1. A color image processing method for correcting R, G, and B color signals output from an arbitrary image input device, comprising the sequential steps of: obtaining a model variable of a first transform matrix with respect to a selected all color samples; transforming the R, G and B output signals from said image input device with respect to the color samples into the color space value using the first transform matrix; and determining error characteristics based on the color space value transformed in said transforming step, dividing the color space into regions, and selecting a model of each region, calculating the variable value of a model, and storing the calculated value in a second transform matrix for each region.