水下三维重建的图像空间折射校正：将平端口视图扭曲为针孔透视
Image-Space Refraction Correction for Underwater 3D Reconstruction: Warping Flat-Port Views into Pinhole Perspective
AI总结：
提出基于物理的图像空间折射校正方法，消除平端口水下成像的碗状变形，兼容现有重建与SLAM算法，在真实数据集上提升帧注册并保持低重投影误差。
AI中文摘要：
消费级相机配备平端口外壳，因其低成本和高可达性，被广泛用于珊瑚礁和海底栖息地的水下探索与测绘。然而，平端口界面的折射会导致重建场景和相机轨迹出现碗状变形，损害测绘和导航所需的度量精度。为在重建前消除主要折射畸变，我们提出一种基于物理的图像空间折射校正方法。该方法与下游任务无关：折射校正后的图像可直接用作现有重建和SLAM算法的输入。我们通过光线追踪模拟表征折射畸变，并在两个场景结构不同的真实水下数据集上验证了校正效果。与常规和折射感知的运动恢复结构（SfM）相比，我们的方法在消除重建变形的同时，注册了更多帧并保持较低的重投影误差。该校正还能推广到多种重建和VSLAM后端，展示了其对下游视觉管线的广泛适用性。
英文摘要：
Consumer-grade cameras in flat-port housings are widely used for underwater exploration and mapping of coral reefs and seafloor habitats due to their low cost and accessibility. However, refraction at flat-port interfaces causes bowl-shaped deformation in reconstructed scenes and camera trajectories, compromising the metric accuracy required for mapping and navigation. To remove the dominant refractive distortion before reconstruction, we introduce a physics-based refraction correction in image space. Our method is downstream-agnostic: the refraction-corrected images can be directly used as input to existing reconstruction and SLAM algorithms. We characterize the refractive distortion through ray-tracing simulations and validate our correction on two real underwater datasets with differing scene structures. Compared with conventional and refractive Structure-from-Motion (SfM), our approach removes reconstruction deformation while registering more frames and maintaining low reprojection error. The correction further generalizes across diverse reconstruction and VSLAM backends, demonstrating its broad applicability to downstream vision pipelines.
