System and method for automatic calibration of a display device

• US 20040196250A1
• Filed: 04/07/2003
• Published: 10/07/2004
• Est. Priority Date: 04/07/2003
• Status: Abandoned Application

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Mehrotra, Rajiv, Maier, Thomas O.
• Application Number:
  US10/408,529
• Publication Number:
  US 20040196250A1
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2360/144 the light being ambient light
• 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 17/02 for colour television signals
• CPC Class Codes: H04N 17/04 for receivers
• CPC Class Codes: H04N 9/73 Colour balance circuits, e.g. white balance circuits or colour temperature control camera processing pipelines for colour balance H04N23/88

Abstract

A method for evaluating colorimetry of viewing conditions affecting a viewer and calibrating a display device used by the viewer relative to an environment surrounding the display device is based on measuring display colorimetry data and the colorimetry of the viewing conditions and generating display and viewing condition colorimetry data, wherein the viewing conditions include the effect of surround light originating from the environment surrounding the display device and impinging upon the viewer rather than the display device. A color conversion function is calculated from the display colorimetry data and the viewing condition colorimetry data, where the color conversion function is capable of transforming an input video signal into a transformed video signal that shows an improved image based on the colorimetry of the display device and the colorimetry of the viewing conditions. The color conversion function performs color conversion of the input video signal, thereby generating the transformed video signal which is displayed on the display device.

Claims

1. A method for evaluating colorimetry of viewing conditions affecting a viewer and calibrating a display device used by the viewer relative to an environment surrounding the display device, said method comprising the steps of:

(a) measuring the colorimetry of predetermined display colors produced by the display device and generating display colorimetry data;

(b) measuring the colorimetry of the viewing conditions and generating viewing condition colorimetry data, wherein the viewing conditions include the effect of surround light originating from the environment surrounding the display device and impinging upon the viewer rather than the display device;

(c) calculating a color conversion function from the display colorimetry data and the viewing condition colorimetry data, said color conversion function being capable of transforming an input video signal into a transformed video signal that shows an improved image based on the colorimetry of the display device and the colorimetry of the viewing conditions;

(d) using the color conversion function to perform color conversion of the input video signal, thereby generating a transformed video signal; and

(e) displaying the transformed video signal on the display device.

2. The method as claimed in claim 1 wherein the viewing conditions in step (b) further include the effect of ambient light originating from the environment surrounding the display device that reflects off a faceplate or screen of the display device and impinges upon the viewer.

3. The method as claimed in claim 1 wherein the viewer is a home viewer and the surrounding environment is that of a home entertainment system.

4. The method as claimed in claim 1 wherein step (a) measures the colorimetry of a white point of the display device and the color conversion function calculated in step (c) includes a white point correction.

5. The method as claimed in claim 1 wherein step (a) measures the colorimetry of a luminance characteristic of the display device and the color conversion function calculated in step (c) includes a gamma correction.

6. The method as claimed in claim 1 wherein the predetermined display colors are a set of primary colors and step (a) measures the colorimetry of the primary colors of the display device and the color conversion function calculated in step (c) includes a primary color correction.

7. A method for evaluating colorimetry of viewing conditions affecting a viewer and calibrating a display device used by the viewer relative to an environment surrounding the display device, said method comprising the steps of:

(a) measuring the colorimetry of the viewing conditions and generating viewing condition colorimetry data, wherein the viewing conditions include the effect of surround light originating from the environment surrounding the display device and impinging upon the viewer rather than the display device;

(b) calculating a color conversion function from the viewing condition colorimetry data, said color conversion function being capable of transforming an input video signal into a transformed video signal that shows an improved image based on the colorimetry of the viewing conditions;

(c) using the color conversion function to perform color conversion of the input video signal, thereby generating a transformed video signal; and

(d) displaying the transformed video signal on the display device.

8. The method as claimed in claim 7 wherein the viewing conditions in step (a) further include the effect of ambient light originating from the environment surrounding the display device that reflects off a faceplate or screen of the display device and impinges upon the viewer.

9. A system for evaluating colorimetry of viewing conditions affecting a viewer and calibrating a display used by the viewer relative to an environment surrounding the display, said system comprising:

a display unit having a screen;

a sensing stage for measuring (a) the colorimetry of predetermined display colors produced by the display unit and generating display colorimetry data, and (b) measuring the colorimetry of the viewing conditions and generating viewing condition colorimetry data, wherein the viewing conditions include the effect of surround light originating from the environment surrounding the display unit and impinging upon the viewer rather than the screen of the display unit; and

a calibration stage for (a) calculating a color conversion function from the display colorimetry data and the viewing condition colorimetry data, said color conversion function being capable of transforming an input video signal into a transformed video signal that represents an improved image based on the colorimetry of the display unit and the colorimetry of the viewing conditions, and (b) using the color conversion function to perform color conversion of the input video signal, thereby generating a transformed video signal that is displayed on the display unit.

10. The system as claimed in claim 9 wherein the sensing stage includes a remote unit for at least measuring the colorimetry of the predetermined viewing conditions and generating viewing condition colorimetry data.

11. The system as claimed in claim 9 wherein the calibration stage is incorporated into the display unit.

12. The system as claimed in claim 9 wherein the calibration stage is a unit separate from, and connected to, the display unit.

13. The system as claimed in claim 9 wherein the viewing conditions include the effect of ambient light originating from the environment surrounding the display unit that reflects off the screen of the display unit and impinges upon the viewer.

14. A system as claimed in claim 9 wherein the viewer is a home viewer and the surrounding environment is that of a home entertainment system.

15. A system for evaluating colorimetry of viewing conditions affecting a viewer and calibrating a display used by the viewer relative to an environment surrounding the display, said system comprising:

a display unit having a screen;

a sensing stage for measuring the colorimetry of the viewing conditions and generating viewing condition colorimetry data, wherein the viewing conditions include the effect of surround light originating from the environment surrounding the display unit and impinging upon the viewer rather than the screen of the display unit; and

a calibration stage for (a) calculating a color conversion function from the viewing condition colorimetry data, said color conversion function being capable of transforming an input video signal into a transformed video signal that represents an improved image based on the colorimetry of the viewing conditions, and (b) using the color conversion function to perform color conversion of the input video signal, thereby generating a transformed video signal that is displayed on the display unit.

16. The system as claimed in claim 15 wherein the viewing conditions further include the effect of ambient light originating from the environment surrounding the display unit that reflects off the screen of the display unit and impinges upon the viewer.

17. Calibration apparatus for evaluating colorimetry of viewing conditions affecting a viewer and calibrating an input video signal applied to a display used by the viewer relative to an environment surrounding the display, said apparatus comprising:

a sensing stage for measuring the colorimetry of the viewing conditions and generating viewing condition colorimetry data, wherein the viewing conditions include the effect of surround light originating from the environment surrounding the display and impinging upon the viewer rather than the display; and

a calibration stage for calculating a color conversion function from the viewing condition colorimetry data, said color conversion function being capable of transforming the input video signal into a transformed video signal that represents an improved image based on the colorimetry of the viewing conditions.

18. The apparatus as claimed in claim 17 wherein the viewing conditions further include the effect of ambient light originating from the environment surrounding the display that reflects off the display and impinges upon the viewer.