Fingerprint authentication method, program and device capable of judging inexpensively whether input image is proper or not

A computer readable program for making a computer system serve as a finger authentication device, comprising:

• a first step of collating features of input data based on a fingerprint input by an user with features of enrolled data;
• a second step of judging whether the input data are proper for authentication or not;
• 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 by the use of a spatial frequency analysis of an input image represented by the input data.

A fingerprint authentication device comprising:

• a collating portion for collating features of input data based on a fingerprint input by an user with features of enrolled data;
• a characteristic judging portion for judging whether the input data are proper for authentication or not;
• and
• a authenticating portion for authenticating the input data according to outputs from said collation portion and said characteristic judging portion;
• wherein
• said characteristic judging portion uses a spatial frequency analysis of an input image represented by the input data to judge whether the input data are proper for authentication or not.