System and method of data conversion for wide gamut displays

• US 20050031199A1
• Filed: 12/08/2003
• Published: 02/10/2005
• 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 (Samsung Electronics Co. Ltd.)
• Inventors: Ben-Chorin, Moshe, Ben-David, Oded
• Granted Patent: US 7,436,996 B2
• Time in Patent Office: Days
• US Class Current: 382/162
• 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 to a form usable by a wide gamut color display, the method comprising:

receiving an input signal, in a three-dimensional color space, representing three-dimensional color image pixel data including out-of-range pixel data not reproducible by a three-primary additive display;

converting said three-dimensional color space input data into wide color gamut image pixel data corresponding to at least some of said out-of-range pixel data; and

based on said wide color gamut image pixel data, generating a wide color gamut input signal suitable for driving said wide gamut color display.

2. A method according to claim 1 wherein said wide gamut color display comprises a more-than-three-primary color display and wherein said wide gamut input signal represents more-than-three-primary color image pixel data suitable for driving said more-than-three-primary color display.

3. A method according to claim 2 wherein said wide gamut input signal comprises more than three, respective channels, each channel representing image pixel data corresponding to one primary color in a set of more than three, respective, primary colors reproducible by said more-than-three-primary color display.

4. A method according to claim 3, wherein converting said three-dimensional input signal comprises:

defining a conversion color space having a plurality of positions, each position corresponding to a distinct linear combination of said more than three primary colors, said linear combination representing a distinct color combination in said three-dimensional-color space; and

for each pixel of said three-dimensional color space input pixel data, constructing a corresponding wide gamut pixel based on the linear combination of primaries corresponding to the position of said pixel in said conversion color space.

39. A method according to claim 1, wherein said three-dimensional color space comprises a RGB color space.

40. A method according to claim 1, wherein said three-dimensional color space comprises a YCbCr color space.

5. 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; and

generating an n-primary display input signal representing n-primary input data for each said pixel based on 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, scaled by the third, scaling component of said pixel.

6. A method according to claim 5 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.

7. A method according to claim 5 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.

8. A method according to claim 5 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.

9. A method according to claim 5 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.

10. A method according to claim 5 comprising storing the set of n primary color values and third, scaleable 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.

11. A method according to claim 10 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.

12. A method according to claim 10 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.

13. A method according to claim 10 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.

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

15. A method according to claim 10 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, scaleable coordinate value at the position of said two-dimensional sub-space component of said pixel in the two-dimensional sub-space;

scaling the retrieved third, scaleable coordinate value based on the third, scaling component of the decomposed input data, to produce a scaled third component;

normalizing the retrieved n primary color values based on the scaled third component to produce n normalized primary color values; and

generating said n-primary display input signal based on said n normalized primary color values.

16. A method according to claim 15 wherein said three-dimensional color space comprises a RGB color space.

17. A method according to claim 15 wherein said three-dimensional color space comprises a YCbCr color space.

18. A device for converting color image data into a form usable by a wide gamut color display, the device comprising:

a converter able to receive an input signal, in a three-dimensional color space, representing three-dimensional color image pixel data including out-of-range pixel data not reproducible by a three-primary additive display,

said converter is able to convert said three-dimensional color space input data into wide color gamut image pixel data corresponding to at least some of said out-of-range pixel data, said converter is able to generate, based on said wide color gamut image pixel data, a wide color gamut input signal suitable for driving said wide gamut color display.

19. A device according to claim 18 wherein said wide gamut color display comprises a more-than-three-primary color display and wherein said wide gamut input signal represents more-than-three-primary color image pixel data suitable for driving said more-than-three-primary color display.

20. A device according to claim 19 wherein said wide gamut input signal comprises more than three, respective channels, each channel representing image pixel data corresponding to one primary color in a set of more than three, respective, primary colors reproducible by said more-than-three-primary color display.

21. A device according to claim 20, wherein said converter is able to define a conversion color space having a plurality of positions, each position corresponding to a distinct linear combination of said more than three primary colors, said linear combination representing a distinct color combination in said three-dimensional-color space, and wherein said converter is able to construct, for each pixel of said three-dimensional color space input pixel data, a corresponding wide gamut pixel based on the linear combination of primaries corresponding to the position of said pixel in said conversion color space.

33. A device according to claim 18 wherein said three-dimensional color space comprises a RGB color space.

34. A device according to claim 18 wherein said three-dimensional color space comprises a YCbCr color space.

22. 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 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 converter is able to generate an n-primary display input signal representing n-primary input data for each said pixel based on 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, scaled by the third, scaling component of said pixel.

23. A device according to claim 22 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.

24. A device according to claim 22 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.

25. A device according to claim 22 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.

26. A device according to claim 22 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.

27. A device according to claims 22 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, scaleable component of all colors represented by said two-dimensional sub-space.

28. A device according to claim 27 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.

29. A device according to claim 27 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.

30. A device according to claim 27 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.

31. A device according to claims 27 wherein said at least one LUT comprises at least one two-dimensional LUT.

32. A device according to claim 27 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,

wherein said converter is capable of scaling the retrieved third, scaleable coordinate value based on the third, scaling component of the decomposed input data, to produce a scaled third component,

wherein said converter is capable of normalizing the retrieved n primary color values based on the scaled third component to produce n normalized primary color values, and

wherein said converter is capable of generating said n-primary display input signal based on said n normalized primary color values.

41. A device according to claim 22, wherein said three-dimensional color space comprises a RGB color space.

42. A device according to claim 22, wherein said three-dimensional color space comprises a YCbCr color space.

35. A color display system comprising:

a device for converting color image data into a form usable by a wide gamut color display, the device comprising a converter able to receive an input signal, in a three-dimensional color space, representing three-dimensional color image pixel data including out-of-range pixel data not reproducible by a three-primary additive display, said converter is able to convert said three-dimensional color space input data into wide color gamut image pixel data corresponding to at least some of said out-of-range pixel data, said converter is able to generate, based on said wide color gamut image pixel data, a wide color gamut input signal suitable for driving said wide gamut color display; and

a color display arranged to receive said wide gamut display input signal and to reproduces a color image based on said wide gamut display input signal.

36. A system according to claim 35 wherein said color display comprises a wide color gamut display.

37. 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 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 converter is able to generate an n-primary display input signal representing n-primary input data for each said pixel based on 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, scaled by the third, scaling component of said pixel; 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.

38. A system according to claim 37 wherein said color display comprises an n-primary color display.