  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.
