Saturation-Induced Phase Error Compensation Method Using Complementary Phase

Abstract

Intensity saturation can induce phase error and, thus, measurement error in fringe projection profilometry. To reduce saturation-induced phase errors, a compensation method is developed. The mathematical model of saturation-induced phase errors is analyzed for N-step phase-shifting profilometry, and the phase error is approximately N-folder of the frequency of the projected fringe. Additional N-step phase-shifting fringe patterns with initial phase-shift π/N are projected for generating a complementary phase map. The final phase map is obtained by averaging the original phase map extracted from the original fringe patterns and the complementary phase map, and then the phase error can be canceled out. Both simulations and experiments demonstrated that the proposed method can substantially reduce the saturation-induced phase error and realize accurate measurements for a highly dynamic range of scenarios.

Adaptive chessboard-like high-frequency projection method for three-dimensional measurement of shiny surfaces

“…Tan et al [12] theoretically analyzed the saturated signal model, deduced the periodic characteristic of saturation-induced phase error, and designed a saturated phase error correction method based on Fourier analysis and the Hilbert transform. Wan et al [13] propose a saturation error compensation method based on complementary phase to reduce the phase error due to saturation. The essence of the method is to make an imprecise guess based on experience, and it works well when the target surface complies with experience.…”