Large depth-of-field 3D measurement with multi-view fusion in MEMS-based structured light field

Fringe projection profilometry (FPP) is widely used in industrial metrology and 3D scanning. However, relying on traditional lens-based imaging mechanism, existing FPP systems face challenges in achieving high-precision measurement over large depth range. To overcome this limitation, this paper presents an approach integrating micro-electro-mechanical system (MEMS) projection with light field imaging (LFI). To accurately characterize the projection-imaging relationship across a large depth of field (DOF), an extended depth ray fusion model (EDRFM) is proposed, utilizing ray tracing to unify the representation of both projection and imaging processes. Furthermore, phase consistency ensures spatial alignment across multiple viewpoints, and a fusion method incorporating the angle between projection-camera rays and phase modulation quality is introduced to reduce errors caused by view variations. Experimental results demonstrate that the proposed method achieves a measurement accuracy of 0.12 mm within a 650 mm depth range.