An algorithm for accurately extracting the local fringe direction is presented. The algorithm estimates, in the neighborhood of n × n points, the direction of the gradient that points normal to the local fringe direction. The performance of four different derivative kernels is also compared. Since this method is sensitive to noise and variations in background and amplitude, a preprocessing step is used to limit these error sources. The method has been applied to the moiré deflectogram of a spherical and a progressive addition ophthalmic lens, resulting in a map of the refractive power of these lenses. The results are compared with the data obtained with a commercial focimeter. This technique is useful for analyzing the fringe patterns where the fringe direction is variable and must be obtained locally.

© 1998 Optical Society of America

[Optical Society of America ]

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

Related Journal Articles

• Intensity-Modulated Moiré Topography (AO)
• Improved regularized phase-tracking technique for the processing of squared-grating deflectograms (AO)
• Variational approach to moiré pattern synthesis (JOSAA)
• Digital Moiré Fringe-Scanning Method for Centering a Circular Fringe Image (AO)
• Accurate pixel-to-pixel correspondence adjustment in a digital micromirror device camera by using the phase-shifting moiré method (AO)

Related Conference Papers

• The Study on 3D Image Laser Sensing Technology of Welding Seam
• The Study on 3D Image Laser Sensing Technology of Welding Seam
• Stress Measurement of Al Film Deposited on Flexible Substrates by Shadow Moiré Method
• Optical System to Measure and Record 3D Profiles the Architectural Heritage Relief in Historic Buildings of Puebla City
• Correction of Discontinuous Phase Maps in Structured Light Perfilometry