PromptVAD: Abnormal Prompt via Vision-Language Model
- 30 October 2025
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Neural Networks and Learning Systems
- Vol. 37 (3) , 1018-1032
Abstract
Weakly supervised video anomaly detection (WSVAD) aims at predicting frame-level anomaly scores by modeling training videos with video-level annotations. The category names of abnormal events contain high-level knowledge abstracted by humans about abnormalities, which is of great help in identifying abnormal events. To utilize the knowledge implicit in category names, based on the visual-language pretraining model, we introduce a learnable abnormal prompt from three aspects: learnable domain prompt, learnable category prompt, and nonlearnable category definition prompt. Based on the learnable abnormal prompt, we propose a novel fine-grained WSVAD method: PromptVAD, which exploits a learnable abnormal prompt to reduce the semantic gap between visual images and anomaly categories. Through a similarity measure and our proposed coarse-grained two-class prompt module, our PromptVAD jointly learns coarse-grained and fine-grained VAD. Extensive experimental results on the ShanghaiTech, University of Central Florida (UCF)-Crime, and XD-Violence datasets show that our method achieves state-of-the-art performance. Specifically, our method achieves an area under the curve (AUC) of 88.62% on the UCF-Crime dataset.Keywords
Funding Information
- National Natural Science Foundation of China (62406231)
- National Natural Science Foundation of China (62576264)
- Shaanxi Province Post-Doctoral Research Project Funding (2024BSHSDZZ119)
- China Post-Doctoral Science Foundation (2023M742738)
- National Science and Technology Major Project (2025ZD0551500)
- National Science and Technology Major Project (2025ZD0551502)
- Joint Fund Project of National Natural Science Foundation of China (U22B2054)
- Fund for Foreign Scholars in University Research and Teaching Programs (B07048)
- Program for Cheung Kong Scholars and Innovative Research Team in University (IRT_15R53)
- Key Scientific Technological Innovation Research Project by Ministry of Education
- National Key Laboratory of Human–Machine Hybrid Augmented Intelligence, Xi’an Jiaotong University (HMHAI-202404)
- National Key Laboratory of Human–Machine Hybrid Augmented Intelligence, Xi’an Jiaotong University (HMHAI-202405)
This publication has 80 references indexed in Scilit:
- Surgical video workflow analysis via visual-language learningnpj Health Systems, 2025
- Advanced Deep Learning Models for 6G: Overview, Opportunities, and ChallengesIEEE Access, 2024
- Multi-modal visual tracking based on textual generationInformation Fusion, 2024
- MinEnt: Minimum entropy for self-supervised representation learningPattern Recognition, 2023
- Self-supervised Sparse Representation for Video Anomaly Detection2022
- Scale-Aware Spatio-Temporal Relation Learning for Video Anomaly Detection2022
- Learning to Prompt for Vision-Language ModelsInternational Journal of Computer Vision, 2022
- CLAWS: Clustering Assisted Weakly Supervised Learning with Normalcy Suppression for Anomalous Event Detection2020
- Not only Look, But Also Listen: Learning Multimodal Violence Detection Under Weak Supervision2020
- A Survey of Deep Learning-Based Object DetectionIEEE Access, 2019