A contouring approach using single grating digital shadow moire with a phase stepping technique

A digital shadow moire technique is applied to obtain surface contours by a dopting the concept of digital speckle pattern interferometry (DSPI) phase- shifting methods. The idea is based on the fact that the mathematical expre ssions of the resulting moire patterns mathematically resembles those of th e DSPI methods. Consequently, by grating shifting it is possible to obtain phase maps using the same DSPI algorithms. A brief theoretical approach is outlined and experimental results, performed under white light illumination , are shown.