0
DEFLECTOMETRY

Fourier transform method for automatic processing of moire´ deflectograms

[+] Author Affiliations
Juan Antonio Quiroga, Daniel Crespo, Eusebio Bernabeu

Universidad Complutense, Departamento de O´ptica, Facultad de Ciencias Fi´sicas, 28040?Madrid, Spain

Opt. Eng. 38(6), 974-982 (Jun 01, 1999). doi:10.1117/1.602138
History: Received Sep. 17, 1998; Revised Nov. 30, 1998; Accepted Dec. 4, 1998
Text Size: A A A

Abstract

In this work, a Fourier transform technique for automatic analysis of moire´ deflectograms is presented. A squared grating is used to multiplex the information of the deflection in two orthogonal directions in one image. This procedure avoids the necessity of rotating the gratings to obtain the complete deflection information. With this method only two fringe patterns, reference and distorted, are needed to determine the complete deflection information. To deal with irregularly shaped processing areas, a Gerchberg extrapolation method is used. The automatic determination of the carrier as well as the size and position of the reconstruction windows permit the complete and automatic measurement of the deflection produced by an ophthalmic lens in two orthogonal directions. Afterwards, the refractive power maps can be obtained. Experimental results obtained with a progressive addition lens are presented and comparison with measurements obtained with a commercial focimeter are shown showing a good agreement. © 1999 Society of Photo-Optical Instrumentation Engineers.

© 1999 Society of Photo-Optical Instrumentation Engineers

Citation

Juan Antonio Quiroga ; Daniel Crespo and Eusebio Bernabeu
"Fourier transform method for automatic processing of moire´ deflectograms", Opt. Eng. 38(6), 974-982 (Jun 01, 1999). ; http://dx.doi.org/10.1117/1.602138


Access This Article
Sign In to Access Full Content
Please Wait... Processing your request... Please Wait.
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
 
Your Session has timed out. Please sign back in to continue.
Sign In to Access Full Content

Figures

Tables

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

PubMed Articles
Advertisement


Buy this article ($18 for members, $25 for non-members).
Sign In