SC-FPP: breaking 1 kHz frame-rate limits of 3D reconstruction with industrial cameras via snapshot compressive fringe projection profilometry

Fringe projection profilometry (FPP) is constrained by the synchronization mechanism of projector-camera pairs, limiting its application in high-spatiotemporal-resolution scenarios, such as additive manufacturing molten pool monitoring and dynamic testing. Specifically, the 3D reconstruction frame rate of FPP is limited by the camera transmission bandwidth and the length of projection sequence required for unambiguous phase retrieval: an f Hz industrial camera typically achieves up to only f/P Hz 3D imaging (P is the projection sequence length). This frame-rate loss restricts industrial monitoring to ∼100 Hz. To address the problem, we propose the snapshot compressive FPP (SC-FPP), a high-speed 3D imaging method that integrates FPP with snapshot compressive imaging (SCI). By employing random spatial optical field encoding and subsequent fringe images recovery, SC-FPP enables high-resolution 3D imaging at up to Bf/P Hz (B is the compression ratio). Hybrid simulation experiment results show that SC-FPP enables 3D imaging at over 1 kHz using an industrial camera by setting B=P. At the same time, accuracy validation further demonstrates that SC-FPP delivers superior measurement precision, reaching an RMSE of 36.6 μm in standard sphere tests. This method breaks through the hardware frame-rate limit of industrial cameras, providing a low-cost, high-performance solution for in-process high-speed 3D monitoring.