Dynamic phase extraction in phase-shifted shearography

Phase-shifted shearography needs to extract dynamic phase of the measured object after loading, so an algorithm for dynamic phase extraction in phase-shifted shearography is proposed to analyze the speckle patterns with random phase shifts. By using correlation method, the fringe patterns with random phase shifts are obtained from the speckle patterns with random phase shifts. Then the dynamic phase distributions are extracted from one set of random phase-shifted fringe patterns by principle component analysis. The experimental results show that the extracted phases are accurate and efficient. The proposed method is non-iterative and has no strict requirement for the spatial-carrier frequency of fringe patterns, so it is suitable for dynamic shearing speckle interferometry.