title: Contactless optical scanning of fingerprints with 180 degrees view.
abstract: Fingerprint recognition technology is an integral part of criminal investigations. It is the basis for the design of numerous security systems in both the private and public sectors. In a recent study emulating the fingerprinting procedure with widely used optical scanners, it was found that, on average, the distance between ridges decreases about 20% when a finger is positioned on a scanner. Using calibrated silicon pressure sensors, the authors scanned the distribution of pressure across a finger, pixel by pixel, and also generated maps of the average pressure distribution during fingerprinting. Controlled loading of a finger demonstrated that it is impossible to reproduce the same distribution of pressure across a given finger during repeated fingerprinting procedures. Based on this study, a novel method of scanning the fingerprint with more than a 180 degrees view was developed. Using a camera rotated around the finger, small slices of the entire image of the finger were acquired. Equal sized slices of the image were processed with a special program assembling a more than 180 degrees view of the finger. Comparison of two images of the same fingerprint, namely the registered and actual images, could be performed by a new algorithm based on the symmetry of the correlation function. The novel method is the first contactless optical scanning technique to view 180 degrees of a fingerprint without moving the finger. In a machine which is under design, it is expected that the full view of one finger would be acquired in about a second.
authors.affiliation: Advanced Electronic Technology Center, Electrical and Computer Engineering Department, University of Massachusetts, Lowell, Massachusetts 01854, USA.
authors.forename: J
authors.initials: J
authors.lastname: Palma
authors.forename: C
authors.initials: C
authors.lastname: Liessner
authors.forename: S
authors.initials: S
authors.lastname: Mil'shtein
mesh_terms: D000465:Algorithms; D001699:Biometry; D003878:Dermatoglyphics; D001330:Electronic Data Processing / Q000379:methods*; D006801:Humans; D011312:Pressure; D015203:Reproducibility of Results; D012825:Silicon
chemical_list: D012825:Silicon