The Electronic Speckle Pattern Interferometry (ESPI) is a widely used technique for measurement displacement and deformation. But the fringe phase pattern of ESPI always comes with large noise when using phase-shifting technique. In order to ensure the accuracy of the measurement, it is very important to eliminate the noise of the phase fringe pattern. This paper introduced a phase filtering method, comparing with traditional methods, which can be found is a simple and effective method, and the experimental results have shown that the method was feasible used for image processing of ESPI fringes．
Electronic speckle pattern interferometry for fracture expansion in nuclear graphite based on PDE image processing methods
