Abstract of Thesis Performance Analysis of 3-dimensional Fingerprint Scan System

OF THESIS PERFORMANCE ANALYSIS OF 3-DIMENSIONAL FINGERPRINT SCAN SYSTEM Fingerprint recognition has been extensively applied in both forensic law enforcement and security involved personal identification. Traditional fingerprint acquisition is generally done in 2-D, with a typical automatic fingerprint identification system (AFIS) consisting of four modules: image acquisition, preprocessing, feature extraction, and feature matching. In this thesis, we present a technology of noncontact 3-D fingerprint capturing and processing for higher performance fingerprint data acquisition and verification as the image acquisition and preprocessing models, and a new technology of unraveling the 3D data to 2D fingerprint. We use NIST fingerprint software as the feature extraction and feature matching models. Our scan system relies on a novel real-time and low-cost 3-D sensor using structured light illumination (SLI) which generates both texture and detailed ridge depth information. The high resolution 3-D scans are then converted into 2-D unraveled equivalent images, using our proposed best fit sphere unravel algorithm. As a result, many limitations imposed upon conventional fingerprint capturing and processing are relaxed by the unobtrusiveness of the system and the extra depth information obtained. In addition, expect for the small distortions that may be caused by camera and projector, compared to the techniques used nowadays, the whole process defuses distortion, and the unraveled fingerprint is controlled to 500 dots per inch. The image quality is evaluated and analyzed using NIST fingerprint image software. A comparison is performed between the converted 2-D unraveled equivalent fingerprints and their 2-D ink rolled counterparts. Then, NIST matching software is applied to the 2-D unraveled fingerprints, and the results are given and analyzed, which shows strong relationship between matching performance and quality of the fingerprints. In the end, some incremental future works are proposed in order to make further improvements to our new 3D fingerprint scan system.