Since drying is a very slow process, a strong gradient of drying shrinkage occurs in concrete members leading, at the macroscopic level, to the rise of tensile stresses at the surface and compressive stresses at the core. Therefore, it may lead to superficial cracking. In addition, crossing cracks and/or debonding (at the interface with a substrate) may also occur in thin members if drying shrinkage is restrained. In order to study these phenomena, a new device based on digital image correlation (DIC) was setup. A post-processing tool is then proposed to capture the mapping of shrinkage strains and to determine the evolution of the cracking patterns. It was used successfully to observe, quantify and analyze cracking of a coating mortar, due to the restraint of drying shrinkage by a rigid substrate (concrete block).