Fast Underwater Scene Reconstruction using Multi-View Stereo and Physical Imaging

Underwater scene reconstruction poses a substantial challenge because of the intricate interplay between light and the medium, resulting in scattering and absorption effects that make both depth estimation and rendering more complex. While recent Neural Radiance Fields (NeRF) based methods for underwater scenes achieve high-quality results by modeling and separating the scattering medium, they still suffer from slow training and rendering speeds. To address these limitations, we propose a novel method that integrates Multi-View Stereo (MVS) with a physics-based underwater image formation model. Our approach consists of two branches: one for depth estimation using the traditional cost volume pipeline of MVS, and the other for rendering based on the physics-based image formation model. The depth branch improves scene geometry, while the medium branch determines the scattering parameters to achieve precise scene rendering. Unlike traditional MVSNet methods that rely on ground-truth depth, our method does not necessitate the use of depth truth, thus allowing for expedited training and rendering processes. By leveraging the medium subnet to estimate the medium parameters and combining this with a color MLP for rendering, we restore the true colors of underwater scenes and achieve higher-fidelity geometric representations. Experimental results show that our method enables high-quality synthesis of novel views in scattering media, clear views restoration by removing the medium, and outperforms existing methods in rendering quality and training efficiency.