Vendi 异常分数:高效准确的异常检测
Vendi Anomaly Scores for Efficient and Accurate Anomaly Detection
Amey Pasarkar, Adji Bousso Dieng
AI 速读 基于摘要
作者提出从多样性视角定义异常检测的 Vendi 异常分数(VAS),通过移除样本后数据集多样性的变化来识别异常,并在多组基准嵌入数据集与 ImageNet 实验上报告了有竞争力的结果。
cs.LG
查看原文摘要
Anomaly detection (AD) is a critical for trustworthy machine learning and scientific discovery. Existing methods typically define anomalies through local density, isolation heuristics, or distance from a fitted distribution, making them sensitive to neighborhood scale, partitioning choices, or restrictive distributional assumptions. In this work, we introduce a new paradigm by formulating anomaly detection from a diversity perspective. We propose the $\textit{Vendi Anomaly Score}$ (VAS), which detects anomalies by quantifying how much a sample changes the diversity of the dataset, as measured by the Vendi score, when removed. VAS captures both local redundancy and global data structure without relying on density estimation or partitioning heuristics. Moreover, VAS requires no hyperparameter tuning, instead adapting automatically to the spectral structure of the data. VAS is non-parametric and scales linearly with dataset size. Across 148 benchmark embedding datasets derived from 10 source datasets and 4 embedding architectures, VAS achieves state-of-the-art AD performance. We further validate VAS on large-scale ImageNet experiments, where it remains robust as both contamination rate and dataset scale increase.