Speeding up digital image correlation computation using the integral image technique

In recent years, with the requirement of high-resolution and real-time measurement, the computation speed of digital image correlation (DIC) has become increasingly important. At present, the DIC algorithms based on the iterative spatial domain cross-correlation algorithm are widely recognized as the most robust and rapid. In this paper, the integral image technique is extended to handle the complex items in the equations of the DIC algorithm in order to accelerate the calculation process. The influence of the interpolation method on the performance of the DIC algorithm is also investigated. In addition, the analysis of computational complexity and numerical experiment results are presented to illustrate the effectiveness of this method. The results successfully verify that the proposed method can improve the computation speed of the DIC algorithm greatly, and the improvement is more notable when the fast interpolation method is utilized.