Color reproducing system

• US 6,538,742 B1
• Filed: 02/23/2000
• Issued: 03/25/2003
• Est. Priority Date: 02/25/1999
• Status: Expired due to Fees

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Ohsawa, Kenro
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): LAUCHMAN, LAYLA G
• Application Number:
  US09/510,787
• Time in Patent Office: 1,126 Days
• Field of Search: 356/405, 356/406, 348/187-191, 358/518, 345/604, 345/639
• US Class Current: 356/405
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• CPC Class Codes: H04N 9/3182 Colour adjustment, e.g. white balance, shading or gamut white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607

Abstract

A color reproduction system includes a color conversion unit for displaying a color image on a multi-primary-color display. The color conversion unit includes a maximum brightness signal calculating unit for calculating signals corresponding to three color reproduction area corners as the corners of a plane that constitute a color reproduction area surface of the display. The three color reproduction area corners surround the vectors of input tristimulus values. The maximum brightness signal calculating unit also calculates a weighting factor obtained when the input tristimulus values are expressed as a linear sum of the tristimulus values of the color reproduction area corner vectors. The color conversion unit further includes a color image signal calculating unit for calculating a color image signal used to display the input tristimulus values, on the basis of the signals corresponding to the color reproduction area corners and the weighting factor. The color reproduction system can realize colorimetrically accurate reproduction, provide continuity between XYZ data and signal values, and use the color reproduction area to the maximum extent.

Claims

1. A color reproduction system having color image display means, arid color conversion means for converting input tristimulus values into a color image signal to be input to the color image display means, wherein the color conversion means comprises:

maximum brightness signal calculating means for calculating three color reproduction area corner vectors that indicate three corners of a plane constituting a color reproduction area surface of the color image display means, the three color reproduction area corner vectors surrounding vectors of the input tristimulus values, the maximum brightness signal calculating means also calculating a weighting factor obtained when the input tristimulus values are expressed as a linear sum of tristimulus values of the color reproduction area corner vectors; and

color image signal calculating means for calculating a color image signal used to display the input tristimulus values, on the basis of signal values corresponding to the color reproduction area corner vectors and the weighting factor.

3. A color reproduction system according to claim 1, further comprising profile data storage means storing profile data of the color image display means to be supplied to the color conversion means, the profile data including XYZ values obtained when each primary color is at its maximum emission and gradation characteristic data that provides a relationship between an input signal and emission brightness.

5. A color reproduction system according to claim 1, wherein the color image display means includes a plurality of projectors for creating and projecting an image based on the color image signal and formed of an optional number of primary colors, the number of the projectors being determined on the basis of a necessary number of colors, the projectors projecting images onto a single screen such that the projected images constitute a single image.

7. A color reproduction system according to claim 3, wherein the color image display means includes a plurality of projectors for creating and projecting an image based on the color image signal and formed of an optional number of primary colors, the number of the projectors being determined on the basis of a necessary number of colors, the projectors projecting images onto a single screen such that the projected images constitute a single image.

8. A color reproduction system according to claim 5, wherein the single screen is divided into a plurality of areas, and the number of the projectors is determined on the basis of a necessary number of colors in each of the areas, the projectors projecting images onto the respective areas of the single screen such that the projected images constitute a single image.

10. A color reproduction system according to claim 7, wherein emission spectra of the projectors distribute in a visible wavelength range of 380 nm-780 nm.

11. A color reproduction system according to claim 8, wherein emission spectra of the projectors distribute in a visible wavelength range of 380 nm-780 nm.

12. A color reproduction system according to claim 5, wherein emission spectra of the projectors distribute in a visible wavelength range of 380 nm-780 nm.

13. A color reproduction system according to claim 1, wherein the color image display means includes a CRT display or a liquid crystal display, which performs color reproduction by mixing primary color beams.

15. A color reproduction system according to claim 3, wherein the color image display means includes a CRT display or a liquid crystal display, which performs color reproduction by mixing primary color beams.

17. A color reproduction system according to claim 5, wherein the color image display means includes a CRT display or a liquid crystal display, which performs color reproduction by mixing primary color beams.

19. A color reproduction system according to claim 5, wherein the single screen has a projection surface which is at least one of flat, spherical, and curved.

2. A color reproduction system having color image display means, and color conversion means for converting input tristimulus values into a color image signal to be input to the color image display means, wherein the color conversion means comprises:

chromaticity area calculating means for calculating a chromaticity area surrounded by corners of planes constituting a color reproduction area surface of the color image display means;

matrix calculating means for calculating matrix data that provides a relationship between tristimulus values of the corners and the color image signal;

matrix data storage means for storing the matrix data in relation to the chromaticity area; and

color image signal calculating means for converting the input tristimulus values into the color image signal, using part of the matrix data selected on the basis of chromaticity values of the input tristimulus values.

4. A color reproduction system according to claim 2, further comprising profile data storage means storing profile data of the color image display means to be supplied to the color conversion means, the profile data including gradation characteristic data that provides a relationship between XYZ values obtained when each primary color is at its maximum emission, an input signal and emission brightness.

6. A color reproduction system according to claim 2, wherein the color image display means includes a plurality of projectors for creating and projecting an image based on the color image signal and formed of an optional number of primary colors, the number of the projectors being determined on the basis of a necessary number of colors, the projectors projecting images onto a single screen such that the projected images constitute a single image.

9. A color reproduction system according to claim 6, wherein emission spectra of the projectors distribute in a visible wavelength range of 380 nm-780 nm.

14. A color reproduction system according to claim 2, wherein the color image display means includes a CRT display or a liquid crystal display, which performs color reproduction by mixing primary color beams.

16. A color reproduction system according to claim 4, wherein the color image display means includes a CRT display or a liquid crystal display, which performs color reproduction by mixing primary color beams.

18. A color reproduction system according to claim 6, wherein the color image display means includes a CRT display or a liquid crystal display, which performs color reproduction by mixing primary color beams.

20. A color reproduction system according to claim 6, wherein the single screen is divided into a plurality of areas, and the number of the projectors is determined on the basis of a necessary number of colors in each of the plurality of areas, the projectors projecting images onto respective areas of the single screen such that the projected images constitute a single image.

21. A color reproduction system according to claim 4, wherein the color image display means includes a plurality of projectors which create and project an image based on the color image signal which is formed of primary colors, the number of the projectors being determined on the basis of a necessary number of colors, the projectors projecting images onto a single screen such that the projected images constitute a single image.

22. A color reproduction system according to claim 6, wherein the single screen has a projection surface which is at least one of flat, spherical, and curved.