Method for creating color conversion definition for image output devices and image processing apparatus implementing the method

A method for creating a color conversion definition which converts an input color in an input color space to an output color in a color space of an image output device, the method comprising the successive steps of:

• (a) selectively inputting a first illumination light and a second illumination light;
• (b) setting a mixing ratio between the first illumination light and the second illumination light;
• (c) using a mixed illumination light of the first illumination light and the second illumination light in an observational environment based on the set mixing ratio;
• (d) determining color values of a device color of the image output device in the observational environment under the mixed illumination light;
• and
• (e) creating the color conversion definition on the basis of the determined color values of the device color of the image output device,
• wherein the color conversion definition reduces the difference between the input color and the output color observed under the first illumination light and under the second illumination light compared with the difference between the input color and the output color in a case where the input color is converted to the output color in an observational environment under the second illumination light using a color conversion definition created on the basis of measured color values of a device color of the image output device determined in an observational environment under the first illumination light.

An image processing apparatus for creating a color conversion definition which converts an input color in an input color space to an output color in a color space of an image output device, comprising:

• a lighting unit which uses a mixed illumination light of the first illumination light and the second illumination light in an observational environment to observe an output result of the image output device;
• a determining unit which determines color values of a device color of the image output device in the observational environment under the mixed illumination light;
• and
• a color conversion definition creating unit which creates a color conversion definition on the basis of the determined color values of the device color of the image output device,
• wherein the color conversion definition reduces the difference between the input color and the output color observed under the first illumination light and under the second illumination light compared with the difference between the input color and the output color in a case where the input color is converted to the output color in an observational environment under the second illumination light using a color conversion definition created on the basis of measured color values of a device color of the image output device determined in an observational environment under the first illumination light.

An image processing apparatus for creating a color conversion definition which converts an input color in an input color space to an output color in a color space of an image output device, the image processing apparatus comprising:

• an input unit which selectively inputs the first illumination light and the second illumination light;
• a setting unit which sets a mixing ratio between the first illumination light and the second illumination light;
• a lighting unit which uses a mixed illumination light of the first illumination light and the second illumination light in an observational environment based on the set mixing ratio;
• a determining unit which determines color values of a device color of the image output device in the observational environment under the mixed illumination light;
• and
• a color conversion definition creating unit which creates the color conversion definition on the basis of the determined color values of the device color of the image output device,
• wherein the color conversion definition reduces the difference between the input color and the output color observed under the first illumination light and under the second illumination light compared with the difference between the input color and the output color in a case where the input color is converted to the output color in an observational environment under the second illumination light using a color conversion definition created on the basis of measured color values of a device color of the image output device determined in an observational environment under the first illumination light.