Contents I. Introduction
In THE PAST decade, optical 3-D shape measurement systems have been gaining an increasing importance in numerous fields of activities, ranging from the first reverse engineering applications requiring the acquisition of canonical surfaces up to other areas as diverse as industry, health, space exploration, and cultural heritage, to name a few. Today, the industry is very attracted by the possibilities given by the inspection of products performed by optical measurement systems [1]–[3], which capture shape data from surfaces in the form of clouds of points. The contactless inspection of manufactured goods has been successful in different areas, such as the automotive industry, semiconductor inspection, food, and pharmaceuticals manufacturing, where the goal of reducing production costs can be achieved by saving manual labor and limiting defective parts, thus ensuring a consistent product quality. Optical 3-D shape measurement systems can also allow manufacturers to check goods (silicon wafers, semiconductor chips, or surfaces of painted vehicles) one by one for defects, with the aim of controlling the parameters of the industrial process as soon as a defect is found. On the other hand, the current tendency evolves toward the use of scanners in the reconstruction of human faces, sculptures, paintings, prehistorical footprints, etc. The key to their success can be found in their distinctive attributes. Indeed, flexibility, reliability, higher operating speeds, consistency, and objectivity have made them competitive with respect to traditional measurement systems.
