Color matching method, and image capturing device and electronic apparatus using the same

A color matching method for a digital image. Signals of a plurality of main colors in the digital image are extracted and the extracted signals are used to generate a 3×3 color matrix. The signals of the plurality of main colors are transformed into a 3×1 input matrix formed by the intensity of illumination, the color hue, and the color saturation of each of the color signals. An output value and color difference of the plurality of the color signals are recursively calculated by performing an iteration operation based on an equation composed of the color matrix, a predefined weighting matrix and a fine-tuning matrix, until the color difference is smaller than a predetermined threshold value.