Search Results for author: Guansong Pang

Found 59 papers, 43 papers with code

Weakly-supervised Video Anomaly Detection with Robust Temporal Feature Magnitude Learning

3 code implementations ICCV 2021 Yu Tian, Guansong Pang, Yuanhong Chen, Rajvinder Singh, Johan W. Verjans, Gustavo Carneiro

To address this issue, we introduce a novel and theoretically sound method, named Robust Temporal Feature Magnitude learning (RTFM), which trains a feature magnitude learning function to effectively recognise the positive instances, substantially improving the robustness of the MIL approach to the negative instances from abnormal videos.

Anomaly Detection In Surveillance Videos Contrastive Learning +2

Learning Representations of Ultrahigh-dimensional Data for Random Distance-based Outlier Detection

3 code implementations13 Jun 2018 Guansong Pang, Longbing Cao, Ling Chen, Huan Liu

However, existing unsupervised representation learning methods mainly focus on preserving the data regularity information and learning the representations independently of subsequent outlier detection methods, which can result in suboptimal and unstable performance of detecting irregularities (i. e., outliers).

Anomaly Detection Disease Prediction +3

Deep Weakly-supervised Anomaly Detection

3 code implementations30 Oct 2019 Guansong Pang, Chunhua Shen, Huidong Jin, Anton Van Den Hengel

To detect both seen and unseen anomalies, we introduce a novel deep weakly-supervised approach, namely Pairwise Relation prediction Network (PReNet), that learns pairwise relation features and anomaly scores by predicting the relation of any two randomly sampled training instances, in which the pairwise relation can be anomaly-anomaly, anomaly-unlabeled, or unlabeled-unlabeled.

Relation Semi-supervised Anomaly Detection +3

Deep Anomaly Detection with Deviation Networks

6 code implementations19 Nov 2019 Guansong Pang, Chunhua Shen, Anton Van Den Hengel

Instead of representation learning, our method fulfills an end-to-end learning of anomaly scores by a neural deviation learning, in which we leverage a few (e. g., multiple to dozens) labeled anomalies and a prior probability to enforce statistically significant deviations of the anomaly scores of anomalies from that of normal data objects in the upper tail.

Anomaly Detection Cyber Attack Detection +3

Unsupervised Representation Learning by Predicting Random Distances

2 code implementations22 Dec 2019 Hu Wang, Guansong Pang, Chunhua Shen, Congbo Ma

To enable unsupervised learning on those domains, in this work we propose to learn features without using any labelled data by training neural networks to predict data distances in a randomly projected space.

Anomaly Detection Clustering +1

Deep Isolation Forest for Anomaly Detection

2 code implementations14 Jun 2022 Hongzuo Xu, Guansong Pang, Yijie Wang, Yongjun Wang

Isolation forest (iForest) has been emerging as arguably the most popular anomaly detector in recent years due to its general effectiveness across different benchmarks and strong scalability.

Anomaly Detection Time Series +1

Pixel-wise Energy-biased Abstention Learning for Anomaly Segmentation on Complex Urban Driving Scenes

3 code implementations24 Nov 2021 Yu Tian, Yuyuan Liu, Guansong Pang, Fengbei Liu, Yuanhong Chen, Gustavo Carneiro

However, previous uncertainty approaches that directly associate high uncertainty to anomaly may sometimes lead to incorrect anomaly predictions, and external reconstruction models tend to be too inefficient for real-time self-driving embedded systems.

Ranked #2 on Anomaly Detection on Lost and Found (using extra training data)

Anomaly Detection Segmentation +1

AnomalyCLIP: Object-agnostic Prompt Learning for Zero-shot Anomaly Detection

3 code implementations29 Oct 2023 Qihang Zhou, Guansong Pang, Yu Tian, Shibo He, Jiming Chen

It is a crucial task when training data is not accessible due to various concerns, eg, data privacy, yet it is challenging since the models need to generalize to anomalies across different domains where the appearance of foreground objects, abnormal regions, and background features, such as defects/tumors on different products/organs, can vary significantly.

Anomaly Detection zero-shot anomaly detection +1

Explainable Deep Few-shot Anomaly Detection with Deviation Networks

1 code implementation1 Aug 2021 Guansong Pang, Choubo Ding, Chunhua Shen, Anton Van Den Hengel

Here, we study the problem of few-shot anomaly detection, in which we aim at using a few labeled anomaly examples to train sample-efficient discriminative detection models.

Ranked #5 on Supervised Anomaly Detection on MVTec AD (using extra training data)

Multiple Instance Learning Supervised Anomaly Detection +1

Catching Both Gray and Black Swans: Open-set Supervised Anomaly Detection

1 code implementation CVPR 2022 Choubo Ding, Guansong Pang, Chunhua Shen

Despite most existing anomaly detection studies assume the availability of normal training samples only, a few labeled anomaly examples are often available in many real-world applications, such as defect samples identified during random quality inspection, lesion images confirmed by radiologists in daily medical screening, etc.

Ranked #4 on Supervised Anomaly Detection on MVTec AD (using extra training data)

Supervised Anomaly Detection

Deep One-Class Classification via Interpolated Gaussian Descriptor

2 code implementations25 Jan 2021 Yuanhong Chen, Yu Tian, Guansong Pang, Gustavo Carneiro

The adversarial interpolation is enforced to consistently learn a smooth Gaussian descriptor, even when the training data is small or contaminated with anomalous samples.

Ranked #2 on Anomaly Detection on MNIST (using extra training data)

Classification One-Class Classification +1

VadCLIP: Adapting Vision-Language Models for Weakly Supervised Video Anomaly Detection

1 code implementation22 Aug 2023 Peng Wu, Xuerong Zhou, Guansong Pang, Lingru Zhou, Qingsen Yan, Peng Wang, Yanning Zhang

With the benefit of dual branch, VadCLIP achieves both coarse-grained and fine-grained video anomaly detection by transferring pre-trained knowledge from CLIP to WSVAD task.

Anomaly Detection Binary Classification +1

Toward Generalist Anomaly Detection via In-context Residual Learning with Few-shot Sample Prompts

2 code implementations11 Mar 2024 Jiawen Zhu, Guansong Pang

In this work, we propose to train a GAD model with few-shot normal images as sample prompts for AD on diverse datasets on the fly.

Anomaly Detection

Subgraph Centralization: A Necessary Step for Graph Anomaly Detection

1 code implementation17 Jan 2023 Zhong Zhuang, Kai Ming Ting, Guansong Pang, Shuaibin Song

A treatment called Subgraph Centralization for graph anomaly detection is proposed to address all the above weaknesses.

Graph Anomaly Detection

Calibrated One-class Classification for Unsupervised Time Series Anomaly Detection

1 code implementation25 Jul 2022 Hongzuo Xu, Yijie Wang, Songlei Jian, Qing Liao, Yongjun Wang, Guansong Pang

Our one-class classifier is calibrated in two ways: (1) by adaptively penalizing uncertain predictions, which helps eliminate the impact of anomaly contamination while accentuating the predictions that the one-class model is confident in, and (2) by discriminating the normal samples from native anomaly examples that are generated to simulate genuine time series abnormal behaviors on the basis of original data.

One-Class Classification One-class classifier +2

Constrained Contrastive Distribution Learning for Unsupervised Anomaly Detection and Localisation in Medical Images

1 code implementation5 Mar 2021 Yu Tian, Guansong Pang, Fengbei Liu, Yuanhong Chen, Seon Ho Shin, Johan W. Verjans, Rajvinder Singh, Gustavo Carneiro

Unsupervised anomaly detection (UAD) learns one-class classifiers exclusively with normal (i. e., healthy) images to detect any abnormal (i. e., unhealthy) samples that do not conform to the expected normal patterns.

Contrastive Learning Representation Learning +1

Self-supervised Pseudo Multi-class Pre-training for Unsupervised Anomaly Detection and Segmentation in Medical Images

2 code implementations3 Sep 2021 Yu Tian, Fengbei Liu, Guansong Pang, Yuanhong Chen, Yuyuan Liu, Johan W. Verjans, Rajvinder Singh, Gustavo Carneiro

Pre-training UAD methods with self-supervised learning, based on computer vision techniques, can mitigate this challenge, but they are sub-optimal because they do not explore domain knowledge for designing the pretext tasks, and their contrastive learning losses do not try to cluster the normal training images, which may result in a sparse distribution of normal images that is ineffective for anomaly detection.

Contrastive Learning Data Augmentation +2

Learning Feature Inversion for Multi-class Anomaly Detection under General-purpose COCO-AD Benchmark

1 code implementation16 Apr 2024 Jiangning Zhang, Chengjie Wang, Xiangtai Li, Guanzhong Tian, Zhucun Xue, Yong liu, Guansong Pang, DaCheng Tao

Moreover, current metrics such as AU-ROC have nearly reached saturation on simple datasets, which prevents a comprehensive evaluation of different methods.

Anomaly Detection object-detection +2

Cross-Domain Graph Anomaly Detection via Anomaly-aware Contrastive Alignment

1 code implementation2 Dec 2022 Qizhou Wang, Guansong Pang, Mahsa Salehi, Wray Buntine, Christopher Leckie

In doing so, ACT effectively transfers anomaly-informed knowledge from the source graph to learn the complex node relations of the normal class for GAD on the target graph without any specification of the anomaly distributions.

Contrastive Learning Domain Adaptation +1

Contrastive Transformer-based Multiple Instance Learning for Weakly Supervised Polyp Frame Detection

1 code implementation23 Mar 2022 Yu Tian, Guansong Pang, Fengbei Liu, Yuyuan Liu, Chong Wang, Yuanhong Chen, Johan W Verjans, Gustavo Carneiro

Current polyp detection methods from colonoscopy videos use exclusively normal (i. e., healthy) training images, which i) ignore the importance of temporal information in consecutive video frames, and ii) lack knowledge about the polyps.

Multiple Instance Learning Supervised Anomaly Detection +1

Deep Learning for Hate Speech Detection: A Comparative Study

1 code implementation19 Feb 2022 Jitendra Singh Malik, Hezhe Qiao, Guansong Pang, Anton Van Den Hengel

Automated hate speech detection is an important tool in combating the spread of hate speech, particularly in social media.

Computational Efficiency Domain Generalization +1

Deep Graph-level Anomaly Detection by Glocal Knowledge Distillation

1 code implementation19 Dec 2021 Rongrong Ma, Guansong Pang, Ling Chen, Anton Van Den Hengel

Graph-level anomaly detection (GAD) describes the problem of detecting graphs that are abnormal in their structure and/or the features of their nodes, as compared to other graphs.

Anomaly Detection Knowledge Distillation

Unsupervised Recognition of Unknown Objects for Open-World Object Detection

1 code implementation31 Aug 2023 Ruohuan Fang, Guansong Pang, Lei Zhou, Xiao Bai, Jin Zheng

Open-World Object Detection (OWOD) extends object detection problem to a realistic and dynamic scenario, where a detection model is required to be capable of detecting both known and unknown objects and incrementally learning newly introduced knowledge.

Object object-detection +2

Viral Pneumonia Screening on Chest X-ray Images Using Confidence-Aware Anomaly Detection

1 code implementation27 Mar 2020 Jianpeng Zhang, Yutong Xie, Guansong Pang, Zhibin Liao, Johan Verjans, Wenxin Li, Zongji Sun, Jian He, Yi Li, Chunhua Shen, Yong Xia

In this paper, we formulate the task of differentiating viral pneumonia from non-viral pneumonia and healthy controls into an one-class classification-based anomaly detection problem, and thus propose the confidence-aware anomaly detection (CAAD) model, which consists of a shared feature extractor, an anomaly detection module, and a confidence prediction module.

Binary Classification Classification +2

Truncated Affinity Maximization: One-class Homophily Modeling for Graph Anomaly Detection

1 code implementation NeurIPS 2023 Hezhe Qiao, Guansong Pang

In this work, we explore this property to introduce a novel unsupervised anomaly scoring measure for GAD, local node affinity, that assigns a larger anomaly score to nodes that are less affiliated with their neighbors, with the affinity defined as similarity on node attributes/representations.

Graph Anomaly Detection

Anomaly Detection under Distribution Shift

1 code implementation ICCV 2023 Tri Cao, Jiawen Zhu, Guansong Pang

Anomaly detection (AD) is a crucial machine learning task that aims to learn patterns from a set of normal training samples to identify abnormal samples in test data.

Anomaly Detection

Simple Image-level Classification Improves Open-vocabulary Object Detection

1 code implementation16 Dec 2023 Ruohuan Fang, Guansong Pang, Xiao Bai

This limits their capability in detecting hard objects of small, blurred, or occluded appearance from novel/base categories, whose detection heavily relies on contextual information.

Knowledge Distillation Object +3

Graph-level Anomaly Detection via Hierarchical Memory Networks

1 code implementation3 Jul 2023 Chaoxi Niu, Guansong Pang, Ling Chen

One primary challenge is to learn normal patterns manifested in both fine-grained and holistic views of graphs for identifying graphs that are abnormal in part or in whole.

Anomaly Detection

Anomaly Heterogeneity Learning for Open-set Supervised Anomaly Detection

1 code implementation19 Oct 2023 Jiawen Zhu, Choubo Ding, Yu Tian, Guansong Pang

Extensive experiments on nine real-world anomaly detection datasets show that AHL can 1) substantially enhance different state-of-the-art OSAD models in detecting seen and unseen anomalies, and 2) effectively generalize to unseen anomalies in new domains.

Supervised Anomaly Detection

Out-of-Distribution Detection in Long-Tailed Recognition with Calibrated Outlier Class Learning

1 code implementation17 Dec 2023 Wenjun Miao, Guansong Pang, Tianqi Li, Xiao Bai, Jin Zheng

To this end, we introduce a novel calibrated outlier class learning (COCL) approach, in which 1) a debiased large margin learning method is introduced in the outlier class learning to distinguish OOD samples from both head and tail classes in the representation space and 2) an outlier-class-aware logit calibration method is defined to enhance the long-tailed classification confidence.

Out-of-Distribution Detection

Unraveling the "Anomaly" in Time Series Anomaly Detection: A Self-supervised Tri-domain Solution

1 code implementation19 Nov 2023 Yuting Sun, Guansong Pang, Guanhua Ye, Tong Chen, Xia Hu, Hongzhi Yin

The ongoing challenges in time series anomaly detection (TSAD), notably the scarcity of anomaly labels and the variability in anomaly lengths and shapes, have led to the need for a more efficient solution.

Anomaly Detection Contrastive Learning +3

Unsupervised Anomaly Detection in Medical Images with a Memory-augmented Multi-level Cross-attentional Masked Autoencoder

1 code implementation22 Mar 2022 Yu Tian, Guansong Pang, Yuyuan Liu, Chong Wang, Yuanhong Chen, Fengbei Liu, Rajvinder Singh, Johan W Verjans, Mengyu Wang, Gustavo Carneiro

Our UAD approach, the memory-augmented multi-level cross-attentional masked autoencoder (MemMC-MAE), is a transformer-based approach, consisting of a novel memory-augmented self-attention operator for the encoder and a new multi-level cross-attention operator for the decoder.

Image Reconstruction Unsupervised Anomaly Detection

HRGCN: Heterogeneous Graph-level Anomaly Detection with Hierarchical Relation-augmented Graph Neural Networks

1 code implementation28 Aug 2023 Jiaxi Li, Guansong Pang, Ling Chen, Mohammad-Reza Namazi-Rad

To address the problem, we propose HRGCN, an unsupervised deep heterogeneous graph neural network, to model complex heterogeneous relations between different entities in the system for effectively identifying these anomalous behaviour graphs.

Anomaly Detection Relation

Learning Adversarial Semantic Embeddings for Zero-Shot Recognition in Open Worlds

1 code implementation7 Jul 2023 Tianqi Li, Guansong Pang, Xiao Bai, Jin Zheng, Lei Zhou, Xin Ning

Open-Set Recognition (OSR) is dedicated to addressing the unknown class issue, but existing OSR methods are not designed to model the semantic information of the unseen classes.

Open Set Learning Zero-Shot Learning

Generative Semi-supervised Graph Anomaly Detection

1 code implementation19 Feb 2024 Hezhe Qiao, Qingsong Wen, XiaoLi Li, Ee-Peng Lim, Guansong Pang

This work considers a practical semi-supervised graph anomaly detection (GAD) scenario, where part of the nodes in a graph are known to be normal, contrasting to the unsupervised setting in most GAD studies with a fully unlabeled graph.

Graph Anomaly Detection One-class classifier

Learning Transferable Negative Prompts for Out-of-Distribution Detection

1 code implementation4 Apr 2024 Tianqi Li, Guansong Pang, Xiao Bai, Wenjun Miao, Jin Zheng

Existing prompt learning methods have shown certain capabilities in Out-of-Distribution (OOD) detection, but the lack of OOD images in the target dataset in their training can lead to mismatches between OOD images and In-Distribution (ID) categories, resulting in a high false positive rate.

Out-of-Distribution Detection Out of Distribution (OOD) Detection

Affinity Uncertainty-based Hard Negative Mining in Graph Contrastive Learning

1 code implementation31 Jan 2023 Chaoxi Niu, Guansong Pang, Ling Chen

To tackle this problem, this article proposes a novel approach that builds a discriminative model on collective affinity information (i. e., two sets of pairwise affinities between the negative instances and the anchor instance) to mine hard negatives in GCL.

Contrastive Learning Node Classification

CoLeCLIP: Open-Domain Continual Learning via Joint Task Prompt and Vocabulary Learning

1 code implementation15 Mar 2024 Yukun Li, Guansong Pang, Wei Suo, Chenchen Jing, Yuling Xi, Lingqiao Liu, Hao Chen, Guoqiang Liang, Peng Wang

Large pre-trained VLMs like CLIP have demonstrated superior zero-shot recognition ability, and a number of recent studies leverage this ability to mitigate catastrophic forgetting in CL, but they focus on closed-set CL in a single domain dataset.

Class Incremental Learning Incremental Learning +1

Unified Multifaceted Feature Learning for Person Re-Identification

no code implementations20 Nov 2019 Cheng Yan, Guansong Pang, Xiao Bai, Chunhua Shen

The loss structures the augmented images resulted by the two types of image erasing in a two-level hierarchy and enforces multifaceted attention to different parts.

Person Re-Identification

Self-trained Deep Ordinal Regression for End-to-End Video Anomaly Detection

no code implementations CVPR 2020 Guansong Pang, Cheng Yan, Chunhua Shen, Anton Van Den Hengel, Xiao Bai

Video anomaly detection is of critical practical importance to a variety of real applications because it allows human attention to be focused on events that are likely to be of interest, in spite of an otherwise overwhelming volume of video.

Anomaly Detection regression +2

Deep Learning for Anomaly Detection: A Review

no code implementations6 Jul 2020 Guansong Pang, Chunhua Shen, Longbing Cao, Anton Van Den Hengel

This paper surveys the research of deep anomaly detection with a comprehensive taxonomy, covering advancements in three high-level categories and 11 fine-grained categories of the methods.

Anomaly Detection Novelty Detection +1

Beyond Triplet Loss: Person Re-identification with Fine-grained Difference-aware Pairwise Loss

no code implementations22 Sep 2020 Cheng Yan, Guansong Pang, Xiao Bai, Jun Zhou, Lin Gu

The proposed loss is generic and can be used as a plugin to replace the triplet loss to significantly enhance different types of state-of-the-art approaches.

Person Re-Identification

Deep Depression Prediction on Longitudinal Data via Joint Anomaly Ranking and Classification

no code implementations5 Dec 2020 Guansong Pang, Ngoc Thien Anh Pham, Emma Baker, Rebecca Bentley, Anton Van Den Hengel

A wide variety of methods have been developed for identifying depression, but they focus primarily on measuring the degree to which individuals are suffering from depression currently.

Depression Detection Metric Learning +1

Homophily Outlier Detection in Non-IID Categorical Data

no code implementations21 Mar 2021 Guansong Pang, Longbing Cao, Ling Chen

Most of existing outlier detection methods assume that the outlier factors (i. e., outlierness scoring measures) of data entities (e. g., feature values and data objects) are Independent and Identically Distributed (IID).

feature selection Outlier Detection

DRAM Failure Prediction in AIOps: Empirical Evaluation, Challenges and Opportunities

no code implementations30 Apr 2021 Zhiyue Wu, Hongzuo Xu, Guansong Pang, Fengyuan Yu, Yijie Wang, Songlei Jian, Yongjun Wang

DRAM failure prediction is a vital task in AIOps, which is crucial to maintain the reliability and sustainable service of large-scale data centers.

Multi-class Classification Unsupervised Anomaly Detection

BV-Person: A Large-Scale Dataset for Bird-View Person Re-Identification

no code implementations ICCV 2021 Cheng Yan, Guansong Pang, Lei Wang, Jile Jiao, Xuetao Feng, Chunhua Shen, Jingjing Li

In this work we introduce a new ReID task, bird-view person ReID, which aims at searching for a person in a gallery of horizontal-view images with the query images taken from a bird's-eye view, i. e., an elevated view of an object from above.

Person Re-Identification

Occluded Person Re-Identification With Single-Scale Global Representations

no code implementations ICCV 2021 Cheng Yan, Guansong Pang, Jile Jiao, Xiao Bai, Xuetao Feng, Chunhua Shen

However, real-world ReID applications typically have highly diverse occlusions and involve a hybrid of occluded and non-occluded pedestrians.

Graph Matching Person Re-Identification +1

Background Matters: Enhancing Out-of-distribution Detection with Domain Features

no code implementations15 Mar 2023 Choubo Ding, Guansong Pang, Chunhua Shen

To this end, we propose a novel generic framework that can learn the domain features from the ID training samples by a dense prediction approach, with which different existing semantic-feature-based OOD detection methods can be seamlessly combined to jointly learn the in-distribution features from both the semantic and domain dimensions.

Object Recognition Out-of-Distribution Detection

Feature Prediction Diffusion Model for Video Anomaly Detection

no code implementations ICCV 2023 Cheng Yan, Shiyu Zhang, Yang Liu, Guansong Pang, Wenjun Wang

Motivated by the impressive generative and anti-noise capacity of diffusion model (DM), in this work, we introduce a novel DM-based method to predict the features of video frames for anomaly detection.

Anomaly Detection Denoising +1

Open-Set Graph Anomaly Detection via Normal Structure Regularisation

no code implementations12 Nov 2023 Qizhou Wang, Guansong Pang, Mahsa Salehi, Christopher Leckie

However, current methods tend to over-emphasise fitting the seen anomalies, leading to a weak generalisation ability to detect unseen anomalies, i. e., those that are not illustrated by the labelled anomaly nodes.

Graph Anomaly Detection Supervised Anomaly Detection

Open-Vocabulary Video Anomaly Detection

no code implementations13 Nov 2023 Peng Wu, Xuerong Zhou, Guansong Pang, Yujia Sun, Jing Liu, Peng Wang, Yanning Zhang

Particularly, we devise a semantic knowledge injection module to introduce semantic knowledge from large language models for the detection task, and design a novel anomaly synthesis module to generate pseudo unseen anomaly videos with the help of large vision generation models for the classification task.

Anomaly Detection Video Anomaly Detection

A Survey on Visual Anomaly Detection: Challenge, Approach, and Prospect

no code implementations29 Jan 2024 Yunkang Cao, Xiaohao Xu, Jiangning Zhang, Yuqi Cheng, Xiaonan Huang, Guansong Pang, Weiming Shen

Visual Anomaly Detection (VAD) endeavors to pinpoint deviations from the concept of normality in visual data, widely applied across diverse domains, e. g., industrial defect inspection, and medical lesion detection.

Anomaly Detection Lesion Detection

Graph Continual Learning with Debiased Lossless Memory Replay

no code implementations17 Apr 2024 Chaoxi Niu, Guansong Pang, Ling Chen

Graph continual learning (GCL) tackles this problem by continually adapting GNNs to the expanded graph of the current task while maintaining the performance over the graph of previous tasks.

Continual Learning Incremental Learning

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