Complementary Phase-Differencing Profilometry for Saturation-Induced Errors Suppression

Three-dimensional (3-D) measurement via fringe projection profilometry (FPP) is crucial in numerous industrial fields. However, high-reflective workpieces frequently result in saturated captured patterns, causing measurement to falter. Therefore, achieving saturation-induced errors suppression with convenience and high accuracy is a necessary requirement. In this article, a complementary phase-differencing profilometry (CPDP) is proposed to attain this breakthrough. By making use of the property of symmetry along the direct current (dc) component between the phase-shifting sinusoidal gratings and their corresponding complementary gratings, the proposed CPDP achieves mending of the oversaturated regions in the deformed patterns and effectively suppresses the saturation-induced errors. Furthermore, even if partial regions fail to completely mend oversaturation due to excessive overexposure, saturation-induced errors can also be suppressed effectively by the phase averaging between the corresponding complementary mended deformed patterns. The experimental results show that the proposed CPDP can achieve saturation-induced errors suppression with convenience and high accuracy and has prospective application in industrial high-reflective workpiece 3-D measurement.