Ray-based phase error correction for miniaturized DOE projector-based FPP under single-directional hyperbolic projection

Fringe Projection Profilometry (FPP) systems using miniaturized DOE pro-jectors often suffer from severe phase artifacts due to nonlinear projection characteristics and limited pattern controllability. We propose a ray-based phase error correction framework that models phase artifacts along projection rays from the projector pinhole, incorporating projector geometry without re-lying on image-domain processing or neighboring pixels. A projector pinhole estimation method based on a single-directional hyperbolic fringe pattern is introduced, through which projector geometry can be recovered without stereo calibration. In addition, a data-efficient strategy constructs the re-finement model from a single calibration pose. Experiments on miniaturized DOE projector-based FPP systems demonstrate significant improvements in reconstruction accuracy under nonlinear projection conditions, confirming the robustness and physical consistency of the proposed approach.

Quasi-calibration method for structured light system with auxiliary camera

The structured light projection technique is a representative active method for 3-D reconstruction, but many researchers face challenges with the intricate projector calibration process. To address this complexity, we employs an additional camera, temporarily referred to as the auxiliary camera, to eliminate the need for projector calibration. The auxiliary camera aids in constructing rational model equations, enabling the generation of world coordinates based on absolute phase information. Once calibration is complete, the auxiliary camera can be removed, mitigating occlusion issues and allowing the system to maintain its compact single-camera, single-projector design. Our approach not only resolves the common problem of calibrating projectors in digital fringe projection systems but also enhances the feasibility of diverse-shaped 3D imaging systems that utilize fringe projection, all without the need for the complex projector calibration process.