Abstract

A direct correlation technique is used to calculate correlation fringe patterns from consecutive speckle patterns acquired with a dual-beam electronic speckle interferometer. Although more calculations are required than in standard image differencing routines, an advantage of the method is that the illumination over the surface of the object need not be uniform. In the method, Pearson’s coefficient of correlation between the intensities within a set of adjacent pixels is calculated. This has the added advantage of being directly related to the theoretical phase-dependent correlation. A mapping of this measure of correlation results in the correlation fringe pattern. Laboratory tests were carried out with in-plane translations ranging from 5 to 45 µm. The correlation calculations were carried out by using cells (square sets of pixels) in the raw speckle images with dimensions ranging from 2 pixels × 2 pixels to 19 pixels × 19 pixels. Both cell dimension and translation magnitude dependent decorrelation effects influence the quality of the correlation fringe patterns.

© 1997 Optical Society of America

Full Article  |  PDF Article

References

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
Login to access OSA Member Subscription

Cited By

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
Login to access OSA Member Subscription

Figures (10)

You do not have subscription access to this journal. Figure files 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
Login to access OSA Member Subscription

Equations (7)

You do not have subscription access to this journal. Equations 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
Login to access OSA Member Subscription

Metrics

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
Login to access OSA Member Subscription