摘要
The improved Fourier transform profilometry(IFTP) and phase-shifting profilometry(PSP) are typical phase calculation methods in 3D optical phase measurement.The PSP has a high ability of anti-noise,but the projective grating needs a spatial frequency as high as possible,so that the wrapped phase results in superposition due to undersampling.IFTP expands measuring range,but the loss of high frequency component in the wrapped phase would cause a fast change of phase.Considering the advantages and disadvantages of IFTP and PSP,a new algorithm which combines the two methods is proposed to improve the accuracy of phase calculation.The simulation and experimental results demonstrate that this algorithm possesses better anti-noise performance.By means of this method,a better result for phase calculation is obtained over IFTP and PSP.
The improved Fourier transform profflometry (IFTP) and phase-shifting profilometry (PSP) are typical phase calculation methods in 3D optical phase measurement. The PSP has a high ability of anti-noise, but the projective grating needs a spatial frequency as high as possible, so that the wrapped phase results in superposition due to undersampling. IFTP expands measuring range, but the loss of high frequency component in the wrapped phase would cause a fast change of phase. Considering the advantages and disadvantages of IFTP and PSP, a new algorithm which combines the two methods is proposed to improve the accuracy of phase calculation. The simulation and experimental results demonstrate that this algorithm possesses better anti-noise performance. By means of this method, a better result for phase calculation is obtained over IFTP and PSP.
基金
supported by the Science Fund of Yunnan Province,China (No.2007F028M)
the Fund of Education Committee,Yunnan Province(No.07L00003)