Aggregation and Purification: Dual Enhancement Network for Point Cloud Few-shot Segmentation

Abstract

Point cloud few-shot semantic segmentation (PC-FSS) aims to segment objects within query samples of new categories given only a handful of annotated support samples. Although PC-FSS demonstrates enhanced category generalization capabilities compared to the fully supervised paradigm, the prevalent significant scene discrepancies, which can be systematically summarized into intra-semantic diversity and semantic inconsistency, have posed substantial challenges to the area. In this work, we design a novel Dual Enhancement Network (DENet) to comprehensively tackle different kinds of scene discrepancies in a coherent and synergistic framework. The proposed DENet enjoys several merits. First, we design a mutual aggregation module to reconcile the intrinsic tension between the support prototypes and query point features, and the intra-semantic diversity is diminished in a bidirectional manner. Second, the consistent purification strategy is introduced to eliminate ambiguous prototypes, thereby reducing the mismatches brought by semantic inconsistency. Extensive experiments on S3DIS and ScanNet under different settings demonstrate that DENet significantly outperforms previous SOTAs.