Robust Shape Measuring System to Noise for Measuring Micro Deformation

In this paper, a precise 3D shape measurement system applicable to industrial fields is configured by extracting phase information from a fringe image. The fringe image, which has deformation information about an object, is a time difference image of the interference images produced by projecting coherent laser light to the surface of an object. The phase information about a surface deformation is extracted from a single fringe image. In this paper, a band-pass filter in the frequency domain is used to efficiently extract a phase image from a fringe image with noise of wideband frequency spectrum. We tested the practical use of this system by measuring the deformation shape of a tensile specimen in a mechanical vibrating field.