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Optical Engineering

System response to automated grid methods
Author(s): James S. Sirkis
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Paper Abstract

Digital image processing and pattern recognition have become important tools in experimental stress analysis. Fringe interpretation and digital autocorrelation are the two prominent examples where digital image processing has significantly influenced experimental research. This paper discusses the use of digital image processing in concert with the grid method. Presented here is a start-to-finish analysis of grid point tracking with image acquisition hardware and pattern recognition software. A mathematical model, which is based on experimentally controllable parameters, is used to simulate the video camera and analog-to-digital conversion. A simple centroid algorithm is used to track the grid points. The model results, which are reaffirmed by rigid body motion tests, show that the fill factor, signal-to-noise ratio, and grid spot diameter govern the accuracy of this automated grid method. Finally, the model shows that the intensity profile of the individual grid spots has a significant impact on the maximum allowable grid frequency, camera field of view, and the overall accuracy of automated grid methods.

Paper Details

Date Published: 1 December 1990
PDF: 9 pages
Opt. Eng. 29(12) doi: 10.1117/12.55751
Published in: Optical Engineering Volume 29, Issue 12
Show Author Affiliations
James S. Sirkis, Univ. of Maryland (United States)


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