Exploring Few-Beam LiDAR Assistance in Self-Supervised Multi-Frame Depth Estimation

Self-supervised multi-frame depth estimation methods only require unlabeled monocular videos for training. However, most existing methods face challenges, including accuracy degradation caused by moving objects in dynamic scenes and scale ambiguity due to the absence of real-world references. In this field, the emergence of low-cost LiDAR sensors highlights the potential to improve the robustness of multi-frame depth estimation by exploiting accurate sparse measurements at the correct scale. Moreover, the LiDAR ranging points often intersect moving objects, providing more precise depth cues for them. This paper explores the impact of few-beam LiDAR data on self-supervised multi-frame depth estimation, proposing a method that fuses multi-frame matching and sparse depth features. It significantly enhances depth estimation robustness, particularly in scenarios involving moving objects and textureless backgrounds. We demonstrate the effectiveness of our approach through comprehensive experiments, showcasing its potential to address the limitations of existing methods and paving the way for more robust and reliable depth estimation based on this paradigm.