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US 6,549,653 B1Granted
Color image processing apparatus
AssigneeOlympus Optical Co., Ltd.
InventorsKenro Osawa, Nagaaki Ohyama, Masahiro Yamaguchi, Takashi Obi, Yuri Ohya
Life of this patent
Estimating the term…
Abstract
A color image processing apparatus for reproduces color data of a subject at higher accuracy by estimating the spectral reflectance of the subject from the color chip basis function vn (λ) which can expand the spectral reflectances of all color chips of the reference chart and the expansion coefficients B of the color chips. The color image processing aparatus uses an image processing device to which a subject shooting signal Q shot by the color image input device and a reference chart shooting signal G taken from a plurality of color chips each having a spectral reflectance is known.
Claims25
A color image processing apparatus comprising an image processing device for processing an input image signal of an object, in order to reproduce color data of the object, the image processing device further comprising:
- spectral reflectance calculating means including:
- a color chip shooting signal storage unit for calculating average values of shooting signal values corresponding to a plurality of color chips from a shooting image of a reference chart consisting of these color chips, for an appropriate region, and storing the average values as color shooting signals;
- a color chip expansion coefficient storage unit for storing expansion coefficients corresponding to basis functions of spectral reflectances of the color chips within the reference chart which are obtained in advance, as a first expansion coefficient;
- an object expansion coefficient calculating unit for calculating expansion coefficients of the object from an object shooting signal input from outside, a color chip shooting signal input from the color chip shooting signal storage unit, and the first expansion coefficients input from the color chip expansion coefficient storage unit;
- a color chip basis function storage unit for storing color basis functions vn(λ) (n=1 to 10);
- and
- a spectral reflectance calculating unit for calculating a spectral reflectance p(λ) of the object from the expansion coefficients of the object calculated by the object expansion coefficient calculating unit and the color basis functions vn(λ) (n=1 to 10) of the object output from the color basis function storage unit,
- which outputs obtained spectral reflectance p(λ);
- tristimulus values calculating means including:
- a color matching function data storage unit for storing color matching functions data in advance;
- and
- a tristimulus value operating unit for calculating tristimulus values XYZ under observation-site illumination for the object from the spectral reflectance p(λ) of the object, and observation-site illumination spectrum data S(λ) input from the observation-site illumination spectrum data storage unit provided outside;
- the tristimulus values calculating means outputting the tristimulus values XYZ;
- and
- RGB value calculating means including:
- a display device profile storage unit for storing characteristics data of the display device;
- and
- an output signal calculating unit for converting the tristimulus XYZ values into a display signals RGB, using the characteristics data of the display device;
- the RGB value calculating means outputting display signals RGB to the display device.
16 more elements
A color image processing apparatus for processing an input image signal of an object, in order to reproduce color data of the object, the apparatus comprising:
- color image input means for obtaining a color image signal of the object and a color image signal of a reference matter having a plurality of colors, in lighting for photographing;
- color estimating means for estimating the color data of the object from the color image signal of the object;
- and
- color image output means for reproducing the color image of the object based on the estimated color data of the object;
- wherein the color estimating means further comprises:
- matrix calculation means for calculating a matrix which provides a color image signal of the lighting for photographing, to a coefficient corresponding to a basis function of a spectral reflectance of the reference matter, by using the color image signal of the reference matter and the spectral reflectance of the reference matter;
- spectral reflectance calculation means for estimating a spectral reflectance of the object from the calculated matrix, the basis function of the spectral reflectance of the reference matter and the color image signal of the object;
- and
- color data calculating means for calculating color data of the object from the estimated spectral reflectance.
6 more elements
A color image processing apparatus for processing an input image signal of an object, in order to reproduce color data of the object, the apparatus comprising:
- color image input means for obtaining a color image signal of the object and a color image signal of a reference matter having a plurality of colors, in lighting for photographing;
- color estimating means for estimating the color data of the object from the color signal of the object;
- and
- color image output means for reproducing the color image of the object based on the estimated color data of the object;
- wherein the color estimating means further comprises:
- matrix calculation means for calculating a matrix which provides a color image signal in the lighting for photographing, to a coefficient corresponding to a basis function of a spectral reflectance of the reference matter, by using the color image signal of the reference matter, the spectral reflectance of the reference matter, and a basis function of a spectral reflectance of the object;
- spectral reflectance calculation means for estimating a spectral reflectance of the object from the calculated matrix, the basis function of the spectral reflectance of the reference matter and the color image signal of the object;
- and
- color data calculating means for calculating color data of the object from the estimated spectral reflectance.
6 more elements
A color image processing apparatus for processing an input image signal of an object, in order to reproduce color data of the object, the apparatus comprising:
- color image input means for obtaining a color image signal of the object in lighting for photographing and a color image signal of a reference matter having a plurality of colors in reference lighting for photographing;
- color estimating means for estimating the color data of the object from the color signal of the object;
- and
- color image output means for reproducing the color image of the object based on the estimated color data of the object,
- wherein the color estimating means further comprises:
- matrix calculation means for calculating a matrix which provides a color image signal in the lighting for photographing, to a coefficient corresponding to a basis function of a spectral reflectance of the reference matter, by using the color image signal of the reference matter, the spectral reflectance of the reference matter, a spectrum of the reference lighting for shooting, a basis function of a spectral reflectance of the object, and a spectrum of the lighting for photographing;
- spectral reflectance calculation means for estimating a spectral reflectance of the object from the calculated matrix, the basis function of the spectral reflectance of the reference matter and the color image signal of the object;
- and
- color data calculating means for calculating color data of the object from the estimated spectral reflectance.
6 more elements
Dependencies are inferred from the claim text.