Application of digital still camera to improve the extracting process of holographic vibration fringe pattern from interferogram

Abstract

As is well known, for vibration analysis of an object surface, holographic interferometry is one of the most efficient methods for noncontact measurement of microscopic displacement. For this purpose, the authors have developed a holographic pattern measuring system (HPMS) which can draw a 3D graphic image pattern of a vibrating surface. However, in the present HPMS, the fringe pattern data must be obtained manually with a digitizer, which consumes much time and is inefficient. In this study, to resolve this problem in the HPMS, the authors introduced a digital still camera to perform extraction accurately and improve the fringe pattern extraction process from the holographic interferograms.