2D Gabor transform profilometry by use of grid grating pattern and variable bandpass filters
2维载频条纹2维窗口傅里叶变换轮廓术

In order to increase measurement precision in Profilometry, reduce possible frequency overlaps and tolerate the height discontinuity of complex three-dimensional shape, an improved Profilometry using a grid carrier fringe pattern is presented. In the Profilometry, two spatial fringe patterns are perpendicular to each other to avoid frequency overlaps; two one-dimensional deformed grating patterns are separated from the deformed grid pattern by use of both two-dimensional Gabor transform and variable rectangle bandpass filters, from which the wrapped phases in x and y directions are respectively extracted. The corresponding unwrapped phases are achieved by use of a lookup table method. Compared with Profilometry using single frequency fringe pattern and one-dimensional double-frequency fringe pattern, the improved Profilometry could obtain double phase information of identical precision, increase measurement precision and realize discontinuous phase unwrapping. Detailed theoretical analysis is presented, and the simulated and experimental results show that it is feasible.