“…The DSCM is suited for samples with a planar surface and not any curved surface, which will cause a significant error or measurement deviation [21,22]. DSPI, originally called as electronic speckle pattern interferometry (ESPI) [23,24], is considered as the most reliable technique for measuring microscopic deformation and strain [25,26,27,28,29,30,31], and many scholars have applied the DSPI technology to measure the strain in many fields [32,33,34].…”