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Proceedings Paper

Exploiting iris dynamics
Author(s): Charles Hsu; Harold Szu
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Paper Abstract

The human iris is a circular curtain over the light entrance pupil which is controlled directly by the intensity of blue light from photosensitive ganglions in the retina within the eye. The human iris dynamic is remarkable in that it is capable of shrinking concentrically along the radial direction by a factor 4 from 8mm to 2mm, and constantly oscillates in 1/2 second periodicity. Pupil dilation and contraction causes the iris texture to undergo nonlinear deformation with discrete components and minutia features. Thus, iris recognition must be scale invariant due to the pupil dynamics. We propose the Mandelbrot fractal dimension count of minutia iris details, at different intensity thresholds, in dilation-invariant wedge-boxes, formed at specific angular sizes, but spatially varying over 4 90° quadrants due to the cellular growth under the gravity. Despite the concentric dynamic, we have sought an invariant fractal dimensionality in the circular direction and discovered the non-isotropic effect, departed from the simple Richardson fractal law. Furthermore, we choose an optimum Rayleigh criterion λ/D matching the robust fine resolution scale for the given lens aperture D and the illumination wavelength λ for a potential application from a distant, with the help of comprehensive biometric including iris.

Paper Details

Date Published: 12 April 2010
PDF: 12 pages
Proc. SPIE 7703, Independent Component Analyses, Wavelets, Neural Networks, Biosystems, and Nanoengineering VIII, 770307 (12 April 2010); doi: 10.1117/12.855185
Show Author Affiliations
Charles Hsu, Trident Systems Inc. (United States)
Harold Szu, U.S. Army Night Vision & Electronic Sensors Directorate (United States)

Published in SPIE Proceedings Vol. 7703:
Independent Component Analyses, Wavelets, Neural Networks, Biosystems, and Nanoengineering VIII
Harold H. Szu; F. Jack Agee, Editor(s)

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