DMVSVDD: Multi-View Data Novelty Detection with Deep Autoencoding Support Vector Data Description

Abstract

Novelty detection is usually defined as the identification of new or abnormal objects (outliers) from the normal ones (inliers), which has wide potential applications in the real world. Recently, an effective algorithm called Deep Support Vector Data Description (Deep SVDD) has been proposed for novelty detection, which jointly trains a deep neural network while optimizing a data-enclosing hypersphere in output space. However, some constraints such as hypersphere collapse, limit the adaptability of the model and may affect the model performance. Moreover, most of the existing studies concerning Deep SVDD focus on the novelty detection for single-view data, which may fail to provide an accurate and reliable decision because the single-view data sometimes cannot fully reflect the actual condition of the problem. In this study, we developed an end-to-end deep learning method of novelty detection for multi-view data, i.e., the Deep Multi-View SVDD (DMVSVDD). To fully preserve the correlative and complementary information of multi-view data, we jointly trained multiple deep autoencoding neural networks for multiple views while adaptively optimizing the data-enclosing hypersphere of each view in latent space. A global objective function was proposed, which takes both of the sample reconstruction error minimization and the hypersphere volume minimization into consideration simultaneously to prevent hypersphere collapse in the model. In the global objective function, the hypersphere centers and view weights of different views were designed to adaptively select the better representative features after each epoch during the training process by embedding multi-view target samples into multiple data-enclosing hyperspheres with minimum volumes. The experimental results on the MNIST-USPS and NUS-WIDE-OBJECT datasets reveal that our proposed method learns the target class effectively and is superior to some state-of-the-art methods.