The ever-increasing requirements of product quality and reliability demand more efficient measuring and testing methods. Developed in the past decade, shearography--also called speckle pattern shearing interferometry--is a coherent-optical measuring and testing method, similar to holographic interferometry. This book describes the development of second-generation digital shearography, which is especially effective in nondestructive testing, strain measurement, and vibration analysis due to its relative insensitivity to environmental disturbances.