Employment of predictive search algorithm in digital image correlation

A predictive search algorithm to estimate the size and direction of displacement vectors was presented. The algorithm decreased the time of calculating the displacement of each pixel. In addition, the updating reference image scheme was used to update the reference image and to decrease the computation time when the displacement was larger than a certain number. In this way, the search range and computational complexity were cut down, and less EMS memory was occupied. The capability of proposed search algorithm was then verified by the results of both computer simulation and experiments. The results showed that the algorithm could improve the efficiency of correlation method and satisfy the accuracy requirement for practical displacement measuring.