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I.E.E.E. Trans. on Pattern Analysis and Machine Intelligence 15 (1993), pp. 1148-1161.

High Confidence Visual Recognition of Persons
By a Test of Statistical Independence

John G. Daugman

University of Cambridge

Abstract

A method for rapid visual recognition of personal identity is described, based on the failure of a statistical test of independence. The most unique phenotypic feature visible in a person's face is the detailed texture of each eye's iris: an estimate of its statistical complexity in a sample of the human population reveals variation corresponding to several hundred independent degrees-of-freedom. Morphogenetic randomness in the texture expressed phenotypically in the iris trabecular meshwork ensures that a test of statistical independence on two coded patterns originating from different eyes is passed almost certainly, whereas the same test is failed almost certainly when the compared codes originate from the same eye. The visible texture of a person's iris in a real-time video image is encoded into a compact sequence of multi-scale quadrature 2-D Gabor wavelet coefficients, whose most-significant bits comprise a 256-byte ``iris code." Statistical decision theory generates identification decisions from Exclusive-OR comparisons of complete iris codes at the rate of 4,000 per second, including calculation of decision confidence levels. The distributions observed empirically in such comparisons imply a theoretical ``cross-over" error rate of one in 131,000 when a decision criterion is adopted that would equalize the False Accept and False Reject error rates. In the typical recognition case, given the mean observed degree of iris code agreement, the decision confidence levels correspond formally to a conditional False Accept probability of one in about .


Index Terms - Image analysis, statistical pattern recognition, biometric identification, statistical decision theory, 2-D Gabor filters, wavelets, texture analysis, morphogenesis.

• Introduction
• Image Analysis
  • Operators for Locating an Iris
  • Assessing Image Quality, Eyelid Occlusion, and Possibility of Artifice
  • Two-Dimensional Gabor Filters
  • Doubly Dimensionless Projected Polar Coordinate System
• Code Construction and Entropy Measures
  • The 256-Byte Iris Code
  • Commensurability of Iris Codes
  • Bitwise Entropy and Iris Variation
  • Number of Independent Degrees-of-Freedom in an Iris Code
• Statistical Decision Theory
  • Neyman-Pearson Formalism
  • Strategies and Decidability
• Performance
  • Database
  • Imposters' Hamming Distances
  • Authentics' Hamming Distances
  • Equivalent Bernoulli Trials
  • Decision Confidence Levels
  • Ergonomics, Robustness to Noise, and Imaging Factors
  • Speed of Decision Making
• Conclusion
• References
• About this document ...

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