1. A color interpolation apparatus for processing a plurality of image pixels corresponding to a color filter array to reconstruct missing color components for each image pixel having a single color component, the color interpolation apparatus comprising: an edge detection circuit for detecting edges in a plurality of interpolating directions for a target image pixel and then generating a plurality of edge indicators respectively corresponding to the interpolating directions, the edge detection circuit determining an edge indicator for an interpolating direction by summing absolute values of a first color difference and a second color difference and then determining the edge indicator for the interpolating direction by normalizing a sum of the absolute values with a stochastic adjustment factor for normalizing standard deviations of the interpolating directions, the first color difference being between color components of a first image pixel in the interpolating direction and a second image pixel in another interpolating direction opposite to the interpolating direction, the second color difference being between color components of a third image pixel in the interpolation direction and the target image pixel, the color components of the first and second image pixels being identical to the missing color component of the target image pixel, the color component of the third image pixel being identical to the color component of the target image pixel; and an interpolation circuit, coupled to the edge detection circuit, for reconstructing at least a missing color component of the target image pixel according to a plurality of neighboring image pixels respectively in the interpolating directions and the edge indicators of the interpolating directions, each of the neighboring image pixels having a color component identical to the missing color component.