1. A color interpolation method for correcting color values of an image, comprising the steps of: constructing a color interpolation matrix having a plurality of points and a center point as an interpolation point, where each point being expressed by one known color and two unknown colors; correcting the known color value of the center point as a function of the color values of the center point and the points in the matrix having the same known color; choosing the horizontal direction or the vertical direction with respect to the center point as the benchmark direction for interpolation calculation; and interpolating one or more unknown color values of the center point as a function of the known color values of the points in the benchmark direction and the known color value of the center point.