Phase-error analysis and elimination for nonsinusoidal waveforms in Hilbert transform digital-fringe projection profilometry

Abstract

The nonlinear intensity response of a digital fringe-projection-profilometry (FPP) system causes the captured fringe patterns to be nonsinusoidal waveforms, which results in phase error and therefore measurement error. The theoretical analysis of the phase error due to the nonsinusoidal waveforms in Hilbert transform FPP is performed. Based on the derived phase-error expression, a cubic spline-smoothing method is proposed to eliminate the nonsinusoidal phase error. Experiments show that the proposed algorithm can be used for effective phase-error elimination in practical Hilbert transform FPP.