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Lecture 5: Iris Recognition. Ioannis Pavlidis. COSC 6397. U of H. Genotype and Phenotype. Genotype refers to a genetic constitution, or a group sharing it. blood group and DNA
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Lecture 5: Iris Recognition Ioannis Pavlidis COSC 6397 U of H
Genotype and Phenotype • Genotype refers to a genetic constitution, or a group sharing it. • blood group and DNA • Phenotype refers to the actual expression of a feature through the interaction of genotype, development, and environment. • face, fingerprint, and iris • Genotypic Error Rate is the minimum False Match Rate (e.g., identical twins). • Phenotypic Error Rate is the minimum False Rejection rate (e.g., facial appearance)
Properties of the Iris • The iris is composed of elastic connective tissue. • It consists of pectinate ligaments adhering into a tangled mesh revealing striations, ciliary processes, crypts, rings, furrows, a corona, sometimes freckles, and vasculature. • Pupillary motion provides a “live ness” test in high security applications.
Localization and Analysis of Iris Patterns • We localize the inner and outer boundaries of the iris. This is accomplished through integro-differential operations. • A normalized coordinate system is defined, which is invariant to size (e.g., camera zoom and distance to the eye). • The iris pattern is encoded into a 256-byte “IrisCode” by demodulating it with 2D Gabor wavelets, which represent the texture by phasors in the complex plane.
Independence and DOF in IrisCodes • It is important to establish that there exists independent variation in iris patterns, across populations and across positions in the iris. • This is confirmed by tracking the possibility of a bit being set. • The fact that the plot is flat at a value of 0.5 means that any given bit in an IrisCode is equally likely to be set or cleared.