Multi-Mode Biometrics for Law Enforcement Operations

Abstract

Fingerprinting is the most extensively used biometrics supported by biggest database compared to other biometrics, such as retina imaging, face or voice recognition and others. However fingerprinting image could be distorted by pressure of the finger against the scanner, therefore needs to be contactless. Most important, distances between ridges on a finger depend on physical conditions (health) of an individual. That is when map of blood vessels in a finger is very helpful and supportive information. In addition, police criminal investigators do find some time not standalone fingerprint but images of few fingers or even image of a palm. In current study, we report a new design and test results of c o n t a c t l e s s line scan hardware, which produces images of single nail-to-nail finger, four fingers together, and image of human palm. The major focus of the study is development of high-resolution images of blood vessels and the new algorithm based on linear filtering neighborhood analysis, which generates a well-defined and interconnected blood vessel map. The new position of I R light sources provides a good and mostly uniform contrast between the veins and surrounding tissues. This configuration is different from the conventional positioning, where all three objects are aligned along vertical axis, that is, the source of light positioned above the tested finger, and the camera is located below the finger. The new experimental imaging configuration and blood vessel tracking algorithm could be combined with contactless fingerprinting to reinforce biometric personal identification.