Preference Isolation Forest for Structure-based Anomaly Detection

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Leveni, Filippo, Magri, Luca, Alippi, Cesare, Boracchi, Giacomo
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911160239915008
author Leveni, Filippo
Magri, Luca
Alippi, Cesare
Boracchi, Giacomo
author_facet Leveni, Filippo
Magri, Luca
Alippi, Cesare
Boracchi, Giacomo
contents We address the problem of detecting anomalies as samples that do not conform to structured patterns represented by low-dimensional manifolds. To this end, we conceive a general anomaly detection framework called Preference Isolation Forest (PIF), that combines the benefits of adaptive isolation-based methods with the flexibility of preference embedding. The key intuition is to embed the data into a high-dimensional preference space by fitting low-dimensional manifolds, and to identify anomalies as isolated points. We propose three isolation approaches to identify anomalies: $i$) Voronoi-iForest, the most general solution, $ii$) RuzHash-iForest, that avoids explicit computation of distances via Local Sensitive Hashing, and $iii$) Sliding-PIF, that leverages a locality prior to improve efficiency and effectiveness.
format Preprint
id arxiv_https___arxiv_org_abs_2505_10876
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Preference Isolation Forest for Structure-based Anomaly Detection
Leveni, Filippo
Magri, Luca
Alippi, Cesare
Boracchi, Giacomo
Machine Learning
Artificial Intelligence
Computer Vision and Pattern Recognition
We address the problem of detecting anomalies as samples that do not conform to structured patterns represented by low-dimensional manifolds. To this end, we conceive a general anomaly detection framework called Preference Isolation Forest (PIF), that combines the benefits of adaptive isolation-based methods with the flexibility of preference embedding. The key intuition is to embed the data into a high-dimensional preference space by fitting low-dimensional manifolds, and to identify anomalies as isolated points. We propose three isolation approaches to identify anomalies: $i$) Voronoi-iForest, the most general solution, $ii$) RuzHash-iForest, that avoids explicit computation of distances via Local Sensitive Hashing, and $iii$) Sliding-PIF, that leverages a locality prior to improve efficiency and effectiveness.
title Preference Isolation Forest for Structure-based Anomaly Detection
topic Machine Learning
Artificial Intelligence
Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2505.10876