Anomaly Detection with Prototype-Guided Discriminative Latent Embeddings

TL;DR

This paper introduces a prototype-guided autoencoder with a discriminative memory module for video anomaly detection, effectively distinguishing normal from abnormal events by emphasizing normal data prototypes.

Contribution

It proposes a novel discriminative memory-enhanced autoencoder with a two-branch structure for improved anomaly detection in videos, leveraging discriminative prototypes and temporal information.

Findings

Outperforms state-of-the-art on three benchmark datasets.

Effectively distinguishes normal and abnormal video frames.

Utilizes a novel discriminative criterion for memory items.

Abstract

Recent efforts towards video anomaly detection (VAD) try to learn a deep autoencoder to describe normal event patterns with small reconstruction errors. The video inputs with large reconstruction errors are regarded as anomalies at the test time. However, these methods sometimes reconstruct abnormal inputs well because of the powerful generalization ability of deep autoencoder. To address this problem, we present a novel approach for anomaly detection, which utilizes discriminative prototypes of normal data to reconstruct video frames. In this way, the model will favor the reconstruction of normal events and distort the reconstruction of abnormal events. Specifically, we use a prototype-guided memory module to perform discriminative latent embedding. We introduce a new discriminative criterion for the memory module, as well as a loss function correspondingly, which can encourage memory items to record the representative embeddings of normal data, i.e. prototypes. Besides, we design a novel two-branch autoencoder, which is composed of a future frame prediction network and an RGB difference generation network that share the same encoder. The stacked RGB difference contains motion information just like optical flow, so our model can learn temporal regularity. We evaluate the effectiveness of our method on three benchmark datasets and experimental results demonstrate the proposed method outperforms the state-of-the-art.