Investigating the accuracy of digital image correlation in monitoring strain fields across historical tapestries

Finite element generated synthetic image deformation is used to assess factors affecting the reliability and accuracy of strain fields measured by the DIC technique, when using the inherent historical tapestry image to track deformations. Compared with direct correlation with the reference image, incremental correlation is found to introduce accumulated error and is less suitable for DIC analysis under low strains. Image quality, for example, variation in resolution, is demonstrated to strongly affect DIC performance. Finally, it is recommended that an iterative approach is required to determine the optimum subset and strain filter size for effective DIC analysis using inherent tapestry patterns, especially at low strain levels.