Each illumination base storage means (1) previously stores the illumination base (12) of the corresponding category representative. Each illumination direction estimating means (2) estimates the illumination direction (13) of an inputted face image (11) in which the error norm is a minimum value by using the illumination space base (12). Each error evaluation means (3) determines the inner product of the illumination base (12) and the corresponding illuminating direction (13) and calculates the error feature (14) which is the norm error between the determined inner product and the inputted face image (11). Category identifying means (40) determines the identification category (15) of the inputted face image (11) on the basis of the error feature (14).
FACE IMAGE CATEGORIZING METHOD, FACE IMAGE CATEGORIZING DEVICE, AND FACE IMAGE CATEGORIZING PROGRAM