Color expressing method, color image reading apparatus and color image processing apparatus

摘要

A color image reading system in which an input color image signal is converted into color data signals. The color data signals are indicative of a combination of data of reference stimuli represented by vertices of a triangle of which one side circumscribes a pure purple locus, and of which the remaining two sides circumscribes two points of a spectral locus of a color degree diagram, the two points representing substantially middle colors between a color represented by one vertex of the triangle at which the remaining two sides intersect and each of two colors represented by the remaining two sides of the triangle, respectively. The input color image signal is reproduced on a color image output device in response to the provision of the color data signals.