Patent ID: 7272249

Claim:
A fingerprint authentication method comprising, a first step of collating features of input data based on a fingeprint input by a user with features of enrolled data; a second step of judging whether the input data are proper for authentication or not, said judging comprising deciding an observation line on an input image; finding a pair of peak envelopes each of which links local maximums or local minimums on a graph of brightness against positions on the observation line; calculating discriminative values on the basis of the peak envelopes, said discriminative values representing features of the spatial distribution of the brightness; and deciding whether the input data are proper for the authentication or not on the basis of the discriminative values; and a third step of authenticating the input data according to results of said first step and said second step; wherein said second step is done on the basis of a spatial distribution of brightness in the input image represented by the input data.