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Proceedings Paper

Modulated digital images for biometric and other security applications
Author(s): Lawry D. McCarthy; Robert A. Lee; Gerhard F. Swiegers
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Paper Abstract

There are, in general, two ways for an observer to deal with light that is incorrect in some way (e.g. which is partially out of focus). One approach is to correct the error (e.g. by using a lens to selectively bend the light). Another approach employs selective masking to block those portions of the light which are unwanted (e.g. out of focus). The principle of selective masking is used in a number of important industries. However it has not found widespread application in the field of optical security devices. This work describes the selective masking, or modulation, of digital images as a means of creating documents and transparent media containing overt or covert biometric and other images. In particular, we show how animation effects, flash-illumination features, color-shifting patches, information concealment devices, and biometric portraiture in various settings can be incorporated in transparent media like plastic packaging materials, credit cards, and plastic banknotes. We also demonstrate the application of modulated digital images to the preparation of optically variable diffractive foils which are readily customized to display biometric portraits and information. Selective masking is shown to be an important means of creating a diverse range of effects useful in authentication. Such effects can be readily and inexpensively produced without the need, for example, to fabricate lenses on materials which may not be conducive in this respect.

Paper Details

Date Published: 3 June 2004
PDF: 14 pages
Proc. SPIE 5310, Optical Security and Counterfeit Deterrence Techniques V, (3 June 2004); doi: 10.1117/12.528099
Show Author Affiliations
Lawry D. McCarthy, CSIRO (Australia)
Robert A. Lee, CSIRO (Australia)
Gerhard F. Swiegers, CSIRO (Australia)

Published in SPIE Proceedings Vol. 5310:
Optical Security and Counterfeit Deterrence Techniques V
Rudolf L. van Renesse, Editor(s)

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