Patent ID: 8072647

Claim:
A color conversion apparatus for converting first image data to second image data, the first and second image data both describing an image with a plurality of picture elements (pixels), the first image data including first color data with three values per pixel, the three values expressing, respectively, red, green, and blue color components of the pixel, the three values having ranges extending beyond a range from 0% to 100% in each of the red, green, and blue color components, the second image data including second color data with three values per pixel expressing, respectively, the red, green, and blue color components of the pixel, the color conversion apparatus comprising: a characteristic information calculator for calculating characteristic information of the first color data, the characteristic information including brightness or saturation; a first hue region data generator for calculating, from the first color data, a plurality of first hue region data values valid in respective hue regions surrounding certain predetermined hues; a second hue region data generator for using the characteristic information to adjust magnitudes of the plurality of the first hue region data values to obtain second hue region data values and third hue region data values; a gamut information detector for detecting a gamut of colors of the first image data and outputting gamut information representing the detected gamut of colors; a coefficient generator for generating matrix coefficients for the second and third hue region data values with reference to the gamut information; and a matrix operation calculator for deriving the second color data by performing a matrix operation including multiplication of the second and third hue region data values by the matrix coefficients.