DISPLAY COLOR CORRECTING SYSTEM

• US 20110148912A1
• Filed: 03/03/2011
• Published: 06/23/2011
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: MARCU, Gabriel G., Chen, Wei
• Granted Patent: US 8,094,167 B2
• Time in Patent Office: Days
• US Class Current: 345/601
• 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 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 1/603 controlled by characteristics of the picture signal generator or the picture reproducer
• CPC Class Codes: H04N 9/68 for controlling the amplitude of colour signals, e.g. automatic chroma control circuits H04N9/71, H04N9/73 take precedence; camera processing pipelines for controlling the colour saturation of colour signals H04N23/86

Abstract

A display color-correcting system is provided. Color response values are measured that go into the vertices of polyhedra in a cubic color output space of the display. A set of corresponding values for the display is built from intermediate values determined between the measured color response values. The intermediate values are determined by decomposition and interpolation of interpolation volumes in the cubic color output space. Each of the interpolation volumes is the combined volume of a selected polyhedron within the cubic color output space and a predetermined volume of space between the selected polyhedron and the next polyhedron within the cubic color output space. The set of corresponding values is converted into decoupled RGB adjustment values that specify the RGB signals independently for the display to produce corrected colors. The RGB adjustment values are saved into one or more look-up tables.

Claims

1. (canceled)

2. A display color correcting method, comprising:

providing a first plurality of input color values to the display, wherein the first plurality of input color values correspond to a plurality of vertices of a plurality of cubes within a cubic color space of the display, each cube having two vertices arranged along a gray diagonal of the cubic color space;

measuring a response value for each of the first plurality of input color values;

determining a first plurality of calibration values corresponding to the first plurality of input color values based on the measured response values; and

determining a second plurality of calibration values for a second plurality of input color values by interpolating the first plurality of calibration values.

3. The method of claim 2, wherein each of the first and second plurality of calibration values comprises a red channel value, a green channel value, and a blue channel value.

4. The method of claim 3, further comprising decoupling the red, green, and blue channel correction values of each of the first and second plurality of calibration values.

5. The method of claim 2, wherein interpolating the first plurality of calibration values further comprises tetrahedral decomposition of adjacent cube pairs of the plurality of cubes to provide a plurality of tetrahedrons.

6. The method of claim 5, wherein determining a second plurality of calibration values further comprises:

apportioning weights to the vertices of each of the plurality of tetrahedrons, wherein the weight of each vertex of each of the plurality of tetrahedrons is between 0 and 1; and

selecting one tetrahedron from the plurality of tetrahedrons, wherein the one tetrahedron has the minimum sum of the absolute weights for a desired one of the second plurality of input color values.

7. The method of claim 6, wherein the calibration value of the desired one of the second plurality of input color values is used to identify red, green, and blue channel correction values.

8. The method of claim 2, wherein each cube of the plurality of cubes has a length, a height, and a width, and wherein at least one of the plurality of cubes has a length, height, or width that is different from a respective length, height, or width of at least one other of the plurality of cubes.

9. A display color correcting method, comprising:

providing a first plurality of input color values to the display, wherein the first plurality of input color values correspond to a plurality of vertices of a plurality of cuboids within a cubic color space of the display, each cuboid having two vertices on a gray tracking correction line along an approximate diagonal of the cubic color space, wherein the gray tracking correction line is derived by measuring a plurality of points in the cubic color space;

measuring a response value for each of the first plurality of input color values;

determining a first plurality of calibration values corresponding to the first plurality of input color values based on the measured response values; and

determining a second plurality of calibration values for a second plurality of input color values by interpolating the first plurality of calibration values.

10. The method of claim 9, wherein the gray tracking correction line comprises at least 16 points in the cubic color space.

11. The method of claim 9, wherein each of the first and second plurality of calibration values comprises a red channel value, a green channel value, and a blue channel value.

12. The method of claim 11, further comprising decoupling the red, green, and blue channel correction values of each of the first and second plurality of gray calibration values.

13. The method of claim 9, wherein interpolating the first plurality of calibration values further comprises tetrahedral decomposition of adjacent cuboid pairs of the plurality of cuboids to provide a plurality of tetrahedrons.

14. The method of claim 13, wherein determining a second plurality of calibration values further comprises:

apportioning weights to the vertices of each of the plurality of tetrahedrons, wherein the weight of each vertex of each of the plurality of tetrahedrons is between 0 and 1; and

selecting one tetrahedron from the plurality of tetrahedrons, wherein the one tetrahedron has the minimum sum of the absolute weights for a desired one of the second plurality of input color values.

15. The method of claim 14, wherein the calibration value of the desired one of the second plurality of input color values is used to identify red, green, and blue channel correction values.

16. The method of claim 9, wherein each cuboid of the plurality of cuboids has a length, a height, and a width, and wherein at least one of the plurality of cuboids has a length, height, or width that is different from a respective length, height, or width of at least one other of the plurality of cuboids.

17. The method of claim 9, wherein each cuboid of the plurality of cuboids has a length, a height, and a width, and wherein at least one of the plurality of cuboids is not a cube having equal length, height, and width dimensions.