FPGA-based fringe projection with double light intensity via bidirectional scanning

Fringe projection profilometry (FPP) is a high-precision, non-contact measurement technique. The quality of 3D reconstruction largely depends on the projection quality and the number of phase shifts and frequencies. Traditional MEMS projection methods project fringes only during the forward scan, limiting projection light intensity as they do not utilize the reverse scan. To address this, a high-quality fringe projection system is developed using an FPGA and a uniaxial MEMS scanning mirror. The method projects 8-bit fringe patterns based on angle interval signals and uses both forward and reverse scans. By projecting patterns in both directions and reversing the forward pattern during the backward scan, the projection light intensity is effectively doubled compared to unidirectional methods. This bidirectional scanning approach projects the same pattern during both the forward and backward scans, doubling light intensity and improving the Signal-to-Noise Ratio (SNR) of captured images, thus enhancing the reconstruction accuracy of the MEMS-based system.