Color processing apparatus and method
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Suzuki
Life of this patent
Estimating the term…
Abstract
In order to calculate the calorimetric value of a color patch under a given viewing illuminant, a plurality of colorimetric value sets obtained by measuring the colors of color patches under a plurality of illuminants are stored in a memory, the type of spectral distribution and white point information of the viewing illuminant are obtained (S12), and a calorimetric value set corresponding to the type of spectral distribution of the viewing illuminant is selected (S13). A colorimetric value set under the viewing illuminant is calculated from the selected calorimetric value set, on the basis of the white point information of the viewing illuminant and the white point information of the illuminant of the selected colorimetric value set (S14).
Claims7
A color processing apparatus, comprising:
- a memory for storing a plurality of colorimetric value sets, each of which is associated with a type of spectral distribution and white point information;
- an obtaining section, arranged to obtain a type of spectral distribution and white point information of a viewing illuminant;
- a selector, operable to select a colorimetric value set corresponding to the type of spectral distribution of the viewing illuminant from the plurality of colorimetric value sets stored in the memory;
- and
- a calculator, arranged to convert the selected colorimetric value set into a converted colorimetric value set based on the white point information of the viewing illuminant and the white point information of an illuminant of the selected colorimetric value set;
- wherein, when color temperature of the illuminant of the selected colorimetric value set is not identical with that of the viewing illuminant, the calculator calculates a colorimetric values set under the viewing illuminant from the converted colorimetric value set based on the color temperature of the viewing illuminant and the color temperature of the illuminant of the selected colorimetric value set so as to output the colorimetric value set under the viewing illuminant, and
- wherein, when the color temperature of the illuminant of the selected colorimetric value set is identical with that of the viewing illuminant, the calculator outputs the selected colorimetric value set as the colorimetric value set under the viewing illuminant.
A method of a color processing comprising;
- using a processor to perform the steps of:
- storing a plurality of colorimetric value sets, each of which is associated with a type of spectral distribution and white point information, in a memory;
- obtaining a type of spectral distribution and white point information of a viewing illuminant;
- selecting a colorimetric value set corresponding to the type of spectral distribution of the viewing illuminant from the plurality of colorimetric value sets stored in the memory;
- converting the selected colorimetric value set into a converted colorimetric value set based on the white point information of the viewing illuminant and the white point information of an illuminant of the selected colorimetric value set;
- calculating, when color temperature of the illuminant of the selected colorimetric value set is not identical with that of the viewing illuminant, a colorimetric values set under the viewing illuminant from the converted colorimetric value set based on the color temperature of the viewing illuminant and the color temperature of the illuminant of the selected colorimetric value set so as to output the colorimetric value set under the viewing illuminant;
- and
- outputting the selected colorimetric value set as the colorimetric value set under the viewing illuminant when the color temperature of the illuminant of the selected colorimetric value set is identical with that of the viewing illuminant.
Dependencies are inferred from the claim text.