1. A face recognition apparatus adapted to recognize an input face image on the basis of one or more registered face images, comprising: face image input means for inputting the face image to be recognized; Gabor filter application means for calculating the convolution of a pixel value at each feature value extraction position of the input image and coefficients of a Gabor filter defined by a Gabor function representing a spatial characteristic using a Gaussian function representing a window and a sine function or a cosine function representing a frequency response, for each of a predetermined set of frequency values and for each of a predetermined set of angles of the response function of the Gabor filter thereby determining a Gabor jet including as many scalar values as there are Gabor filters; similarity calculation means for calculating the similarity between a Gabor jet at each feature value extraction position of the input face image and a Gabor jet of a registered face image and determining a similarity vector whose elements are given by values indicating similarity at respective feature value extraction positions; and identify determination means for determining whether the input face image is identical to the registered face image, on the basis of the similarity vector, the Gabor filter application means including a filter window data ROM adapted to store values of the filter window determined by calculating the Gaussian function, sine data ROMs adapted to store values of the response function determined by calculating the sine function for the respective angles, cosine data ROMs adapted to store values of the response function determined by calculating the cosine function for the respective angles, and Gabor filter coefficient calculation means for calculating coefficients of the Gabor filter by multiplying the value read from the filter window data ROM and the values read from the sine data ROMs and the cosine data ROMs, the Gabor filter application means being adapted to calculate the convolution of the input face image and the Gabor filter coefficients calculated by the Gabor filter coefficient calculation means.