Color conversion matrix creating device, color conversion matrix creating program, and image display apparatus

A computer-readable medium containing thereon a color conversion matrix creating program, which, when executed by a computer, causes the computer to:

• determine a first conversion matrix (MLCD) for color conversion between a color space of a display device and a reference color space;
• based on the first conversion matrix (MLCD), calculate first color values on the reference color space which correspond to predetermined colors on the color space of the display device;
• determine a second conversion matrix (Mtgt) for color conversion between a prescribed target color space and the reference color space;
• based on the second conversion matrix (Mtgt), calculate second color values on the prescribed target color space which correspond to the predetermined colors;
• based on the first color values and the second color values, determine third color values on a new target color space which correspond to the predetermined colors;
• based on the third color values, determine a third conversion matrix (Mnew) for color conversion between the new target color space and the reference color space;
• based on the first conversion matrix (MLCD) and the third conversion matrix (Mnew), determine a color conversion matrix (M) for color conversion between the color space of the display device and the new target color space;
• and
• determine a color adaptation correction matrix (Mcol) on the basis of a white point in the color space of the display device and a white point in the prescribed target color space;
• wherein the first conversion matrix (MLCD) is determined by using the color adaptation correction matrix (Mcol).

A color conversion matrix creating device, comprising:

• a first conversion matrix creating unit for determining a first conversion matrix (MLCD) for color conversion between a color space of a display device and a reference color space;
• a first calculating unit for, based on the first conversion matrix (MLCD), calculating first color values on the reference color space which correspond to predetermined colors on the color space of the display device;
• a second conversion matrix creating unit for determining a second conversion matrix (Mtgt) for color conversion between a prescribed target color space and the reference color space;
• a second calculating unit for, based on the second conversion matrix (Mtgt),calculating second color values on the prescribed target color space which correspond to the predetermined colors;
• an arithmetic unit for, based on the first color values and the second color values, determining third color values on a new target color space which correspond to the predetermined colors;
• a third conversion matrix creating unit for, based on the third color values, determining a third conversion matrix (Mnew) for color conversion between the new target color space and the reference color space;
• and
• a color conversion matrix creating unit for, based on the first conversion matrix (MLCD) and the third conversion matrix (Mnew), determining a color conversion matrix (M) for color conversion between the color space of the display device and the new target color space;
• wherein
• the predetermined colors on the color space of the display device are RGB colors;
• the reference color space is the XYZ color space;
• the first, second and third values are xy chromaticity values;
• and
• the arithmetic unit is configured to determine the third values by using the following equations:
• Rnewx=R0x*a+R1x*(1−a)
• Rnewy=R0y*a+R1y*(1−a)
• Gnewx=G0x*a+G1x*(1−a)
• Gnewy=G0y*a+G1y*(1−a)
• Bnewx=B0x*a+B1x*(1−a)
• Bnewy=B0y*a+B1y*(1−a)
• where
• Rnewx, Rnewy are the third color values for color R,
• Gnewx, Gnewy are the third color values for color G,
• Bnewx, Bnewy are the third color values for color B,
• R0x, R0y are the second color values for color R,
• G0x, G0y are the second color values for color G,
• B0x, B0y are the second color values for color B,
• R1x, R1y are the first color values for color R,
• G1x, G1y are the first color values for color G,
• B1x, B1y are the first color values for color B, and
• a is a matching coefficient.

A color conversion matrix creating device, comprising:

• a first conversion matrix creating unit for determining a first conversion matrix (MLCD) for color conversion between a color space of a display device and a reference color space;
• a first calculating unit for, based on the first conversion matrix (MLCD), calculating first color values on the reference color space which correspond to predetermined colors on the color space of the display device;
• a second conversion matrix creating unit for determining a second conversion matrix (Mtgt) for color conversion between a prescribed target color space and the reference color space;
• a second calculating unit for, based on the second conversion matrix (Mtgt), calculating second color values on the prescribed target color space which correspond to the predetermined colors;
• an arithmetic unit for, based on the first color values and the second color values, determining third color values on a new target color space which correspond to the predetermined colors;
• a third conversion matrix creating unit for, based on the third color values, determining a third conversion matrix (Mnew) for color conversion between the new target color space and the reference color space;
• and
• a color conversion matrix creating unit for, based on the first conversion matrix (MLCD) and the third conversion matrix (Mnew), determining a color conversion matrix (M) for color conversion between the color space of the display device and the new target color space;
• wherein
• the predetermined colors on the color space of the display device are RGB colors;
• the reference color space is the XYZ color space;
• the first, second and third values are color values in the LCh colorimetric system;
• and
• the arithmetic unit is configured to determine the third values by using the following equations:
• Rnewc=R0x*a+R1x*(1−a)
• Rnewh=R0h*a+R1h*(1−a)
• Gnewh=G0c*a+G1c*(1−a)
• Gnewh=G0h*a+G1h*(1−a)
• Bnewc=B0c*a+B1c*(1−a)
• Bnewh=B0h*a+B1h*(1−a)
• where
• Rnewc, Rnewh are the third color values for color R,
• Gnewc, Gnewh are the third color values for color G,
• Bnewc, Bnewh are the third color values for color B,
• R0c, R0h are the second color values for color R,
• G0c, G0h are the second color values for color G,
• B0c, B0h are the second color values for color B,
• R1c, R1h are the first color values for color R,
• G1c, G1h are the first color values for color G,
• B1c, B1h are the first color values for color B, and
• a is a matching coefficient.