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Proceedings Paper

Speckle contrast dithering simulations
Author(s): G. H. Sendra; Hector Jorge Rabal; Marcelo Trivi; Ricardo A. Arizaga
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Paper Abstract

Algorithms used to process a speckle image are limited by the resolution of the CCD camera and the employed digitalization system. We propose the use of dithering procedures to increase the intensity discrimination and improve the contrast resolution. This technique consists in decreasing the quantification error by performing several measurements to which a random value is added in each measurement before detection. Hence, it is possible to find a more approximated value to the real one. The precision increase results from the use of multiple images to which a determined white-light intensity has been added. This work shows the results of applying dithering to improve the precision of methods that use speckle contrast. It is a frequently used quantity in the implementation of activity images and in the determination of surface roughness. Numerically simulated images were used to verify the reliability of the technique whose intensities were later quantified for processing. The observed mean squared error is lower when this technique is employed, and the level of improvement depends on the size of the used windows. A device for the experimental verification of the results is in the design stage.

Paper Details

Date Published: 21 October 2004
PDF: 5 pages
Proc. SPIE 5622, 5th Iberoamerican Meeting on Optics and 8th Latin American Meeting on Optics, Lasers, and Their Applications, (21 October 2004); doi: 10.1117/12.591754
Show Author Affiliations
G. H. Sendra, Univ. Nacional de Mar del Plata (Argentina)
Hector Jorge Rabal, Ctr. de Investigaciones Opticas (Argentina)
Univ. Nacional de La Plata (Argentina)
Marcelo Trivi, Ctr. de Investigaciones Opticas (Argentina)
Univ. Nacional de La Plata (Argentina)
Ricardo A. Arizaga, Ctr. de Investigaciones Opticas (Argentina)
Univ. Nacional de La Plata (Argentina)


Published in SPIE Proceedings Vol. 5622:
5th Iberoamerican Meeting on Optics and 8th Latin American Meeting on Optics, Lasers, and Their Applications
Aristides Marcano O.; Jose Luis Paz, Editor(s)

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