Patent Document ID: 6072895
Application ID: 08823637
Patent Status: 1

Claim One:
1. 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 relationships D'=D2 * (1.0+A), and A=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.