CORTEXA
← Browse
arxivcs.CV2026-06-28

Learning Where and When: Patch-Based Spatiotemporal Localization in Weakly Supervised Video Anomaly Detection

Hamza Karim, Nghia Nguyen, Lokman Bekit, Yasin Yilmaz

Weakly supervised video anomaly detection (WSVAD) has predominantly focused on temporal localization, identifying when anomalies occur while largely neglecting their spatial extent within frames. Yet, spatial localization is essential for interpretability and practical deployment in real-world settings. We introduce a patch-based spatiotemporal framework for weakly supervised anomaly localization that jointly models where and when anomalies occur. Our approach operates on grid-level patch features and learns region-level anomaly scores under a multiple instance learning paradigm. We further propose a Proximity-Aware Top-k spatiotemporal selection strategy that enables the model to generate fine-grained spatial anomaly maps without requiring bounding-box supervision during training. Our method surpasses existing state-of-the-art approaches across multiple benchmarks, yielding substantial gains in spatiotemporal localization accuracy. In addition, we release frame-level bounding-box annotations for the test sets of two widely used datasets, along with our code and pretrained models, providing new resources to facilitate future research in spatially grounded WSVAD.

View free PDFSource page

Related papers

arxivcs.CV2026-07-03

CL-Anomaly: Layer-Adaptive Mixture-of-Experts with Multimodal Large Language Model for Continual Learning in Anomaly Detection

Wen Dong, Zhao Wang, Shuangqing Zhang, Kai Sun, Ben Li, Guo-Sen Xie, et al.

Multimodal Large Language Models (MLLMs) excel in diverse vision tasks, but full-parameter retraining is computationally expensive as real-world knowledge evolves. Existing continual learning methods often suffer from semantic entanglement in parameter spaces across tasks, impedi…

View free PDFSource page
arxivcs.CV2026-07-11

Structured Evidence Selection for Weakly Supervised Video Anomaly Detection

Chenglizhao Chen, Tianxiang Nan, Wen Li, Xinyu Liu, Guisheng Zhang, Mengke Song, et al.

Weakly supervised video anomaly detection relies solely on video-level labels for training, making it difficult to accurately localize anomalous events in complex scenes. In real-world videos, anomalous behaviors exhibit large variations in appearance and temporal duration, while…

View free PDFSource page
arxivcs.CVcs.AIcs.MM2026-07-10

Event Stream based Multi-Modal Video Anomaly Detection: A Benchmark Dataset and Algorithms

Peipei Zhu, Yueqing Niu, Lin Zhu, Guanchong Niu, Yang Yu, Zheng Li

Video anomaly detection (VAD) is critical for automated surveillance but remains fragile under challenging conditions such as illumination variations, fast motion, and complex backgrounds when relying solely on visible light videos. To address these limitations, we propose EVAD,…

View free PDFSource page
arxivcs.CVcs.LG2026-07-14

Active Learning for Efficient Annotation of Surgical Videos with Weak Supervision

Manasa Dendukuri, Matjaz Jogan, Daniel A. Hashimoto, Guiqiu Liao

Precise spatial-temporal annotation of laparoscopic videos is time-consuming and requires expert knowledge. We propose a human-in-the-loop knowledge acquisition framework that combines active learning with dual-loss optimization to significantly reduce the annotation effort neede…

View free PDFSource page
arxivcs.CVcs.AIcs.CLcs.MA2026-07-20

O-VAD: Industrial Video Anomaly Detection through Object-Centric Tracking and Reasoning

Mei Yuan, Qi Long, Qifeng Wu, Zhenyang Li, Yizhou Zhao, Lei Wang, et al.

Industrial Video Anomaly Detection (IVAD) aims to identify anomalous objects and events in an industrial process, which is crucial for modern manufacturing and quality control systems. Existing VLM-based anomaly reasoning methods are capable of detecting open-ended anomalies in g…

View free PDFSource page
arxivcs.CV2026-07-02

ArcAD: Anomaly-Rectified Calibration for Cold-Start Supervised Anomaly Detection

Ningning Han, Lei Fan, Jia Guo, Yunkang Cao, Xiu Su, Feng Cao, et al.

The deployment of Industrial Anomaly Detection (IAD) in real-world manufacturing frequently encounters a challenging cold-start bottleneck, in which limited normal samples fail to represent the full normal distribution and only a few anomalies are available. Under such a regime,…

View free PDFSource page