Point2Vec for Self-Supervised Representation Learning on Point Clouds

29 Mar 2023  ·  Karim Abou Zeid, Jonas Schult, Alexander Hermans, Bastian Leibe ·

Recently, the self-supervised learning framework data2vec has shown inspiring performance for various modalities using a masked student-teacher approach. However, it remains open whether such a framework generalizes to the unique challenges of 3D point clouds. To answer this question, we extend data2vec to the point cloud domain and report encouraging results on several downstream tasks. In an in-depth analysis, we discover that the leakage of positional information reveals the overall object shape to the student even under heavy masking and thus hampers data2vec to learn strong representations for point clouds. We address this 3D-specific shortcoming by proposing point2vec, which unleashes the full potential of data2vec-like pre-training on point clouds. Our experiments show that point2vec outperforms other self-supervised methods on shape classification and few-shot learning on ModelNet40 and ScanObjectNN, while achieving competitive results on part segmentation on ShapeNetParts. These results suggest that the learned representations are strong and transferable, highlighting point2vec as a promising direction for self-supervised learning of point cloud representations.

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Results from the Paper


Task Dataset Model Metric Name Metric Value Global Rank Uses Extra
Training Data
Benchmark
3D Point Cloud Classification ModelNet40 point2vec Overall Accuracy 94.8 # 5
Mean Accuracy 92.0 # 5
Few-Shot 3D Point Cloud Classification ModelNet40 10-way (10-shot) point2vec Overall Accuracy 93.9 # 4
Standard Deviation 4.1 # 13
Few-Shot 3D Point Cloud Classification ModelNet40 10-way (20-shot) point2vec Overall Accuracy 95.8 # 3
Standard Deviation 3.1 # 16
Few-Shot 3D Point Cloud Classification ModelNet40 5-way (10-shot) point2vec Overall Accuracy 97.0 # 7
Standard Deviation 2.8 # 15
Few-Shot 3D Point Cloud Classification ModelNet40 5-way (20-shot) point2vec Overall Accuracy 98.7 # 4
Standard Deviation 1.2 # 4
3D Point Cloud Classification ScanObjectNN point2vec Overall Accuracy 87.5 # 29
Mean Accuracy 86.0 # 14
OBJ-BG (OA) 91.2 # 12
OBJ-ONLY (OA) 90.4 # 10
3D Part Segmentation ShapeNet-Part point2vec Class Average IoU 84.6 # 11
Instance Average IoU 86.3 # 27

Methods