1. A color interpolation method comprising: defining a pixel group of a matrix structure, having a pixel to be color-interpolated as a center pixel, in an image passed through a color filter of Bayer pattern and detected by an image sensor; determining whether an edge exists or not in the pixel group; interpolating a color of the center pixel using a low pass filter when an edge does not exist in the pixel group; and interpolating a color of the center pixel according to directivity of an edge when the edge exists in the pixel group.