Wavelet transform analysis of truncated fringe patterns in 3-D surface profilometry

Gorthi, Sai Siva and Lolla, Kameswara Rao (2005) Wavelet transform analysis of truncated fringe patterns in 3-D surface profilometry. In: Optical Measurement Systems for Industrial Inspection IV, Monday 13 June 2005, Bellingham, WA.

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Abstract

Wavelet transform analysis of projected fringe pattern for phase recovery in 3-D shape measurement of objects is investigated. The present communication specifically outlines and evaluates the errors that creep in to the reconstructed profiles when fringe images do not satisfy periodicity. Three specific cases that give raise to non-periodicity of fringe image are simulated and leakage effects caused by each one of them are analyzed with continuous complex Morlet wavelet transform. Same images are analyzed with FFT method to make a comparison of the reconstructed profiles with both methods. Simulation results revealed a significant advantage of wavelet transform profilometry (WTP), that the distortions that arise due to leakage are confined to the locations of discontinuity and do not spread out over the entire projection as in the case of Fourier transform profilometry (FTP).

Item Type:	Conference Paper
Publisher:	SPIE--The International Society for Optical Engineering
Additional Information:	Copyright of this article belongs to SPIE--The International Society for Optical Engineering.
Keywords:	Wavelet Transform;Fringe Projection;Surface Profile;FTP; Leakage Effect;phase demodulation;WTP.
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	02 Mar 2012 06:46
Last Modified:	02 Mar 2012 06:46
URI:	http://eprints.iisc.ac.in/id/eprint/43737

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