Iris recognition systems typically take an image, like the one on the left, and use commercial software to convert it (as shown on the right) so it can be compressed to 3 kilobytes. National Institute of Standards and Technology researchers have determined an iris image compressed to 3 kilobytes provides enough detail to accurately recognize an individual's unique iris. That speeds processing images on remote databases.
The images are analyzed, measuring the many distinct angles that form in the intersecting lines and patterns that appear in the tissue of the iris. Those measurements create a unique signature that can be used to identify an individual.
Photo courtesy of NIST