In a high precision image processor and image processing program, an output of a one-chip Bayer array CCD is A/D converted and noise reduced, and then entered in a G interpolation circuit which comprises interpolation circuit B which implements interpolation processing of a less resolving power but does not reflect on the result of interpolation an apparent sensitivity difference occurring at a pixel value of a G pixel of the one-chip CCD, and interpolation circuit A which implements interpolation processing of an improved resolving power but reflects an apparent sensitivity difference on the result of interpolation. G interpolation circuit estimates a sensitivity difference at a pixel of interest and combines outputs of interpolation circuits A and B such that for a large sensitivity difference, the output of circuit B is used more, and for a small sensitivity difference, the output of circuit A is used more.