Application of Digital Image Correlation Method Based on Genetic Algorithm in Micro-Displacement Measurement

Three integer pixel search algorithms of genetic algorithm, particle swarm optimization, and artificial fish swarm algorithm applied in the micro-displacement measurement arc studied and compared. The matching precision of the images is evaluated by the size of the correlation coefficient and the normalized cross-correlation function is selected as the correlation coefficient and the objective function of algorithms. The objective function is iteratively solved to obtain the micro-displacement result of the integer pixels. The simulated speckle pattern is taken as the research object, and the matching precision, searching speed, and micro-displacement measurement results for these three algorithms arc compared and analyzed. The results show that the genetic algorithm has obvious advantages in the matching precision, searching speed and micro-displacement measurement precision, which can meet the application requirements of the digital image correlation method in the micro -displacement measurement.