Patent ID: 6549653
Filing Date: 2003-04-15
Classification: G09G,H04N

Abstract:
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(&lgr;) (n=1 to 10); and a spectral reflectance calculating unit for calculating a spectral reflectance p(&lgr;) of the object from the expansion coefficients of the object calculated by the object expansion coefficient calculating unit and the color basis functions vn(&lgr;) (n=1 to 10) of the object output from the color basis function storage unit, which outputs obtained spectral reflectance p(&lgr;); 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(&lgr;) of the object, and observation-site illumination spectrum data S(&lgr;) 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.