An optical scanning and recognition system is used in conjunction with a matching system to enable efficient authentication for secure spaces and devices. Like other finger scanning technologies, electro-optical fingerprint recognition makes it possible to quickly and accurately compare a given fingerprint image to thousands of stored images.
Electro-optical fingerprint scanners are generally designed to be portable, easy to use, and physically rugged. The devices are becoming more widely used as an alternative to passwords for consumer electronics or as part of a two-factor authentication system where more stringent security is required.
The fingerprint is optically scanned directly from the finger and the resulting image is focused onto a small chip. The chip converts the focused image into a digital file that can be processed, stored, and compared with other fingerprint images.
The high-resolution digital images can be processed like any other scanned images, eliminating problems caused by aliasing (also called jaggies) and making it possible to quickly compare a fingerprint image with other fingerprint images in a large database.
The digital image obtained by such scanning is called a "finger image". In some texts, the terms fingerprinting and fingerprint are used, but technically, these terms refer to traditional ink-and-paper processes and images.
Fingerscanning is a biometric process, because it involves the automated capture, analysis, and comparison of a specific characteristic of the human body.
There are several different ways in which an instrument can bring out the details in the pattern of raised areas (called ridges) and branches (called bifurcations) in a human finger image.
The most common methods are optical, thermal, and tactile. They work using visible light analysis, heat-emission analysis, and pressure analysis, respectively.
Biometric fingerscanning offers improvements over ink-and-paper imaging. A complete set of fingerscans for a person (10 images, including those of the thumbs) can be easily copied, distributed, and transmitted over computer networks.
In addition, computers can quickly analyze a fingerscan and compare it with thousands of other fingerscans, as well as with fingerprints obtained by traditional means and then digitally photographed and stored. This greatly speeds up the process of searching finger image records in criminal investigations.