Digital image correlation for small strain measurement in deformable solids and geomechanical structures

Digital image correlation (DIC) is a well-known contact-less technique offering highly accurate full-field deformation measurement using grayscale images. The practical implementation of DIC is still facing many challenges, especially limitations of accuracy in measuring small displacement gradients for solids in geosciences and biomedi-cal engineering. In this paper, we introduce a novel approach in which color images are employed to enhance the performance of DIC. A complete framework for Color DIC has been proposed and tested. The results show that Color DIC performs significantly better than grayscale DIC for measurement of small strains by a factor of 2.