An improvement of digital speckle correlation method using the predictive search algorithm

The discrepancy of precision and rate is still an obvious drawback of the Digital Speckle Correlation Method (DSCM), using a single camera, though it has been widely used for measuring the full-field displacement and surface strain field. What limits the use of DSCM in real-time system is its tremendous computational complexity. The predictive search algorithm presented can effectively estimate the magnitude and direction of displacement vectors and decrease the amount of calculation in a sense. In the way, the predictive search algorithm sharply speeds up the efficiency of DSCM without any loss of measurement accuracy. The capability of proposed search algorithm is verified by experiments. The results show that the algorithm can improve the efficiency of correlation method and also satisfy the need of measuring in-plane displacements in accuracy.