Structured light-based underwater 3-D reconstruction techniques: A comparative study

This paper analyzes the influence of underwater scattering on structured light-based 3-D reconstruction techniques and improves the performance of the 3-D reconstruction under turbid water condition. Two typical structured light-based 3-D reconstruction techniques, fringe projection profilometry (FPP) and single-pixel imaging-based metrology (SIM), are selected to reconstruct the 3-D shape of underwater objects. First, we formulate the error model of underwater FPP, and introduce a Hilbert transform-based method (HT-based FPP) to compensate the measurement error. Second, we first introduce SIM for the underwater 3-D reconstruction, analyze the SNR of underwater image reconstructed by single-pixel imaging, and propose a HSI-based visible region location method to reduce the measurement time. The provided simulation and experiment verify the correctness of the theoretical analysis and the effectiveness of the proposed methods, and compare FPP, HT-based FPP and SIM under water with different turbidities.