1. An image processing apparatus for processing an image, comprising: a face detector for detecting a face image of a subject contained in a captured image, based on image information of the captured image supplied from an imaging unit; a face feature detector for detecting a face feature contained in the face image, based on image information of the face image detected by the face detector; a normalizer for normalizing the face image detected by the face detector, based on a detected position of the face feature detected by the face feature detector and generating a normalized face image; and a face expression detector for detecting a face expression contained in the face image, based on image information of the normalized face image generated by the normalizer.