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Proceedings Paper

Frequency modulation of printed gratings as a protection against copying
Author(s): Sybrand Spannenburg
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Paper Abstract

A method for generating half-tone images on binary (i.e., paper and ink) systems using different (frequency-) modulation techniques is described. Security gratings and patterns are designed to generate 'alias' images or detectable codes, due to undersampling by the digital scanner.

Paper Details

Date Published: 1 October 1991
PDF: 17 pages
Proc. SPIE 1509, Holographic Optical Security Systems, (1 October 1991); doi: 10.1117/12.47113
Show Author Affiliations
Sybrand Spannenburg, J. Enschede en Zonen (Netherlands)


Published in SPIE Proceedings Vol. 1509:
Holographic Optical Security Systems
William F. Fagan, Editor(s)

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