Papers › Attack-Augmentation Mixing-Contrastive Skeletal Representation Learning

Attack-Augmentation Mixing-Contrastive Skeletal Representation Learning

8 Apr 2023arXiv:2304.04023archive 2025-07-28

Binqian Xu, Xiangbo Shu, Jiachao Zhang, Rui Yan, Guo-Sen Xie

Contrastive learning, relying on effective positive and negative sample pairs, is beneficial to learn informative skeleton representations in unsupervised skeleton-based action recognition. To achieve these positive and negative pairs, existing weak/strong data augmentation methods have to randomly change the appearance of skeletons for indirectly pursuing semantic perturbations. However, such approaches have two limitations: i) solely perturbing appearance cannot well capture the intrinsic semantic information of skeletons, and ii) randomly perturbation may change the original positive/negative pairs to soft positive/negative ones. To address the above dilemma, we start the first attempt to explore an attack-based augmentation scheme that additionally brings in direct semantic perturbation, for constructing hard positive pairs and further assisting in constructing hard negative pairs. In particular, we propose a novel Attack-Augmentation Mixing-Contrastive skeletal representation learning (A²MC) to contrast hard positive features and hard negative features for learning more robust skeleton representations. In A²MC, Attack-Augmentation (Att-Aug) is designed to collaboratively perform targeted and untargeted perturbations of skeletons via attack and augmentation respectively, for generating high-quality hard positive features. Meanwhile, Positive-Negative Mixer (PNM) is presented to mix hard positive features and negative features for generating hard negative features, which are adopted for updating the mixed memory banks. Extensive experiments on three public datasets demonstrate that A²MC is competitive with the state-of-the-art methods. The code will be accessible on A²MC (https://github.com/1xbq1/A2MC).

PaperPDFCode

Code

1xbq1/a2mc officialmentioned in paperpytorch report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

Not run by Syntology. Nothing on this page verifies that the listed code works.

Tasks

Action RecognitionContrastive LearningData AugmentationRepresentation LearningSkeleton Based Action RecognitionUnsupervised Skeleton Based Action Recognition

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections