Color signal processing device for multi-primary color display and method thereof

• US 20030098928A1
• Filed: 09/12/2002
• Published: 05/29/2003
• Est. Priority Date: 11/28/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Moon-Cheol
• Granted Patent: US 7,199,839 B2
• Time in Patent Office: Days
• US Class Current: 348/675
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2340/06 Colour space transformation
• 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
• CPC Class Codes: H04N 9/67 for matrixing camera processing pipelines for matrixing of colour signals H04N23/85
• CPC Class Codes: H04N 9/69 for modifying the colour signals by gamma correction controlling camera response for colour signals H04N23/83

Abstract

A color signal processing apparatus for a multi-primary display with a simple circuit construction and a color signal processing method achieves a display white by more than four display primaries. The color signal processing apparatus has a tristimulus value calculation unit calculating tristimulus values (X, Y, Z) of an input color signal, a display primary control signal calculation unit calculating a control signal of each display primary to represent the color signal with a number of display primaries, and a control unit setting the control signal of each display primary with the control signal calculated by the display primary control signal calculation unit to display the color signal. Accordingly, the color signal processing apparatus for the multi-primary display is not only being capable of achieving the display white by more than the four display primaries but also can display the color signals of the entire color gamut according to the number of display primaries being provided and the settings for the respective color coordinates.

Claims

1. A color signal processing device receiving an input color signal having display primaries in a multi-primary color display, comprising:

a tristimulus value calculation unit calculating tristimulus values (X, Y, Z) of the color signal;

a display primary control signal calculation unit calculating a control signal of each display primary to represent the color signal with a number of display primaries based on the calculated tristimulus values (X, Y, Z) of the color signal; and

a control unit setting a display control signal of each display primary with the calculated control signal calculated by the display primary control signal calculation unit to display the color signal on the multi-primary color display.

2. The color signal processing device of claim 1, further comprising:

a gamma characteristic storage unit storing a gamma characteristic of a standard color signal; and

a linear standard color signal calculation unit extracting the gamma characteristic corresponding to the color signal from the gamma characteristic storage unit, and compensating for a non-linear control component of the color signal with the retrieved gamma characteristic and converting the color signal into a linear standard color signal.

3. The color signal processing device of claim 2, wherein the tristimulus value calculation unit calculates the tristimulus values (X, Y, Z) of the linear standard color signal.

4. The color signal processing device of claim 3, further comprising:

a tristimulus value converting constant storage unit storing a tristimulus value converting constant with respect to the linear standard color signal.

5. The color signal processing device of claim 4, wherein the tristimulus value calculation unit retrieves from the tristimulus value converting constant storage unit the tristimulus value converting constant corresponding to the linear standard color signal and calculates the tristimulus values (X, Y, Z) based on the linear standard color signal and the retrieved tristimulus value converting constant.

6. The color signal processing device of claim 1, wherein the display primary control signal calculation unit comprises:

a display primary linear control signal calculation unit calculating a linear control signal of each display primary; and

a display primary non-linear control signal calculation unit calculating a non-linear control signal of each display primary.

7. The color signal processing device of claim 6, wherein the display primary linear control signal caculation unit calculates the linear control signal of each display primary based on the following formula when receiving the tristimulus values (X, Y, Z) corresponding to respective ones of the display primaries:

8. The color signal processing device of claim 7, wherein the display primary linear control signal calculation unit calculates the matrix (C) based on an inverse matrix of multiplication of the matrixes P and K(i.e., {PK}⁻

1), and the matrix (X Y Z)^T when the number of the display primaries is three (3).

9. The color signal processing device of claim 7, wherein the display primary linear control signal calculation unit calculates the linear control signal of an ith display primary of the display primaries by the following formula when the number of the display primaries is more than three (3):

C_i=a_i·

X+b_i·

Y+c_i·

Z(i=1,2, . . . ,Q),

where a_i, b_i and c_i are respective proportional constants when the ith display primary is represented by the tristimulus values (X, Y, Z).

10. The color signal processing device of claim 9, wherein the tristimulus value calculation unit combines linear control signals of the display primaries (C₁ through C_Q) at an equal interval and calculates the tristimulus values (X, Y, Z) corresponding to a combination of the linear control signals of the respective display primaries, and the display primary linear control signal calculation unit calculates the proportional constants a_i, b_i and c_i, based on the linear control signal (Ci) of one of the display primaries and the tristimulus values (X, Y, Z).

11. The color signal processing device of claim 9, further comprising:

a proportional constant storage unit storing the proportional constants a_i, b_i and c_i.

12. The color signal processing device of claim 11, wherein the display primary linear control signal calculation unit calculates a Q×

3 matrix (C) based on the calculated linear control signal of the ith display primary, the Q×

3 matrix (C) being;

13. The color signal processing device of claim 12, further comprising an electro-optical characteristic storage unit storing an electro-optical characteristic of the multi-primary color display, and the display primary non-linear control signal calculation unit calculates the non-linear control signal corresponding to the linear control signal of the ith display primary which is calculated based on the electro-optical characteristic and a matrix C_N of the non-linear control signal corresponding to the Q×

3 matrix (C).

14. The color signal processing device of claim 13, wherein the control unit sets a display control signal of each display primary according to the calculated matrix (CN) of the non-linear control signal.

15. A method of processing an input color signal in a multi-primary color display of a color signal processing device, comprising:

calculating tristimulus values (X, Y, Z) of the color signal;

calculating a control signal of each display primary to represent the color signal with a number of display primaries in response to the tristimulus values (X, Y, Z); and

setting a display primary control signal of each display primary with the calculated control signal to display the color signal.

16. The method of claim 15, further comprising

extracting a gamma characteristic corresponding to the color signal from a gamma characteristic storage unit that stores the gamma characteristic of a standard color signal;

and

compensating for a non-linear control component of the color signal with the extracted gamma characteristic and then converting the color signal into a linear standard color signal.

17. The method of claim 16, wherein the calculating of the tristimulus values comprises calculating the tristimulus values (X, Y, Z) of the converted linear standard color signal.

18. The method of claim 17, further comprising:

retrieving a tristimulus value converting constant corresponding to the converted linear standard color signal from a tristimulus value converting constant storage unit which stores the tristimulus converting constant corresponding to the linear standard color signal.

19. The method of claim 18, wherein the calculating of the tristimulus values comprises calculating the tristimulus values (X, Y, Z) based on the converted linear standard color signal and the retrieved tristimulus value converting constant.

20. The method of claim 15, wherein the calculating of the control signal comprises:

calculating a linear control signal of each display primary; and

calculating a non-linear control signal of each display primary.

21. The method of claim 20, wherein the calculating of the linear control signal comprises calculating the linear control signal of each display primary when the tristimulus values (X, Y, Z) are driven with the display primaries based on the following formula:

22. The method of claim 21, wherein the calculating of the linear control signal comprises calculating the matrix (C) based on an inverse matrix of multiplication of the matrixes P and K, i.e., ({PK}⁻

1), and the matrix (X Y Z)^T when the number of display primaries is three (3).

23. The method of claim 21, wherein the the calculating of linear control signal comprises calculating the linear control signal of the ith display primary of the display primaries by the following formula when the Q number of the display primaries is more than three (3):

C_i=a_i·

X+b_i·

Y+c_i·

Z(i=1,2, . . . , Q)

where a_i, b_i and c_i are proportional constants when an ith display primary is represented in the tristimulus values (X, Y, Z).

24. The method of claim 23, further comprising:

retrieving the proportional constants from a proportional constant storage unit that stores the proportional constants a_i, b_i and c_i.

25. The method of claim 23, wherein the calculating of the tristimulus value comprises combining linear control signals of display primaries (C₁ through C_Q) at an equal interval and calculating the tristimulus values (X, Y, Z) corresponding to a combination of the linear control signals of the respective display primaries, and the calculating of the linear control signal comprises calculating the proportional constants a_i, b_i and c_i based on the linear control signal (C_i) of one display primary of the certain display primaries and based on the tristimulus values (X, Y, Z).

26. The method of claim 23, wherein the calculating of the linear control signal comprises calculating a Q×

3 matrix (C) based on the calculated linear control signal of ith display primary, the Q×

3 matrix (C) being;

27. The method of claim 26, wherein the calculating of the non-linear control signal comprises calculating the non-linear control signal corresponding to the linear control signal of the ith display primary which is calculated based on an electro-optical characteristic of the multi-primary color display and a matrix C_N of the non-linear control signal corresponding to the Q×

3 matrix (C).

28. The method of claim 27, wherein the setting of the control signal of each display primary comprises setting the calculated matrix (C_N) of the non-linear control signal as the control signal.

29. A color signal processing device for displaying an input color signal having display primaries and a non-linear control component in a multi-primary color display, comprising:

a linear standard color signal calculation unit having a gamma characteristic corresponding to the non-linear control component of the input color signal and calculating a linear standard color signal from the input color signal in response to the gamma characteristic;

a tristimulus value calculation unit having a tristimulus value converting constant corresponding to the linear standard color signal and calculating tristimulus values of the linear standard color signal in response to the converted linear standard color signal and the tristimulus value converting constant;

a display primary control signal calculation unit having a proportional constant and a display electro-optical characteristic corresponding to the linear standard color signal and calculating a display primary control signal of each display primary in response to the proportional constant, the display electro-optical characteristic, and the tristimulus values to represent the linear standard color signal with a number of display primaries; and

a control unit controlling the multi-primary color display with the display primary control signal of each one of the display primaries to display the converted linear standard color signal corresponding to the input color signal on the multi-primary color display.

30. The color signal processing device of claim 29, further comprising:

a gamma characteristic storage unit storing the gamma characteristic of a standard color signal,

a tristimulus value converting constant storage unit storing the tristimulus value converting constant;

a proportional constant storage unit storing the proportional constant; and

a display electro-optical characteristic storing the display electro-optical characteristic.

31. The color signal processing device of claim 29, wherein the display primary control signal calculation unit comprises a display primary linear control signal calculation unit generating a linear control signal of each display primary of the converted linear standard color signal in response to the proportional constant.

32. The color signal processing device of claim 31, wherein the display primary control signal calculation unit comprises a display primary non-linear control signal calculation unit controlling a non-linear control signal of the converted linear standard color signal in response to the electro-optical characteristic and the linear control signal of each display primary.

33. The color signal processing device of claim 31, wherein the input color signal is a non-linear standard color signal different from the linear standard color signal, and the converted linear standard color signal is one of a NTSC-TV system, a PAL-TV system, and an sRGB system.