Uniaxial three-dimensional shape measurement with projector defocusing

Our study shows that the phase error caused by improperly defocused binary structured patterns correlates to the depth z. This finding leads to a novel uniaxial three-dimensional shape measurement technique without triangulation. Since the measurement can be performed from the same viewing angle, this proposed method overcomes some limitations of the triangulation-based techniques, such as the problem of measuring deep holes. Our study explains the principle of the technique and presents some experimental results to verify its feasibility. (c) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.2.023604]