The sub-pixel searching algorithm based on gradient in digital speckle correlation method

摘要

Digital speckle correlation method (DSCM) is an successful nondestructive testing technique for the whole displacements. The computational accuracy is a challenging issue. In this paper, a new gradient-based method is proposed, the accuracy of the method is demonstrated via three computed-simulated speckle image pairs. Combining the method with radial basis function interpolation, two experimentally obtained deformation fields are measured.