PoI: A Filter to Extract Pixel of Interest from Novel View Synthesis for Scene Coordinate Regression (2502.04843v3)

Abstract: Novel View Synthesis (NVS) techniques, notably Neural Radiance Fields (NeRF) and 3D Gaussian Splatting (3DGS), can augment camera pose estimation by extending and diversifying training data. However, images generated by these methods are often plagued by spatial artifacts such as blurring and ghosting, undermining their reliability as training data for camera pose estimation. This limitation is particularly critical for Scene Coordinate Regression (SCR) methods, which aim at pixel-level 3D coordinate estimation, because rendering artifacts directly lead to estimation inaccuracies. To address this challenge, we propose a dual-criteria filtering mechanism that dynamically identifies and discards suboptimal pixels during training. The dual-criteria filter evaluates two concurrent metrics: (1) real-time SCR reprojection error, and (2) gradient threshold, across the coordinate regression domain. In addition, for visual localization problems in sparse-input scenarios, it becomes even more necessary to use NVS-generated data to assist localization. We design a coarse-to-fine Points of Interest (PoI) variant using sparse-input NVS to solve this problem. Experiments across indoor and outdoor benchmarks confirm our method's efficacy, achieving state-of-the-art localization accuracy while maintaining computational efficiency.