Abstract
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Electronic speckle pattern interferometry (ESPI) is a nondestructive, whole-field optical measurement
technique. The removal of speckle noise is fundamental to extract measurement information accurately.
In this letter, two filtering methods based on the oriented feature of ESPI fringes, i.e., the second-order
oriented partial differential equation (SOOPDE) and oriented, regularized quadratic-cost function filtering
methods, are first proven to be consistent. An important question in solving partial differential equation,
i.e., how to select suitable parameters in an adaptive manner, is then discussed. The computer-simulated
and experimentally obtained ESPI fringe patterns and phase map are processed by the SOOPDE filtering
model with adaptive selective parameters. The qualitative and quantitative analyses demonstrate that the
parameters selected by the adaptive method are effective and suitable for the SOOPDE filtering model.