Digital speckle image correlation method base on particle swarm optimization algorithm

In order to get the integer pixel displacement information and the sub-pixel displacement information simultaneously at one time, the sub-pixel subarea was constructed by using the method of gray interpolation and the digital image correlation method based on particle swarm optimization algorithm was proposed. The applicability of the method was verified by measuring both the simulated speckle pattern with the translational information and with the strain information. And then, the integer pixel particle swarm algorithm and the sub-pixel of different magnitude interpolation gray particle swarm algorithm were compared by measuring the specimen with tiny rotational displacement. The results show that the particle swarm algorithm based on sub-pixel digital scattered spot image correlation method has advantages for small displacement measurement.