论文标题
用于异常检测的多分辨率知识蒸馏
Multiresolution Knowledge Distillation for Anomaly Detection
论文作者
论文摘要
事实证明,无监督的表示学习是图像中异常检测/定位的关键组成部分。学习这样的表示的挑战是两个方面。首先,样本量通常不够大,无法通过传统技术学习丰富的普遍表示。其次,虽然仅在训练中可用正常样本,但学习的特征应歧视正常和异常样品。在这里,我们建议将在ImageNet上预先训练的专家网络的各个层的特征的“蒸馏”中用于更简单的克隆网络来解决这两个问题。我们使用专家和克隆人网络的中间激活值之间的差异来检测和本地化异常。我们表明,与仅利用上一层激活值相比,考虑到蒸馏中多个中间提示会更好地利用专家的知识和更独特的差异。值得注意的是,以前的方法要么在精确的异常定位中失败,要么需要昂贵的基于区域的培训。相比之下,在不需要任何特殊或密集的培训程序的情况下,我们将可解释性算法纳入了我们的新型框架以用于本次区域的本地化框架。尽管与MNIST,F-MNIST,CIFAR-10,MVTECAD,MVTECAD,VERINAL-OCT和两个医学数据集相比,一些测试数据集和ImageNet之间的对比度存在鲜明的对比,但我们取得了竞争性或显着的结果。
Unsupervised representation learning has proved to be a critical component of anomaly detection/localization in images. The challenges to learn such a representation are two-fold. Firstly, the sample size is not often large enough to learn a rich generalizable representation through conventional techniques. Secondly, while only normal samples are available at training, the learned features should be discriminative of normal and anomalous samples. Here, we propose to use the "distillation" of features at various layers of an expert network, pre-trained on ImageNet, into a simpler cloner network to tackle both issues. We detect and localize anomalies using the discrepancy between the expert and cloner networks' intermediate activation values given the input data. We show that considering multiple intermediate hints in distillation leads to better exploiting the expert's knowledge and more distinctive discrepancy compared to solely utilizing the last layer activation values. Notably, previous methods either fail in precise anomaly localization or need expensive region-based training. In contrast, with no need for any special or intensive training procedure, we incorporate interpretability algorithms in our novel framework for the localization of anomalous regions. Despite the striking contrast between some test datasets and ImageNet, we achieve competitive or significantly superior results compared to the SOTA methods on MNIST, F-MNIST, CIFAR-10, MVTecAD, Retinal-OCT, and two Medical datasets on both anomaly detection and localization.