Open Access
ARTICLE
Phase-shifting Deflectometric Moiré Topography
Hongwei Guo1
1 Lab of Applied Optics and Metrology, Department of Precision Mechanical Engineering, Shanghai
University, Shanghai, China. Email Address: hw-guo@yeah.net
Structural Longevity 2011, 5(1), 39-47. https://doi.org/10.3970/sl.2011.005.039
Abstract
This paper presents a moiré-based technique for measuring the threedimensional shapes of specular surfaces. In it, a Ronchi grating is closely located
before the measured object and illuminated by diffusive light sources. When we
observe the measured object through this grating, moiré fringes are generated by
the superposition of this grating and its virtual image produced by the measured
specular surface. With this scheme, the movements of the grating along the vertical
direction introduce phase shifts in these moiré fringes so that their phases can be recovered by use of a self-calibrating phase-shifting algorithm. From the phases and
phase shifts, the three-dimensional shape of the specular surface is further reconstructed. Compared with the existing techniques, this method gives a promising
solution for measuring complex specular surfaces, because the measured objects
can be placed much closer to the grating. The validity of this technique has been
demonstrated by an experimental result.
Keywords
Cite This Article
Guo, H. (2011). Phase-shifting Deflectometric Moiré Topography.
Structural Longevity, 5(1), 39–47.