EVALUATION OF A SCALE-SPACE FILTER FOR SPECKLE NOISE-REDUCTION IN ELECTRONIC SPECKLE PATTERN INTERFEROMETRY

Recently, the application of a scale-space filter for speckle noise re duction in electronic speckle pattern interferometry correlation fring es was reported. The filter, derived from information theory and stati stical mechanics considerations, is an iterative, adaptive, and cluste ring algorithm that performs edge-preserving smoothing. To apply the f ilter, the kernel size and the number of iterations must be previously set. We show that both parameters can be chosen depending on image fe atures, e.g., presence or absence of sharp edges due to shadows, holes , or physical limits of the test object. When high-contrast edges are present, it is also shown that better noise reduction and edge preserv ation are obtained when the convergence of the solution of the filter is truncated. Both computer-simulated and experimental correlation fri nges are used to test the scale-space filter. (C) 1998 Society of Phot o-Optical Instrumentation Engineers.