SfM-Free 3D Gaussian Splatting via Hierarchical Training
This addresses the need for more efficient and accessible 3D scene reconstruction in computer vision, though it is incremental as it builds on existing 3D Gaussian Splatting techniques.
The paper tackles the problem of 3D Gaussian Splatting requiring known camera poses and SfM preprocessing by proposing an SfM-free method for video input, achieving significant improvements in novel view synthesis, such as an average PSNR gain of 2.25dB on the Tanks and Temples dataset.
Standard 3D Gaussian Splatting (3DGS) relies on known or pre-computed camera poses and a sparse point cloud, obtained from structure-from-motion (SfM) preprocessing, to initialize and grow 3D Gaussians. We propose a novel SfM-Free 3DGS (SFGS) method for video input, eliminating the need for known camera poses and SfM preprocessing. Our approach introduces a hierarchical training strategy that trains and merges multiple 3D Gaussian representations -- each optimized for specific scene regions -- into a single, unified 3DGS model representing the entire scene. To compensate for large camera motions, we leverage video frame interpolation models. Additionally, we incorporate multi-source supervision to reduce overfitting and enhance representation. Experimental results reveal that our approach significantly surpasses state-of-the-art SfM-free novel view synthesis methods. On the Tanks and Temples dataset, we improve PSNR by an average of 2.25dB, with a maximum gain of 3.72dB in the best scene. On the CO3D-V2 dataset, we achieve an average PSNR boost of 1.74dB, with a top gain of 3.90dB. The code is available at https://github.com/jibo27/3DGS_Hierarchical_Training.