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Related papers: Constrained unsupervised anomaly segmentation

200 papers

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

Detection of various lesions in brain MRI is clinically critical, but challenging due to the diversity of lesions and variability in imaging conditions. Current unsupervised learning methods detect anomalies mainly through reconstructing…

Computer Vision and Pattern Recognition · Computer Science 2025-12-29 Tao Yang , Xiuying Wang , Hao Liu , Guanzhong Gong , Lian-Ming Wu , Yu-Ping Wang , Lisheng Wang

Contrastive Analysis (CA) detects anomalies by contrasting patterns unique to a target group (e.g., unhealthy subjects) from those in a background group (e.g., healthy subjects). In the context of brain MRIs, existing CA approaches rely on…

Computer Vision and Pattern Recognition · Computer Science 2025-07-02 Cristiano Patrício , Carlo Alberto Barbano , Attilio Fiandrotti , Riccardo Renzulli , Marco Grangetto , Luis F. Teixeira , João C. Neves

Harnessing the power of deep neural networks in the medical imaging domain is challenging due to the difficulties in acquiring large annotated datasets, especially for rare diseases, which involve high costs, time, and effort for…

Image and Video Processing · Electrical Eng. & Systems 2023-08-22 Md Mahfuzur Rahman Siddiquee , Jay Shah , Teresa Wu , Catherine Chong , Todd J. Schwedt , Gina Dumkrieger , Simona Nikolova , Baoxin Li

The goal of unsupervised anomaly segmentation (UAS) is to detect the pixel-level anomalies unseen during training. It is a promising field in the medical imaging community, e.g, we can use the model trained with only healthy data to segment…

Image and Video Processing · Electrical Eng. & Systems 2021-03-17 Chenxin Li , Yunlong Zhang , Jiongcheng Li , Yue Huang , Xinghao Ding

Unsupervised anomaly detection aims to build models to effectively detect unseen anomalies by only training on the normal data. Although previous reconstruction-based methods have made fruitful progress, their generalization ability is…

Machine Learning · Computer Science 2022-01-04 Yuxin Zhang , Jindong Wang , Yiqiang Chen , Han Yu , Tao Qin

Unsupervised anomaly detection methods offer a promising and flexible alternative to supervised approaches, holding the potential to revolutionize medical scan analysis and enhance diagnostic performance. In the current landscape, it is…

Image and Video Processing · Electrical Eng. & Systems 2023-08-29 Cosmin I. Bercea , Esther Puyol-Antón , Benedikt Wiestler , Daniel Rueckert , Julia A. Schnabel , Andrew P. King

Semi-supervised learning relaxes the need of large pixel-wise labeled datasets for image segmentation by leveraging unlabeled data. A prominent way to exploit unlabeled data is to regularize model predictions. Since the predictions of…

Computer Vision and Pattern Recognition · Computer Science 2023-10-26 Sukesh Adiga , Jose Dolz , Herve Lombaert

Unsupervised anomaly segmentation approaches to pathology segmentation train a model on images of healthy subjects, that they define as the 'normal' data distribution. At inference, they aim to segment any pathologies in new images as…

Image and Video Processing · Electrical Eng. & Systems 2024-06-06 Ziyun Liang , Xiaoqing Guo , J. Alison Noble , Konstantinos Kamnitsas

We address the problem of anomaly detection, that is, detecting anomalous events in a video sequence. Anomaly detection methods based on convolutional neural networks (CNNs) typically leverage proxy tasks, such as reconstructing input video…

Computer Vision and Pattern Recognition · Computer Science 2020-03-31 Hyunjong Park , Jongyoun Noh , Bumsub Ham

Unsupervised anomaly detection (UAD) aims to detect anomalies without labeled data, a necessity in many machine learning applications where anomalous samples are rare or not available. Most state-of-the-art methods fall into two categories:…

Machine Learning · Computer Science 2025-07-30 Nicolas Pinon , Carole Lartizien

In this paper we consider the problem of unsupervised anomaly segmentation in medical images, which has attracted increasing attention in recent years due to the expensive pixel-level annotations from experts and the existence of a large…

Image and Video Processing · Electrical Eng. & Systems 2021-12-20 Raunak Dey , Wenbo Sun , Haibo Xu , Yi Hong

Selecting informative data points for expert feedback can significantly improve the performance of anomaly detection (AD) in various contexts, such as medical diagnostics or fraud detection. In this paper, we determine a set of theoretical…

Machine Learning · Computer Science 2023-07-06 Aodong Li , Chen Qiu , Marius Kloft , Padhraic Smyth , Stephan Mandt , Maja Rudolph

We focus on a specific use case in anomaly detection where the distribution of normal samples is supported by a lower-dimensional manifold. Here, regularized autoencoders provide a popular approach by learning the identity mapping on the…

Computer Vision and Pattern Recognition · Computer Science 2024-05-14 Alexander Bauer , Shinichi Nakajima , Klaus-Robert Müller

This work presents a novel deep learning framework for segmenting cerebral vasculature in hyperspectral brain images. We address the critical challenge of severe label scarcity, which impedes conventional supervised training. Our approach…

Computer Vision and Pattern Recognition · Computer Science 2025-08-26 Tim Mach , Daniel Rueckert , Alex Berger , Laurin Lux , Ivan Ezhov

The essence of unsupervised anomaly detection is to learn the compact distribution of normal samples and detect outliers as anomalies in testing. Meanwhile, the anomalies in real-world are usually subtle and fine-grained in a…

Computer Vision and Pattern Recognition · Computer Science 2022-07-20 Ye Zheng , Xiang Wang , Rui Deng , Tianpeng Bao , Rui Zhao , Liwei Wu

Surrogate task based methods have recently shown great promise for unsupervised image anomaly detection. However, there is no guarantee that the surrogate tasks share the consistent optimization direction with anomaly detection. In this…

Computer Vision and Pattern Recognition · Computer Science 2020-12-10 Fei Ye , Huangjie Zheng , Chaoqin Huang , Ya Zhang

Anomaly detection (AD) is the identification of data samples that do not fit a learned data distribution. As such, AD systems can help physicians to determine the presence, severity, and extension of a pathology. Deep generative models,…

Image and Video Processing · Electrical Eng. & Systems 2021-04-12 Jaime Simarro , Ezequiel de la Rosa , Thijs Vande Vyvere , David Robben , Diana M. Sima

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

Anomaly detection in MRI is of high clinical value in imaging and diagnosis. Unsupervised methods for anomaly detection provide interesting formulations based on reconstruction or latent embedding, offering a way to observe properties…

Image and Video Processing · Electrical Eng. & Systems 2022-11-29 Ayantika Das , Arun Palla , Keerthi Ram , Mohanasankar Sivaprakasam