3-D Imaging of surfaces for industrial applications: integration of structured light projection, Gray code projection and projector-camera calibration for improved performance

In this paper, two measurement procedures, aimed at the improvement of the performance of an optical whole field profilometer based on grating projection, are presented. The first procedure is based on the Gray code method. It performs a space encoding of the measurement area and yields 3-D range images in which even sharp discontinuities of the object shape can be measured. The second procedure performs the calibration of the optical components of the system, in order to describe the 3-D profile in a global coordinate system, and limiting the use of a reference surface only during the calibration of the profilometer. In the paper, the two procedures are detailed and some interesting experimental results are reported

Three-dimensional imaging based on gray-code light projection: characterization of the measuring algorithm and development of measuring system for industrial applications

A three-dimensional ͑3-D͒ imaging system based on Gray-code projection is described; it is thought to be used as an integration to the already developed profilometer based on the projection of multifrequency gratings. The Gray-code method allows us to evaluate the 3-D profile of objects that present even marked discontinuities of the surface, thus increasing the flexibility of the measuring system as to the topology of the objects that can be measured. The basic aspects of Gray-code projection for 3-D imaging and profiling are discussed, with particular emphasis devoted to the study of the resolution of the method and to the analysis of the systematic errors. The results of this study allow us to determine the optimal setting of the parameters of the measurement and to develop a suitable calibration procedure. The procedures for implementing the Gray-code method are presented, and some interesting experimental results are reported. Calibration of the system reveals an accuracy of 0.2 mm, corresponding to 0.1% of the field of view

Religioni e democrazia nel processo di globalizzazione

Il contributo illustra il ruolo delle religioni nel processo di globalizzazione, con particolare riferimento alla "globalizzazione" del sistema democratico