Device, system and method of data conversion for wide gamut displays

• US 7,436,996 B2
• Filed: 05/23/2002
• Issued: 10/14/2008
• Est. Priority Date: 06/07/2001
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Genoa Color Technologies Limited
• Inventors: Ben-Chorin, Moshe, Ben-David, Oded
• Primary Examiner(s): Ahmed, Samir A
• Assistant Examiner(s): Newman, Michael A
• Application Number:
  US10/479,845
• Publication Number:
  US 20050031199A1
• Time in Patent Office: 2,336 Days
• Field of Search: 345/589, 345/590, 345/600, 345/601, 345/602, 382/167, 382/162, 382/254, 358/518, 358/519, 358/500
• US Class Current: 382/167
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• 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 1/6058 Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut
• CPC Class Codes: H04N 9/67 for matrixing camera processing pipelines for matrixing of colour signals H04N23/85

Abstract

A method and system for converting color image data (data outputting from element 202) from a, for example, three-dimensional color space format to a format usable by an n-primary display (206), wherein n is greater than or equal to 3. The system (converter 204) may define a two-dimensional sub-space having a plurality of two-dimensional positions, each position representing a set of n primary color values and a third, scaleable coordinate value for generating an n-primary display input signal (signal inputting toi display 206). Furthermore, the system may receive a three-dimensional color space input signal including out-of range pixel data not reproducible by a three-primary additive display, and may convert the data to side gamut color image pixel data suitable for driving the wide gamut color display.

Claims

1. A method of converting color image data from a three-dimensional color space format to a format suitable for driving an n-primary display, wherein n is greater than or equal to three, the method comprising:

defining a two-dimensional sub-space having a plurality of two-dimensional positions, each position representing a set of n primary color values and a third, scaleable coordinate value, the set of primary color values and the scaleable coordinate value corresponding to a distinct color combination in said three-dimensional color space;

receiving an input signal representing color image data including a plurality of pixels in said three-dimensional color space;

decomposing the three-dimensional color space data of each said pixel into a two-dimensional sub-space component which determines the position of the color of said pixel in said two-dimensional sub-space, and a third, scaling component;

dividing the scaling component for each said pixel by the scaleable coordinate value corresponding to the position of the respective two-dimensional sub-space component of the pixel to produce a scaled component; and

generating an n-primary display input signal representing n-primary input data for each said pixel by multiplying by said scaled component the set of n primary color values at the position of said two-dimensional sub-space component of said pixel in the two-dimensional sub-space.

2. A method according to claim 1 wherein said two-dimensional sub-space includes a predetermined number of positions spanning a predetermined range of color combinations of said three-dimensional color space.

3. A method according to claim 1 wherein said n-primary display input signal comprises n, respective channels, each channel representing image pixel data corresponding to one of a set of n primary colors reproducible by said n-primary display.

4. A method according to claim 1 wherein said third, scaleable coordinate value of each position in said two-dimensional sub-space is responsive to the level of saturation of the color corresponding to each said position.

5. A method according to claim 1 wherein said third, scaleable coordinate value of each position in said two-dimensional sub-space is responsive to the level of brightness of each said position.

6. A method according to claim 1 comprising storing the set of n primary color values and third, scalable component of all colors represented by said two-dimensional sub-space in at least one look-up-table (LUT) having a plurality of entries, each entry containing the set of n primary color values and the third, scaleable coordinate value of a corresponding position in said two-dimensional sub-space.

7. A method according to claim 6 wherein said n primary color values of each entry of said at least one LUT are computed to comply with the condition that a linear combination of the n primaries based on the computed values yields a maximum saturation level for predetermined hue and brightness levels.

8. A method according to claim 6 wherein said n primary color values of each said entry of said at least one LUT are computed to comply with the condition that a linear combination of the n primaries based on the computed values yields a maximum brightness for predetermined chromaticity coordinates.

9. A method according to claim 6 wherein said n primary color values of each said entry of said at least one LUT are computed to comply with the condition that a linear combination of the n primaries based on the computed values yields an optimal spectral match for predetermined chromaticity coordinates.

10. A method according to claim 6 wherein said at least one LUT comprises at least one two-dimensional LUT.

11. A method according to claim 6 wherein generating an n-primary input signal comprises:

retrieving from said at least one LUT the set of n primary color values and the third, scalable coordinate value at the position of said two-dimensional sub-space component of said pixel in the two-dimensional sub-space.

12. A method according to claim 11 wherein said three-dimensional color space comprises a ROB color space.

13. A method according to claim 11 wherein said three-dimensional color space comprises a YCbCr color space.

14. A device for convening color image data from a three-dimensional color space format to a format usable by an n-primary display, wherein n is greater than or equal to three, the device comprising a converter able to define a two-dimensional sub-space having a plurality of two-dimensional positions, each position representing a set of n primary color values and a third, scalable coordinate value, the set of primary color values and the scaleable coordinate value corresponding to a distinct color combination in said three-dimensional color space,

wherein said converter is able to receive an input signal representing color image data including a plurality of pixels in said three-dimensional color space,

wherein said converter is able to decompose the three-dimensional color space data of each said pixel into a two-dimensional sub-space component, which determines the position of the color of said pixel in said two-dimensional sub-space, and a third, scaling component, and

wherein said convener is able to generate an n-primary display input signal representing n-primary input data for each said pixel dividing the scaling component for each said pixel by the scaleable coordinate value corresponding to the position of the respective two-dimensional sub-space component of the pixel to produce a scaled component and by multiplying by said scaled component the set of n primary color values at the position of said two-dimensional sub-space component of said pixel in the two-dimensional sub-space.

15. A device according to claim 14 wherein said two-dimensional sub-space includes a predetermined number of positions spanning a predetermined range of color combinations of said three-dimensional color space.

16. A device according to claim 14 wherein said n-primary display input signal comprises n, respective channels, each channel representing image pixel data corresponding to one of a set of n primary colors reproducible by said n-primary display.

17. A device according to claim 14 wherein said third, scaleable coordinate value of each position in said two-dimensional sub-space is responsive to the level of saturation of the color corresponding to each said position.

18. A device according to claim 14 wherein said third, scaleable coordinate value of each position in said two-dimensional sub-space is responsive to the level of brightness of each said position.

19. A device according to claim 14 comprising at least one look-up-table (LUT) having a plurality of entries, each entry containing the set of n primary color values and the third, scaleable coordinate value of a corresponding position in said two-dimensional sub-space, said at least one LUT storing the set of n primary color values and third, scalable component of all colors represented by said two-dimensional sub-space.

20. A device according to claim 19 wherein said n primary color values of each entry of said at least one LUT are computed to comply with the condition that a linear combination of the n primaries based on the computed values yields a maximum saturation level for predetermined hue and brightness levels.

21. A device according to claim 19 wherein said n primary color values of each said entry of said at least one LUT are computed to comply with the condition that a linear combination of the n primaries based on the computed values yields a maximum brightness for predetermined chromaticity coordinates.

22. A device according to claim 19 wherein said n primary color values of each said entry of said at least one LUT are computed to comply with the condition that a linear combination of the n primaries based on the computed values yields an optimal spectral match for predetermined chromaticity coordinates.

23. A device according to claim 19 wherein said at least one LUT comprises at least one two-dimensional LUT.

24. A device according to claim 19 wherein said converter is capable of retrieving from said at least one LUT the set of n primary color values and the third, scaleable coordinate value at the position of said two-dimensional sub-space component of said pixel in the two-dimensional sub-space.

27. A device according to claim 14, wherein said three-dimensional color space comprises a RGB color space.

28. A device according to claim 14, wherein said three-dimensional color space comprises a YCbCr color space.

25. A color display system comprising:

a device for converting color image data from a three-dimensional color space format to a format usable by an n-primary display, wherein n is greater than or equal to three, the device comprising a converter able to define a two-dimensional sub-space having a plurality of two-dimensional positions each position representing a set of n primary color values and a third, scaleable coordinate value, the set of primary color values and the sad cable coordinate value corresponding to a distinct color combination in said three-dimensional color space, wherein said converter is able to receive an input signal representing color image data including a plurality of pixels in said three-dimensional color space, wherein said convener is able to decompose the three-dimensional color space data of each said pixel into a two-dimensional sub-space component, which determines the position of the color of said pixel in said two-dimensional sub-space, and a third, scaling component, and wherein said converter is able to generate an n-primary display input signal representing n-primary input data for each said pixel dividing the scaling component for each said pixel by the scaleable coordinate value corresponding to the position of the respective two-dimensional sub-space component of the pixel to produce a scaled component and by multiplying by said scaled component the set of n primary color values at the position of said two-dimensional sub-space component of said pixel in the two-dimensional sub-space; and

a color display arranged to receive said n-primary display input signal and to reproduces a color image based on said n-primary display input signal.

26. A system according to claim 25 wherein said color display comprises an n-primary color display.