ABSTRACT
This chapter determines some of the design criteria for the different parts of a system that can perform digital processing of interferograms (DPI). Interferometric techniques are widely used for quantitative measurements of flow fields and/or properties of transparent fluids. In order to make such an evaluation, however, an accurate analysis of interferograms has to be done. When a DPI system is used in an experiment, it should be regarded as a measuring instrument and designed accordingly. The configuration of the system is strictly related to the application to which it is oriented. The digitization of an image starts by transducing point by point the light intensity into an electrical signal by means of an electro-optical sensing device. The image, acquired by a sensor, has to be digitized before it is processed. Digitization of video signals is achieved by means of special hardware whose core is the analog—digital converter.
