Two-layer 3D imaging through semi-transparent surface based on FPP-constrained parallel single-pixel detection

Three-dimensional (3D) imaging through a semi-transparent surface is challenging for traditional structured light techniques due to its point-to-point triangulation, which must follow single reflection conditions. Emerging parallel single-pixel imaging technique offers a promising alternative but is bottlenecked by low measurement efficiency due to its spectrum scanning characteristics. In addition, the limited measurement depth is also a drawback. To address this, a fringe projection profilometry (FPP)-constrained parallel single-pixel detection method was proposed. Firstly, the vector superposition property of FPP is introduced to demonstrate the interlayer-constrained effect of the two-layer superimposed phase. Then, the FPP-constrained localization method is proposed based on interlayer constrained effect, providing a flexible and adaptive depth constraint range. Experimental results demonstrate the proposed method can achieve dynamic two-layer 3D imaging through a semi-transparent surface in an unconstrained depth range. The proposed method points a way forward for efficient and accurate 3D imaging of multi-depth scenarios.