FAST CALIBRATION OF DISPLAYS USING SPECTRAL-BASED COLORIMETRICALLY CALIBRATED MULTICOLOR CAMERA

• US 20130050504A1
• Filed: 08/28/2012
• Published: 02/28/2013
• Est. Priority Date: 08/29/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Safaee-Rad, Reza, Aleksic, Milivoje
• Granted Patent: US 8,704,895 B2
• Time in Patent Office: Days
• US Class Current: 348/181
• CPC Class Codes: G01J 3/506 measuring the colour produced by screens, monitors, displays or CRTs
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• 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

Abstract

Described are a system and method to calibrate displays using a spectral-based colorimetrically calibrated multicolor camera. Particularly, discussed are systems and methods for displaying a multicolor calibration pattern image on a display unit, capturing the multicolor calibration pattern image with a multicolor camera having a plurality of image sensors, with each image sensor configured to capture a predetermined color of light, comparing a set of reference absolute XYZ coordinates of a set of colors from the multicolor calibration pattern with a set of measured XYZ color coordinates captured using the colorimetrically calibrated camera, and calibrating the display unit based on the comparison between the reference coordinates and the measured coordinates.

Claims

1. An electronic method for calibrating a display unit, the method comprising:

displaying a multicolor calibration pattern image on a display unit;

capturing the multicolor calibration pattern image displayed on the display unit with a multicolor colorimetrically calibrated camera having a plurality of image sensors, with each image sensor configured to capture a predetermined color of light;

comparing a set of reference absolute XYZ coordinates of a set of colors from the multicolor calibration pattern with a set of measured XYZ color coordinates captured using the colorimetrically calibrated camera; and

calibrating the display unit based on the comparison between the reference coordinates and the measured coordinates.

2. The method of claim 1, further comprising the step of determining whether the comparison between the reference absolute XYZ coordinates of a set of colors and the measured XYZ color coordinates is within acceptable color error.

3. The method of claim 2, wherein acceptable color error is less than 1 CIE DE2000 unit.

4. The method of claim 1, further comprising the step of performing a spectral-based calibration of the multicolor camera.

5. The method of claim 1, wherein the multicolor calibration pattern image comprises a plurality of single color images.

6. The method of claim 1, wherein the method may be performed in less than 5 seconds.

7. The method of claim 1, wherein the colorimetrically calibrated camera comprises separate image sensors configured to capture red, green and blue light.

8. The method of claim 1, wherein displaying a multicolor calibration pattern image on a display unit comprises instructing a graphics processor in the display unit to display preselected pixel colors.

9. A system for calibrating a display unit, comprising:

a multicolor camera configured to capture red, green, and blue colors on separate image sensors, with each image sensor configured to capture a predetermined color of light;

a panel driver configured to generate color pattern images on a display unit being calibrated; and

a calibration module configured to set calibration values to adjust the colors being shown on the display.

10. The system of claim 9, further comprising a comparison module configured to compare a set of reference absolute XYZ coordinates of a set of test colors with a corresponding set of measured XYZ color coordinates captured using a colorimetrically calibrated camera and determine whether an acceptable color error is achieved.

11. The system of claim 10, wherein the acceptable color error is less than 1 DE2000 CIE unit.

12. The system of claim 10, further comprising an image capture module configured to spectrally calibrate a multicolor camera prior to capturing color pattern images on a display unit.

13. The system of claim 10, wherein the multicolor camera comprises a 3CCD camera.

14. The system of claim 10, wherein the panel driver is configured to communicate with a graphics processor in the display unit being calibrated.

15. The system of claim 10, wherein the calibration module is configured to store a matrix of calibration coefficients in the display unit.

16. A non-transitory computer-readable medium containing processor executable instructions that when executed perform a method comprising:

displaying a multicolor calibration pattern image on a display unit;

capturing the multicolor calibration pattern image displayed on the display unit with a multicolor camera having a plurality of image sensors, with each image sensor configured to capture a predetermined color of light;

comparing reference absolute XYZ coordinates of a set of colors with a set of measured XYZ color coordinates captured using the colorimetrically calibrated camera; and

calibrating the display unit based on the comparison between the reference coordinates and the measured coordinates.

17. The computer readable medium of claim 16, further containing processor executable instructions that when executed perform a method of determining whether the reference absolute XYZ coordinates of a set of colors with the measured XYZ color coordinates captured using a colorimetrically calibrated camera is within acceptable color error.

18. The computer readable medium of claim 16, further containing processor executable instructions that when executed perform a method of performing a spectral-based calibration of the multicolor camera.

19. The computer readable medium of claim 16, wherein the computer readable medium comprises instructions for calibrating the display unit by storing a matrix of calibration coefficients in the display unit.

20. A system for calibrating a display unit, comprising:

means for displaying a multicolor calibration pattern image on a display unit;

means for capturing the multicolor calibration pattern image displayed on the display unit with a multicolor camera having a plurality of image sensors, with each image sensor configured to capture a predetermined color of light;

means for comparing reference absolute XYZ coordinates of a set of colors with a set of measured XYZ color coordinates captured using the colorimetrically calibrated camera; and

means for calibrating the display unit based on the comparison between the reference coordinates and the measured coordinates.