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Related papers: Unsupervised Two-Stage Anomaly Detection

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Most advanced unsupervised anomaly detection (UAD) methods rely on modeling feature representations of frozen encoder networks pre-trained on large-scale datasets, e.g. ImageNet. However, the features extracted from the encoders that are…

Computer Vision and Pattern Recognition · Computer Science 2023-10-25 Jia Guo , Shuai Lu , Lize Jia , Weihang Zhang , Huiqi Li

Unsupervised anomaly detection (UAD) aims to find anomalous images by optimising a detector using a training set that contains only normal images. UAD approaches can be based on reconstruction methods, self-supervised approaches, and…

Image and Video Processing · Electrical Eng. & Systems 2023-08-23 Yu Tian , Guansong Pang , Yuyuan Liu , Chong Wang , Yuanhong Chen , Fengbei Liu , Rajvinder Singh , Johan W Verjans , Mengyu Wang , Gustavo Carneiro

In the realm of machine learning, the study of anomaly detection and localization within image data has gained substantial traction, particularly for practical applications such as industrial defect detection. While the majority of existing…

Computer Vision and Pattern Recognition · Computer Science 2023-05-02 Wenping Jin , Fei Guo , Li Zhu

One pivot challenge for image anomaly (AD) detection is to learn discriminative information only from normal class training images. Most image reconstruction based AD methods rely on the discriminative capability of reconstruction error.…

Computer Vision and Pattern Recognition · Computer Science 2020-07-21 Dongyun Lin , Yiqun Li , Shudong Xie , Tin Lay Nwe , Sheng Dong

Unsupervised anomaly detection plays a pivotal role in industrial defect inspection and medical image analysis, with most methods relying on the reconstruction framework. However, these methods may suffer from over-generalization, enabling…

Computer Vision and Pattern Recognition · Computer Science 2026-03-25 Wei Luo , Peng Xing , Yunkang Cao , Haiming Yao , Weiming Shen , Zechao Li

In this paper, we introduce a novel task termed unified anomaly detection and classification, which aims to simultaneously detect anomalous regions in images and identify their specific categories. Existing methods typically treat anomaly…

Computer Vision and Pattern Recognition · Computer Science 2026-02-04 Ximiao Zhang , Min Xu , Zheng Zhang , Junlin Hu , Xiuzhuang Zhou

Current unsupervised anomaly detection approaches perform well on public datasets but struggle with specific anomaly types due to the domain gap between pre-trained feature extractors and target-specific domains. To tackle this issue, this…

Computer Vision and Pattern Recognition · Computer Science 2024-07-02 Yun Liang , Zhiguang Hu , Junjie Huang , Donglin Di , Anyang Su , Lei Fan

Graph anomaly detection (GAD) is a critical task in graph machine learning, with the primary objective of identifying anomalous nodes that deviate significantly from the majority. This task is widely applied in various real-world scenarios,…

Machine Learning · Computer Science 2025-07-03 Xiang Li , Jianpeng Qi , Zhongying Zhao , Guanjie Zheng , Lei Cao , Junyu Dong , Yanwei Yu

We introduce a data-driven anomaly detection framework using a manufacturing dataset collected from a factory assembly line. Given heterogeneous time series data consisting of operation cycle signals and sensor signals, we aim at…

Artificial Intelligence · Computer Science 2022-02-11 Kyeong-Joong Jeong , Jin-Duk Park , Kyusoon Hwang , Seong-Lyun Kim , Won-Yong Shin

Dealing with atypical traffic scenarios remains a challenging task in autonomous driving. However, most anomaly detection approaches cannot be trained on raw sensor data but require exposure to outlier data and powerful semantic…

Computer Vision and Pattern Recognition · Computer Science 2024-10-02 Daniel Bogdoll , Noël Ollick , Tim Joseph , Svetlana Pavlitska , J. Marius Zöllner

Synthetic data provides a promising approach to address data scarcity for training machine learning models; however, adoption without proper quality assessments may introduce artifacts, distortions, and unrealistic features that compromise…

Computer Vision and Pattern Recognition · Computer Science 2025-11-10 Rucha Deshpande , Tahsin Rahman , Miguel Lago , Adarsh Subbaswamy , Jana G. Delfino , Ghada Zamzmi , Elim Thompson , Aldo Badano , Seyed Kahaki

T2 hyperintensities in spinal cord MR images are crucial biomarkers for conditions such as degenerative cervical myelopathy. However, current clinical diagnoses primarily rely on manual evaluation. Deep learning methods have shown promise…

Image and Video Processing · Electrical Eng. & Systems 2025-03-18 Qi Zhang , Xiuyuan Chen , Ziyi He , Kun Wang , Lianming Wu , Hongxing Shen , Jianqi Sun

Recent studies highlighted a practical setting of unsupervised anomaly detection (UAD) that builds a unified model for multi-class images. Despite various advancements addressing this challenging task, the detection performance under the…

Computer Vision and Pattern Recognition · Computer Science 2025-04-03 Jia Guo , Shuai Lu , Weihang Zhang , Fang Chen , Huiqi Li , Hongen Liao

In this work we propose a one-class self-supervised method for anomaly segmentation in images that benefits both from a modern machine learning approach and a more classic statistical detection theory. The method consists of four phases.…

Computer Vision and Pattern Recognition · Computer Science 2024-06-04 Matías Tailanian , Álvaro Pardo , Pablo Musé

The goal of anomaly detection is to identify examples that deviate from normal or expected behavior. We tackle this problem for images. We consider a two-phase approach. First, using normal examples, a convolutional autoencoder (CAE) is…

Computer Vision and Pattern Recognition · Computer Science 2020-03-20 Natasa Sarafijanovic-Djukic , Jesse Davis

Unsupervised image Anomaly Detection (UAD) aims to learn robust and discriminative representations of normal samples. While separate solutions per class endow expensive computation and limited generalizability, this paper focuses on…

Computer Vision and Pattern Recognition · Computer Science 2023-10-24 Ruiying Lu , YuJie Wu , Long Tian , Dongsheng Wang , Bo Chen , Xiyang Liu , Ruimin Hu

Graph anomaly detection is crucial for identifying nodes that deviate from regular behavior within graphs, benefiting various domains such as fraud detection and social network. Although existing reconstruction-based methods have achieved…

Machine Learning · Computer Science 2023-12-25 Junwei He , Qianqian Xu , Yangbangyan Jiang , Zitai Wang , Qingming Huang

Anomaly detection is a task that recognizes whether an input sample is included in the distribution of a target normal class or an anomaly class. Conventional generative adversarial network (GAN)-based methods utilize an entire image…

Computer Vision and Pattern Recognition · Computer Science 2021-04-01 Jou Won Song , Kyeongbo Kong , Ye In Park , Suk-Ju Kang

Unsupervised anomaly detection (UAD) has evolved from building specialized single-class models to unified multi-class models, yet existing multi-class models significantly underperform the most advanced one-for-one counterparts. Moreover,…

Computer Vision and Pattern Recognition · Computer Science 2025-10-27 Jia Guo , Shuai Lu , Lei Fan , Zelin Li , Donglin Di , Yang Song , Weihang Zhang , Wenbing Zhu , Hong Yan , Fang Chen , Huiqi Li , Hongen Liao

Anomaly detection is facing with emerging challenges in many important industry domains, such as cyber security and online recommendation and advertising. The recent trend in these areas calls for anomaly detection on time-evolving data…

Machine Learning · Computer Science 2019-07-16 Zheng Gao , Lin Guo , Chi Ma , Xiao Ma , Kai Sun , Hang Xiang , Xiaoqiang Zhu , Hongsong Li , Xiaozhong Liu
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