What Are the Different Types of Iris Recognition Systems?

Iris recognition systems are devices that scan an individual's irises in order to establish the individual's identity, usually for security purposes. Such systems are based primarily on the use of cameras that use infrared light to generate highly-detailed images of the unique patterns in an individual's iris. Iris recognition systems are used in a variety of different settings, including immigration control, airport security, and even in lieu of passwords for sites on the Internet. Security systems based in iris recognition are, when used correctly, at least as effective as fingerprint scanners for identifying individuals without ambiguity. Also, upon developing a template for recognizing an individual, there is seldom any need to update that template during the individual's lifetime.

The components used in different iris recognition systems may differ according to the quality and application of the systems. They might, for instance, use either infrared or visible light when generating images. The generated images are run through algorithms that are subjected to complex mathematical analysis in order to conclusively verify an individual's identity. The algorithms and mathematical methods used vary based on the type and quality of the optical device used to collect the image of the individual's iris. Some iris recognition systems are immobile while others are handheld devices, which are often networked to an external database containing user templates.

Infrared or visible light can be used in iris recognition systems. The systems based in near infrared light, or NIR, are the most common because near infrared light does not generate reflections that can make iris recognition difficult. Unfortunately, the NIR images lack any pigment coloration information, so recognition algorithms must rely entirely on patterns unrelated to color. Iris recognition based in visible light picks up pigmentation, so recognition systems are able to make use of color patterns, which can make identification much easier because pigmentation patterns contain a great deal of information that can be used for recognition. Visible light reflections in these systems, however, can result in a substantial amount of noise in the collected images.

Many iris recognition systems are combined with other biometric identification systems or other methods of identification verification for added security. The chances of a combined fingerprint and iris identification system being bypassed are quite small, particularly if some alternate identification, such as a passport or password, is also required. Other systems, however, rely entirely on iris recognition systems because they have very low potential for erroneous identification.