Speckle Deformation Measurement Based on Pixel Correlation Search Method

Digital Image Correlation Method (DICM) is a non-contact deformation measurement method based on digital image processing technology and optical measurement methods. Because of its non-contact, high-precision, full-field and other advantages, it is widely used in civil engineering, aerospace and other fields. The whole-pixel correlation search method is a fast and high-precision deformation measurement method in DICM. This article first investigates the composition of the DIC measurement system, and studies the performance and unimodality of the shape function and related functions, and selects reasonable function model. Finally, the three whole-pixel search algorithms of point-by-point search method, hill-climbing method and differential evolution algorithm are experimentally analyzed. Finally, it is found that the performance of the hill-climbing method based on the zero mean normalized least square distance sum function is the best.