Towards Visibility Estimation and Noise-Distribution-Based Defogging for LiDAR in Autonomous Driving

Point clouds play a crucial role in robots and intelligent vehicles. Noise caused by fog droplets seriously degrades the quality of point clouds. Previous researches have shown that the extent of degradation is correlated with visibility. The fog attenuation coefficient is associated with visibility. In light of this background, this paper proposes a noise-distribution-based defogging method for point clouds. Our approach hinges on the estimation of the fog attenuation coefficient, facilitated by road-based prior knowledge. Subsequently, our method integrates the fog-induced noise distribution inferred from the LiDAR imaging model with the spatially non-uniform distribution of point clouds caused by LiDAR structure. The fused results are input to a statistical filter based on the relative sparsity of noise to achieve defogging. This paper is one of the early works focusing on point cloud defogging. Its core insight lies in the estimation of the attenuation coefficient and the employment of fog-induced noise distribution for defogging. Experiments demonstrate that our method can accurately mitigate the impact of fog and meanwhile enhance the performance of 3D object detection network.