A polarization image acquisition unit (11) acquires polarization images of three or more polarization directions. A feature quantity computation unit (15) computes image feature quantities on the basis of the acquired polarization images. For example, the luminance of each polarization image is normalized for each pixel, and the normalized luminance of the polarization image is used as the image feature quantity. The luminance of the polarization image changes according to the surface shape of an object. Thus, the image feature quantities computed on the basis of the polarization images are feature quantities corresponding to the surface shape of the object. Image processing, for example, image recognition, feature point detection, feature point matching, or the like, can be performed on the basis of the surface shape of the object using such image feature quantities.