Patent ID: 6072895
Filing Date: 2000-06-06
Classification: G06K

Abstract:
A computer system for imaging fingerprints, comprising:a computer having a user interface, a central processing unit (CPU), a disk storage that contains a plurality of data records representing one or more fingerprint images and an image capturing subsystem that produces an image of a target fingerprint;a feature extractor that produces one or more features from the target image, the features being minutiae of the target fingerprint, feature extraction being based on an angle--distance metric defined as a function of both locations and orientations of a minutiae pair, in accordance with the relationshipsD'=D2 * (1.0+A), andA=K*(difference (t1, (t.sub.2 +.pi.))) exp (J)where D2 is the regular Euclidean distance between the minutiae;t1 is the orientation of a first minutiae in radians;t2 is the orientation of a second minutiae in radians;the difference function evaluates an absolute value of the difference in orientation of the minutiae;K is in the range of 0.8 to 1.2;J is in the range of 1.0 to 2.0;and wherein minutiae pairs are not extracted if D' is below a predetermined value.