"Uniaxial three-dimensional shape measurement with projector defocusing," Opt. Eng., (2012)

Y. Xu* and S. Zhang, "Uniaxial three-dimensional shape measurement with projector defocusing," Opt. Eng. 51(2) 023604, 2012; doi: 10.1117/1.OE.51.2.023604

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.