Few Annotated Pixels and Point Cloud Based Weakly Supervised Semantic Segmentation of Driving Scenes

Previous weakly supervised semantic segmentation (WSSS) methods mainly begin with the segmentation seeds from the CAM method. Because of the high complexity of driving scene images, their framework performs not well on driving scene datasets. In this paper, we propose a new kind of WSSS annotations on the complex driving scene dataset, with only one or several labeled points per category. This annotation is more lightweight than image-level annotation and provides critical localization information for prototypes. We propose a framework to address the WSSS task under this annotation, which generates prototype feature vectors from labeled points and then produces 2D pseudo labels. Besides, we found the point cloud data is useful for distinguishing different objects. Our framework could extract rich semantic information from unlabeled point cloud data and generate instance masks, which does not require extra annotation resources. We combine the pseudo labels and the instance masks to modify the incorrect regions and thus obtain more accurate supervision for training the semantic segmentation network. We evaluated this framework on the KITTI dataset. Experiments show that the proposed method achieves state-of-the-art performance.