An image processing device includes: a color polarized light acquisition unit (101) containing a single-plate color imaging element having a color mosaic filter (201) and a patterning polarizer (202) formed by a plurality of polarizer units having different-angle transmission polarization planes and arranged in a plurality of pixels of the same color (G) in the color mosaic filter (201); a polarization information processing unit (103) which approximates the relationship between the luminance of the light which has passed through the polarizer unit in the G pixels and the angle of the transmission polarization plane of the polarizer unit by a sine function; and a color mosaic interpolation unit (103) which interpolates the color luminance so as to obtain a color luminance that cannot be obtained in the target pixel and generates a color luminance image.
