Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Kamide, Koichiro, Sakai, Shunsuke, Maeda, Shun, Gu, Chunzhi, Zhang, Chao
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:https://arxiv.org/abs/2508.17726
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866914002801524736
author Kamide, Koichiro
Sakai, Shunsuke
Maeda, Shun
Gu, Chunzhi
Zhang, Chao
author_facet Kamide, Koichiro
Sakai, Shunsuke
Maeda, Shun
Gu, Chunzhi
Zhang, Chao
contents Human Action Anomaly Detection (HAAD) aims to identify anomalous actions given only normal action data during training. Existing methods typically follow a one-model-per-category paradigm, requiring separate training for each action category and a large number of normal samples. These constraints hinder scalability and limit applicability in real-world scenarios, where data is often scarce or novel categories frequently appear. To address these limitations, we propose a unified framework for HAAD that is compatible with few-shot scenarios. Our method constructs a category-agnostic representation space via contrastive learning, enabling AD by comparing test samples with a given small set of normal examples (referred to as the support set). To improve inter-category generalization and intra-category robustness, we introduce a generative motion augmentation strategy harnessing a diffusion-based foundation model for creating diverse and realistic training samples. Notably, to the best of our knowledge, our work is the first to introduce such a strategy specifically tailored to enhance contrastive learning for action AD. Extensive experiments on the HumanAct12 dataset demonstrate the state-of-the-art effectiveness of our approach under both seen and unseen category settings, regarding training efficiency and model scalability for few-shot HAAD.
format Preprint
id arxiv_https___arxiv_org_abs_2508_17726
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Few-shot Human Action Anomaly Detection via a Unified Contrastive Learning Framework
Kamide, Koichiro
Sakai, Shunsuke
Maeda, Shun
Gu, Chunzhi
Zhang, Chao
Computer Vision and Pattern Recognition
Human Action Anomaly Detection (HAAD) aims to identify anomalous actions given only normal action data during training. Existing methods typically follow a one-model-per-category paradigm, requiring separate training for each action category and a large number of normal samples. These constraints hinder scalability and limit applicability in real-world scenarios, where data is often scarce or novel categories frequently appear. To address these limitations, we propose a unified framework for HAAD that is compatible with few-shot scenarios. Our method constructs a category-agnostic representation space via contrastive learning, enabling AD by comparing test samples with a given small set of normal examples (referred to as the support set). To improve inter-category generalization and intra-category robustness, we introduce a generative motion augmentation strategy harnessing a diffusion-based foundation model for creating diverse and realistic training samples. Notably, to the best of our knowledge, our work is the first to introduce such a strategy specifically tailored to enhance contrastive learning for action AD. Extensive experiments on the HumanAct12 dataset demonstrate the state-of-the-art effectiveness of our approach under both seen and unseen category settings, regarding training efficiency and model scalability for few-shot HAAD.
title Few-shot Human Action Anomaly Detection via a Unified Contrastive Learning Framework
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2508.17726