System and Method for Color-Compensating a Video Signal Having Reduced Computational Requirements

• US 20090184976A1
• Filed: 01/22/2008
• Published: 07/23/2009
• Est. Priority Date: 01/22/2008
• Status: Abandoned Application

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Chen, Gang, Ryf, Roland
• Application Number:
  US12/017,984
• Publication Number:
  US 20090184976A1
• Time in Patent Office: Days
• US Class Current: 345/604
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H04N 9/67 for matrixing camera processing pipelines for matrixing of colour signals H04N23/85
• CPC Class Codes: H04N 9/69 for modifying the colour signals by gamma correction controlling camera response for colour signals H04N23/83

Abstract

A system for, and method of, color-compensating a video signal. In one embodiment, the system includes: (1) a first transformation circuit configured to receive and transform a gamma-encoded input video signal into a gamma-encoded RGB video signal R′G′B′ and (2) a second transformation circuit coupled to the first transformation circuit and configured to receive and linearly transform the gamma-encoded RGB video signal R′G′B′ into a chrominance-compensated, gamma-encoded rgb video signal r′g′b′.

Claims

1. A system for color-compensating a video signal, comprising:

a first transformation circuit configured to receive and transform a gamma-encoded input video signal into a gamma-encoded RGB video signal R′

G′

B′

; and

a second transformation circuit coupled to said first transformation circuit and configured to receive and linearly transform said gamma-encoded RGB video signal R′

G′

B′

into a chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

.

2. The system as recited in claim 1 wherein said input video signal contains luma and chroma components.

3. The system as recited in claim 1 further comprising a third transformation circuit coupled to said second transformation circuit and configured to receive and transform said chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

into a system-native format.

4. The system as recited in claim 3 wherein said system-native format contains luma and chroma components.

5. The system as recited in claim 1 wherein said first and second transformation circuits are embodied in a selected one of:

at least one hard-wired logic circuit, and a sequence of software instructions executable in a processor.

6. The system as recited in claim 1 wherein said system is a portion of a video display system and is embodied in an integrated circuit and other parts of said video display system.

7. The system as recited in claim 1 wherein said chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

is chrominance-compensated for a liquid crystal display (LCD)-based video projector.

8. A method of color-compensating a video signal, comprising:

transforming a gamma-encoded input video signal into a gamma-encoded RGB video signal R′

G′

B′

; and

linearly transforming said gamma-encoded RGB video signal R′

G′

B′

into a chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

.

9. The method as recited in claim 8 wherein said input video signal contains luma and chroma components.

10. The method as recited in claim 8 further comprising transforming said chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

into a system-native format.

11. The method as recited in claim 10 wherein said system-native format contains luma and chroma components.

12. The method as recited in claim 8 wherein said transforming and said linearly transforming are carried out in a selected one of:

at least one hard-wired logic circuit, and

a sequence of software instructions executable in a processor.

13. The method as recited in claim 8 wherein said method is carried out in a video display system embodied in an integrated circuit.

14. The method as recited in claim 8 wherein said chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

is chrominance-compensated for a liquid crystal display (LCD)-based video projector.

15. A video display system, comprising:

an input configured to receive a gamma-encoded input video signal;

a first transformation circuit configured to receive and transform said gamma-encoded input video signal into a gamma-encoded RGB video signal R′

G′

B′

;

a second transformation circuit coupled to said first transformation circuit and configured to receive and linearly transform said gamma-encoded RGB video signal R′

G′

B′

into a chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

; and

a third transformation circuit coupled to said second transformation circuit and configured to receive and transform said chrominance-compensated, gamma-encoded rgb video signal r′

g′

b′

into a system-native luma-chroma-chroma format.

16. The system as recited in claim 15 wherein said input video signal contains luma and chroma components.

17. The system as recited in claim 15 wherein said first, second and third transformation circuits are embodied in a selected one of:

at least one hard-wired logic circuit, and

a sequence of software instructions executable in a processor.

18. The system as recited in claim 15 wherein said system is embodied in an integrated circuit.

19. The system as recited in claim 15 wherein said system is a liquid crystal display (LCD)-based video projector.