Clustering and Unsupervised Anomaly Detection with l2 Normalized Deep Auto-Encoder Representations
Abstract
Clustering is essential to many tasks in pattern recognition and computer vision. With the advent of deep learning, there is an increasing interest in learning deep unsupervised representations for clustering analysis. Many works on this domain rely on variants of auto-encoders and use the encoder outputs as representations/features for clustering. In this paper, we show that an l2normalization constraint on these representations during auto-encoder training, makes the representations more separable and compact in the Euclidean space after training. This greatly improves the clustering accuracy when k-means clustering is employed on the representations. We also propose a clustering based unsupervised anomaly detection method using l2normalized deep auto-encoder representations. We show the effect of l2normalization on anomaly detection accuracy. We further show that the proposed anomaly detection method greatly improves accuracy compared to previously proposed deep methods such as reconstruction error based anomaly detection.
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VT-ADL: A Vision Transformer Network for Image Anomaly Detection and Localization
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“Some of the works handled these two steps independently [25], [26], while others achieved better results by doing the two steps collectively, in order to extract the best features for subsequent anomaly detection [27], [28].”
- Authors
- Aytekin, C., Ni, X., Cricri, F., & Aksu, E.
- Affiliations
- Nokia (Finland) (FI)
- Venue
- 2018 International Joint Conference on Neural Networks (IJCNN)
- Publisher
- IEEE
- Published
- 2018-07
- Pages
- 1-6
- ISSN
- 2161-4407 (ISSN-L)
- OpenAlex
- W2962849408
- Cited by
- 107
- References
- 13
- Citations by year
- 2026: 7 · 2025: 7 · 2024: 9 · 2023: 9 · 2022: 19 · 2021: 17 · 2020: 16 · 2019: 17 · 2018: 6
- FWCI
- 5.69
- Type
- conference paper
- Language
- en
- Open access
- closed
- Locations
- International Joint Conference on Neural Networks (IJCNN) (publishedVersion)
- Topics
- Physical Sciences › Computer Science › Artificial Intelligence › Advanced Clustering Algorithms Research
- Physical Sciences › Computer Science › Artificial Intelligence › Anomaly Detection Techniques and Applications
- Physical Sciences › Computer Science › Computer Vision and Pattern Recognition › Face and Expression Recognition
- Keywords
- deep autoencoder, L2 normalization, unsupervised clustering, unsupervised anomaly detection, K-means clustering, reconstruction error
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