Cross-modal and Cross-domain Knowledge Transfer for Label-free 3D Segmentation

Current state-of-the-art point cloud-based perception methods usually rely on large-scale labeled data, which requires expensive manual annotations. A natural option is to explore the unsupervised methodology for 3D perception tasks. However, such methods often face substantial performance-drop difficulties. Fortunately, we found that there exist amounts of image-based datasets and an alternative can be proposed, i.e., transferring the knowledge in the 2D images to 3D point clouds. Specifically, we propose a novel approach for the challenging cross-modal and cross-domain adaptation task by fully exploring the relationship between images and point clouds and designing effective feature alignment strategies. Without any 3D labels, our method achieves state-of-the-art performance for 3D point cloud semantic segmentation on SemanticKITTI by using the knowledge of KITTI360 and GTA5, compared to existing unsupervised and weakly-supervised baselines.

One Training for Multiple Deployments: Polar-based Adaptive BEV Perception for Autonomous Driving

Current on-board chips usually have different computing power, which means multiple training processes are needed for adapting the same learning-based algorithm to different chips, costing huge computing resources. The situation becomes even worse for 3D perception methods with large models. Previous vision-centric 3D perception approaches are trained with regular grid-represented feature maps of fixed resolutions, which is not applicable to adapt to other grid scales, limiting wider deployment. In this paper, we leverage the Polar representation when constructing the BEV feature map from images in order to achieve the goal of training once for multiple deployments. Specifically, the feature along rays in Polar space can be easily adaptively sampled and projected to the feature in Cartesian space with arbitrary resolutions. To further improve the adaptation capability, we make multi-scale contextual information interact with each other to enhance the feature representation. Experiments on a large-scale autonomous driving dataset show that our method outperforms others as for the good property of one training for multiple deployments.

Vision-Centric BEV Perception: A Survey

Vision-centric BEV perception has recently received increased attention from both industry and academia due to its inherent merits, including presenting a natural representation of the world and being fusion-friendly. With the rapid development of deep learning, numerous methods have been proposed to address the vision-centric BEV perception. However, there is no recent survey for this novel and growing research field. To stimulate its future research, this paper presents a comprehensive survey of recent progress of vision-centric BEV perception and its extensions. It collects and organizes the recent knowledge, and gives a systematic review and summary of commonly used algorithms. It also provides in-depth analyses and comparative results on several BEV perception tasks, facilitating the comparisons of future works and inspiring future research directions. Moreover, empirical implementation details are also discussed and shown to benefit the development of related algorithms.