Fingerprint recognition system

Abstract

A method of analyzing and recognizing fingerprint images that utilizes vector processing of a vector field that is defined as the tangential vector of the fingerprint ridge curves is disclosed. The raw fingerprint image is divided into blocks, filtered to remove noise, and the orientation direction of each block is found. This allows the ridge curves to be enhanced and approximated by piece-wise linear approximations. The piece-wise linear approximations to the ridge curves allow the minutiae to be extracted and classified and a fingerprint minutiae template to be constructed. An enrollment process gathers multiple fingerprint images, creates fingerprint minutiae templates corresponding to the acquired fingerprint images, and stores the templates and other data associated with the respective individual or the enrolled fingerprint in a fingerprint database. In an identification process, an unknown raw fingerprint image is obtained via a fingerprint scanner and processed similarly to the enrollment process such that the fingerprint minutiae template of the unknown fingerprint is compared to one or more previously enrolled fingerprint minutiae templates. The identity of the individual associated with the unknown fingerprint is thereby ascertained. In addition, live finger detection can be accomplished in conjunction with the verification or identification process through analysis of the fingerprint image thus enhancing the security of the overall system.

1 . A method for fingerprint recognition, the method comprising the steps of: 
 acquiring a fingerprint image;    dividing the fingerprint image into blocks, thereby forming a blocked fingerprint image;    separating the blocked fingerprint image into foreground blocks and background blocks;    determining an orientation angle and amplitude for each of the foreground blocks, thereby forming an orientation field of the fingerprint;    creating a ridge-enhanced image of the fingerprint;    creating a binary image of the fingerprint;    creating a piecewise linear image of the fingerprint;    extracting minutiae of the fingerprint from the piecewise linear image of the fingerprint;    creating a fingerprint template of the fingerprint from the extracted minutiae; and    storing the fingerprint template as an enrolled fingerprint template.