Journal ArticleDOI
Automatic fringe analysis with a computer image-processing system
TLDR
The application of a general-purpose image-processing computer system to automatic fringe analysis is presented and three areas of application have been examined where the use of a system based on a random access frame store has enabled a processing algorithm to be developed to suit a specific problem.Abstract:
The application of a general-purpose image-processing computer system to automatic fringe analysis is presented. Three areas of application have been examined where the use of a system based on a random access frame store has enabled a processing algorithm to be developed to suit a specific problem. Furthermore, it has enabled automatic analysis to be performed with complex and noisy data. The applications considered are strain measurement by speckle interferometry, position location in three axes, and fault detection in holographic nondestructive testing. A brief description of each problem is presented, followed by a description of the processing algorithm, results, and timings.read more
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Optical image compression and encryption methods
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IV Advanced Evaluation Techniques in Interferometry
TL;DR: This chapter describes the advanced evaluation techniques in interferometry and identifies the types of error sources—namely, environmental errors, errors that are dependent on the method, and errors typically encountered in Interferometry.
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Digital Image Processing in Flow Visualization
TL;DR: A detailed review of classical flow visualization methods can be found in this article, where Merzkirch and Lauterborn & Vogel present a beautiful collection of pictures by Van Dyke.
References
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Journal Article
Digital wavefront measuring interferometer for testing optical surfaces and lenses
TL;DR: In this article, a self-scanned 1024 element photodiode array and a minicomputer are used to measure the phase (wavefront) in the interference pattern of an interferometer to lambda/100.
Journal ArticleDOI
Digital Wavefront Measuring Interferometer for Testing Optical Surfaces and Lenses
TL;DR: The system has been designed to optimize the collection of data to give higher than usual accuracy in measuring the individual elements and final performance of assembled diffraction limited optical systems, and furthermore, the short loop time of a few minutes makes the system an attractive alternative to constraints imposed by test glasses in the optical shop.
Journal ArticleDOI
Use of an ac heterodyne lateral shear interferometer with real-time wavefront correction systems.
TL;DR: An analysis shows that for uniform circular or square sources larger than a derived minimum size, the wavefront measurement accuracy depends only upon the radiance of the source and not upon the angular subtense of the sources.
Journal ArticleDOI
Image processing applied to the interactive analysis of interferometric fringes
TL;DR: A computer software system for performing interferometric fringe analysis interactively (FAI) based on a general-purpose image-processing system running on a DEC PDP-11 that permits manual definition of difficult fringe-pattern boundaries.
Journal ArticleDOI
An electro-optical read-out system for analysis of speckle photographs
TL;DR: An electro-optical read-out system for measuring displacement and strain fields from a double exposure speckle photograph is described in this article, where the optical system uses a cylindrical element to project the 1-D Fourier transform, with minimal distortion of the spacing of the fringe pattern.