Patent ID: 7965417

Claim:
A method of generating a tone correction table used to correct tone characteristics of image data of each component color in a color image forming apparatus, the method comprising: using a processor to perform: an output step of outputting color patch images of each component color for respective tone levels corresponding to a plurality of different image data values; a colorimetry step of acquiring colorimetric values including brightness values, chromatic values, and reflection spectra of respective patches by measuring colors of the output color patch images; an analysis step of analyzing characteristics of the colorimetric values for respective tone levels based on the colorimetric values of the color patch images; a selection step of selecting a tone correction table generation method according to the characteristics obtained in the analysis step; and a generation step of generating a tone correction table to have tone characteristics as target characteristics according to the selected tone correction table generation method, wherein the selection step calculates the numbers of absorption peaks from the spectral reflection spectra, selects the tone correction table generation method based on the numbers of absorption peaks, and uses, as the tone correction table generation method, at least any of the brightness values, the chromatic values, and color difference values calculated from the brightness values and the chromatic values.