times on a given video line as a function of luminance which may vary during said given video line.
Claim 2
Dependent Claim
138 words
In a color video signal control system, a luminance responsive color correction system for selecting a region of a video image for receiving corrections to a video parameter, comprising: means responsive to the luminance of an input color video signal exceeding a predetermined threshold magnitude for providing a control signal; and means for varying said predetermined threshold magnitude a plurality of times on a given video line; means for detecting the instantaneous hue of said input color video signal; color correction means responsive to said control signal and said detected instantaneous hue for correcting a video parameter of said input color video signal; whereby a video parameter of said input color video signal may be corrected a plurality of times on a given video line as a function of luminance which may vary during said given video line.
Claim 3
Dependent Claim
16 words
The color correction system of claim 1, wherein said predetermined threshold magnitude is a positive threshold.
Claim 4
Dependent Claim
16 words
The color correction system of claim 1, wherein said predetermined threshold magnitude is a negative threshold.
Claim 5
Dependent Claim
18 words
The color correction system of claim 1, wherein said predetermined threshold magnitude is selectively variable by an operator.
Claim 6
Dependent Claim
20 words
The color correction system of claim 1, wherein said video parameter comprises the hue of said input color video signal.
Claim 7
Dependent Claim
20 words
The color correction system of claim 1, wherein said video parameter comprises the saturation of said input color video signal.
Claim 8
Dependent Claim
20 words
The color correction system of claim 1, wherein said video parameter comprises the luminance of said input color video signal.
Claim 9
Dependent Claim
16 words
The system of claim 1, wherein said color correction means comprises a phase responsive color corrector.
Claim 10
Dependent Claim
15 words
The system of claim 1, wherein said color correction means comprises a matrix-type color corrector.
Claim 11
Dependent Claim
28 words
The system of claim 1, wherein said threshold magnitude varying means comprises means for repetitively providing a plurality of luminance threshold signals in succession at the subcarrier frequency.
Claim 12
Dependent Claim
26 words
The system of claim 10, further comprising memory means for storing said plurality of luminance threshold signals in locations associated with a plurality of different hues.
Claim 13
Dependent Claim
16 words
The system of claim 1, further comprising operator control means for controlling said predetermined threshold magnitude.
Claim 14
Dependent Claim
132 words
Apparatus for selecting a region of a video image for receiving corrections to a video parameter as a function of the luminance and of a video characteristic of said region, comprising: luminance threshold means responsive to a video characteristic of an input video signal for selecting a particular one of a plurality of luminance threshold signals; operator control means for selectively varying at least one of said plurality of luminance threshold signals; video signal correction means responsive to said video characteristic for selecting a particular one of a plurality of video signal correction signals; and means responsive to said selected one of said luminance threshold signals and said selected one of said video signal correction signals for correcting a parameter of said input video signal to provide a corrected video output signal.
Claim 15
Dependent Claim
132 words
Apparatus for selecting a region of a video image for receiving corrections to a video parameter as a function of the luminance and of a video characteristic of said region, comprising: luminance threshold means responsive to a video characteristic of an input video signal for selecting a particular one of a plurality of luminance threshold signals; operator control means for selectively varying at least one of said plurality of luminance threshold signals; video signal correction means responsive to said video characteristic for selecting a particular one of a plurality of video signal correction signals; and means responsive to said selected one of said luminance threshold signals and said selected one of said video signal correction signals for correcting a parameter of said input video signal to provide a corrected video output signal.
Claim 16
Dependent Claim
15 words
The apparatus of claim 13, wherein said correcting means comprises a phase responsive color corrector.
Claim 17
Dependent Claim
14 words
The apparatus of claim 13, wherein said correcting means comprises a matrix-type color corrector.
Claim 18
Dependent Claim
17 words
The apparatus of claim 13, wherein said correcting means corrects the hue of said input video signal.
Claim 19
Dependent Claim
17 words
The apparatus of claim 13, wherein said correcting means corrects the saturation of said input video signal.
Claim 20
Dependent Claim
17 words
The apparatus of claim 13, wherein said correcting means corrects the luminance of said input video signal.
Claim 21
Dependent Claim
45 words
The apparatus of claim 13, wherein each one of said luminance threshold signals may be a negative threshold or a positive threshold, and further comprising means for selecting between a positive threshold or a negative threshold for a given one of said luminance threshold signals.
Claim 22
Dependent Claim
37 words
The apparatus of claim 13, wherein said luminance threshold means provides a different one of said plurality of said luminance threshold signals for each of a plurality of different hues occurring in a single horizontal video line.
Claim 23
Dependent Claim
41 words
The apparatus of claim 13, wherein said luminance threshold means comprises means for repetitively providing said plurality of luminance threshold signals in succession at the subcarrier frequency, and wherein said video characteristic comprises the instantaneous hue of said input video signal.
Claim 24
Dependent Claim
33 words
The apparatus of claim 13, wherein said video characteristic is hue, and further comprising memory means for storing said plurality of luminance threshold signals in locations associated with a plurality of different hues.
References Cited (Backward Citations)
US3649748A
Cited
US3647941A
Cited
US3737561A
Cited
US3787611A
Cited
US3875583A
Cited
SU930749A1
Cited
US4525736A
Cited
US4533938A
Cited
JPS60124189A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-22 | 1991-09-21 | 1992-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-22 | 1995-09-21 | 1996-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-22 | 1999-09-21 | 2000-03-22 | $7700.00 | Window Closed / Lapsed |