DS-MAE: Dual-Siamese masked autoencoders for point cloud analysis

Masked autoencoders (MAEs) have emerged as a powerful self-supervised approach for point cloud analysis. Nevertheless, existing methods often separately focus on global structures or multi-scale features, ignoring their complementary potential. In this paper, we propose a novel dual-Siamese masked autoencoder (DS-MAE) framework that explores integrating global and hierarchical feature learning in a unified architecture for point cloud analysis. In particular, we introduce a consistent dual-branch patch embedding strategy to partition the point cloud into patches using shared group centers, ensuring both global and hierarchical branches process point patches centered at the same spatial locations. Each branch employs dual-branch Siamese encoders to process original and augmented point patches, learning representations that capture both local details and global context. In addition, we have designed cross-attention Siamese decoders to reconstruct masked point patches and align features both within and between branches with crossattention mechanisms. Comprehensive experiments demonstrate our method consistently achieves superior results to prior methods. Code is available at https://github.com/shaoandy1211/DS-MAE.git.