The major phases in the iris pattern recognition process include iris scan for image acquisition, iris localization for distinguishing the iris from the rest of the eye, feature extraction, and template creation, followed by matching. Daugman’s approach uses 256-byte IrisCode as a template and performs matching applying XOR operations on the IrisCodes. All commercial applications currently implement Daugman’s patented techniques.
John Daugman of Cambridge University later developed the algorithms, mathematical methods, and techniques to encode iris patterns and efficiently compare them. Ophthalmologists Leonard Flom and Arin Safir first noted the distinctive features of iris and described methods for iris recognition in 1987. This stable uniqueness of iris texture becomes the basis of iris-based biometric recognition. The iris’s complex structure carries distinctive information, and under normal health conditions, it remains unchanged from early childhood to death of the individual. This uniqueness holds in family siblings, and even identical twins, where other genetic details such as facial appearance are so similar. Not only the iris patterns are unique for each individual, but irises of left and right eyes of the same individual are also unique. Each iris is unique, and even irises of identical twins are different. Iris is the visible ring on the front side of the eye that surrounds the pupil of one’s eye.
