A Method for Initial Guess Based on Multi-Level Grid Interpolation and Motion Characteristics Analysis for Digital Image Correlation

To reduce the computational load for Digital Image Correlation (DIC) measurement, this paper proposes a multi-level grid interpolation and motion characteristics analysis initial guess method. In an image, all subsets that need to be calculated are divided into multiple levels of grids. Based on the deformation parameters of low-level grid cells, the initial deformation parameters of higher-level grid cells can be estimated. In the image sequence of quasi-static material tests, the deformation parameters of the 0-level subsets in the next image can be estimated by analyzing the motion characteristics of those subsets. The proposed method is validated using images from the classic "DIC Challenge"[1]. The algorithm proposed in this paper can effectively improve the accuracy of overall initial value estimation, and improving the overall execution speed of the algorithm.