将有监督单类分类器转为无监督异常检测新方法,无需修改原模型。
BAAF: Universal Transformation of One-Class Classifiers for Unsupervised Image Anomaly Detection
- 利用异常稀少且异质的特性,通过改进自助采样过滤训练数据
- 在MVTec AD等3个数据集上达到顶尖无监督检测性能
- 适用于任何单类分类器,可自动升级现有模型
图像与视频中的异常检测对工业质检、医疗辅助诊断和环境监测等任务至关重要。异常检测通常被建模为单类分类问题,训练数据仅包含正常样本,导致基于此假设的方法易受标签噪声影响。本文提出Bootstrap Aggregation Anomaly Filtering(BAAF),将任意基于单类分类器的异常检测器转化为完全无监督方法。该方法利用异常在采样数据中稀少且异质的内在特性,设计了一种改进的自助采样机制,通过多个独立训练的监督单类分类器对训练数据进行异常过滤。该转换无需修改底层检测器,仅改变用于训练的数据包。实验表明,该方法可将多种单类分类器驱动的图像异常检测器转变为无监督版本,首次实现图像领域的无监督逻辑异常检测。同时,在MVTec AD、ViSA和MVTec Loco AD数据集上达到当前最优无监督检测性能。随着单类分类器的改进,本方法能直接将其优势迁移至无监督领域,实现两者的有效衔接。
原文摘要 · Abstract (English)
Detecting anomalies in images and video is an essential task for multiple real-world problems, including industrial inspection, computer-assisted diagnosis, and environmental monitoring. Anomaly detection is typically formulated as a one-class classification problem, where the training data consists solely of nominal values, leaving methods built on this assumption susceptible to training label noise. We present Bootstrap Aggregation Anomaly Filtering (BAAF), a method that transforms an arbitrary one-class classifier-based anomaly detector into a fully unsupervised method. This is achieved by leveraging the unique intrinsic properties of anomaly detection: anomalies are uncommon in the sampled data and generally heterogeneous. These properties enable us to design a modified Bootstrap Aggregation method that uses multiple independently trained instances of supervised one-class classifiers to filter the training dataset for anomalies. This transformation requires no modifications to the underlying anomaly detector; only the algorithmically selected data bags used for training change. We demonstrate empirically that our method can transform a wide variety of one-class classifier-based image anomaly detectors into unsupervised ones. Consequently, we present the first unsupervised logical anomaly detectors for images. We also demonstrate that our method achieves state-of-the-art performance in fully unsupervised anomaly detection on the MVTec AD, ViSA, and MVTec Loco AD datasets. As improvements to one-class classifiers are made, our method directly transfers those improvements to the unsupervised domain, linking the domains.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。