Revisiting the Learning Stage in Range View Representation for Autonomous Driving

LiDAR segmentation is crucial for autonomous driving perception. Range view methods have been widely adopted for these applications due to their intuitiveness and ease of implementation. However, the inherent shortcomings of the range view approach (e.g., assuming that point clouds within the same pixel of a range image have the same semantic class) make it difficult to perform accurate fine-grained segmentation tasks, thus limiting its potential in practical applications. To address these issues, we propose RangeFusion, an end-to-end framework that greatly improves the ability to learn and process LiDAR point clouds from range views by employing a multispatial learning model. A novel range-scan space (RSS) is proposed to address the inability of existing range view methods to accurately aggregate features of neighboring points. This space achieves accurate and efficient neighboring point feature aggregation with linear time complexity. In addition, a supervised label smoothing method called multilevel feature selection heads (MFSHs) is designed, which achieves more fine-grained semantic prediction by subdividing the full point cloud into multisemantic hierarchical subclouds and adaptively fusing the features with confidence filtering. The performance of the proposed method was evaluated on several benchmarks, including SemanticKITTI and nuScenes. On these two datasets, mean intersection over union (mIoU) scores of 67.9% and 80.2% were achieved, respectively. This demonstrates that the proposed approach outperforms existing range view- and multiview-based approaches while maintaining efficient performance at 26.5 FPS. In addition, real road data were collected for testing. The code is available at https://github.com/Wansit99/RangeFusion.