A probability density function model describing height estimation uncertainty due to image pixel intensity noise in digital fringe projection measurements

• Published in: Optics and lasers in engineering Vol. 138; no. C; p. 106422
• Main Authors: O’Dowd, Niall M., Wachtor, Adam J., Todd, Michael D.
• Format: Journal Article
• Language: English
• Published: United Kingdom Elsevier Ltd 01.03.2021; Elsevier
• Subjects: Digital fringe projection; Height estimation; Pixel intensity noise; Uncertainty quantification; Uncertainty quantification; Pixel intensity noise; Digital fringe projection; Height estimation
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2020.106422

•A model is presented describing fringe-projected height error arising from measurement phase error.•A closed form solution is presented for the specific case of pixel intensity noise.•The model is validated using Monte-Carlo simulation and arbitrary correlation.•The model is further validated using an experimental digital fringe projection system. Digital fringe projection is a surface-profiling technique used for highly accurate non-contact measurements. As with any measurement technique, a variety of sources degrade to the measurement accuracy of the method. This paper presents an analytically-derived probability density function that explicitly models the surface height measurement error due to inevitable phase measurement error, and it includes the specific case of pixel noise inducing the phase measurement error that ultimately leads to the height estimation error. The accuracy of the model was validated through Monte-Carlo simulations of resultant height distributions subject to arbitrarily correlated pixel intensity noise and experimental digital fringe projection measurements where the pixel-by-pixel height uncertainty estimations were compared to the predictions of the derived model.