COLOR CORRECTION PARAMETER COMPUTATION METHOD, COLOR CORRECTION PARAMETER COMPUTATION DEVICE, AND IMAGE OUTPUT SYSTEM

摘要

A color correction parameter computation method includes: obtaining first color-signal values respectively corresponding to colors of color patches and obtained by photographing a color chart having the patches thereon, and reference color-signal values respectively defining the colors of the patches; computing, for each color of the patches, a color difference component between the first and the reference color-signal values; selecting at least one color of the patches by comparing the magnitude of the difference components; computing a color correction parameter using the first and the reference color-signal values corresponding to the selected color; computing an accuracy measure using the difference component between a second corrected color-signal value obtained by correcting a first color-signal value corresponding to a color other than the selected color and the reference color-signal value defining the color other than the selected color; and determining correction accuracy by comparing the accuracy measure to an accuracy criterion.

主权项

1. A color correction parameter computation method comprising:
step (a) of obtaining a plurality of first color signal values that respectively correspond to colors of a plurality of color patches and are obtained by photographing a color chart having the color patches on a surface, and a plurality of reference color signal values respectively defining the colors of the color patches; step (b) of computing, for each one of the colors of the color patches, a color difference component between a corresponding one of the first color signal values and a corresponding one of the reference color signal values; step (c) of selecting at least one color of the color patches based on comparison of magnitude of the color difference components obtained in the step (b); step (d) of computing a color correction parameter using the first color signal value corresponding to the selected color and the reference color signal value that defines the selected color, the color correction parameter being a parameter that makes the color difference component between a first corrected color signal value which is obtained by correcting the first color signal value corresponding to the selected color using the color correction parameter and the reference color signal value defining the selected color smaller than the color difference component between the first color signal value corresponding to the selected color and the reference color signal value defining the selected color; step (e) of computing a measure of accuracy using the color difference component between a second corrected color signal value which is obtained by correcting a first color signal value corresponding to a color other than the selected color using the color correction parameter and the reference color signal value that defines the color other than the selected color; and step (f) of determining accuracy of correction by comparing the measure of accuracy to a predetermined accuracy criterion.