A Method of Separating Interreflection in Digital Fringe Projection Profilometry

Optical 3D surface measurement techniques, such as Fringe Projection Profilometry (FPP), are commonly used methods for reconstructing object surfaces. However, when traditional FPP is applied to measure regions involving interreflection, the measured phase can be distorted, leading to reduced accuracy in 3D shape measurement or even measurement failure. In this study, we propose to employ high-frequency binary masks to modulate phase-shifting and Gray code patterns and eliminate the interreflection among object surfaces. Experimental results demonstrate that this method can effectively separate direct and indirect illumination and suppress interreflection to enhance the accuracy of 3D object measurement.