A method for improving quality of DSPI measurement

Digital speckle pattern interferometry (DSPI) has a wide variety of useful applications but suffers from speckle noise that cannot be easily removed using conventional filtering. We study a method by which the contrast of speckle interference fringes may be enhanced, thus improving the measurement quality of DSPI. The results demonstrate both improved the fringe contrast and an improvement in the quality of the speckle fringes by reduction of the speckle noise is. When combined with a phase-stepping algorithm, the quality of the DSPI measurement is significantly improved. Finally, the measurement results of deformation using contrast enhancement also show improvement when compared with conventional filtering.