DS-UI: Dual-Supervised Mixture of Gaussian Mixture Models for Uncertainty Inference
This work provides an incremental improvement in uncertainty inference for deep neural networks, primarily benefiting researchers and practitioners in image recognition who require more reliable uncertainty estimates.
This paper introduces DS-UI, a dual-supervised uncertainty inference framework that integrates a mixture of Gaussian mixture models (MoGMM) with a deep neural network's classifier to directly calculate probability densities of features. This method significantly outperforms state-of-the-art uncertainty inference techniques in misclassification detection and shows statistically significant improvements in open-set out-of-domain/-distribution detection.
This paper proposes a dual-supervised uncertainty inference (DS-UI) framework for improving Bayesian estimation-based uncertainty inference (UI) in deep neural network (DNN)-based image recognition. In the DS-UI, we combine the classifier of a DNN, i.e., the last fully-connected (FC) layer, with a mixture of Gaussian mixture models (MoGMM) to obtain an MoGMM-FC layer. Unlike existing UI methods for DNNs, which only calculate the means or modes of the DNN outputs' distributions, the proposed MoGMM-FC layer acts as a probabilistic interpreter for the features that are inputs of the classifier to directly calculate the probability density of them for the DS-UI. In addition, we propose a dual-supervised stochastic gradient-based variational Bayes (DS-SGVB) algorithm for the MoGMM-FC layer optimization. Unlike conventional SGVB and optimization algorithms in other UI methods, the DS-SGVB not only models the samples in the specific class for each Gaussian mixture model (GMM) in the MoGMM, but also considers the negative samples from other classes for the GMM to reduce the intra-class distances and enlarge the inter-class margins simultaneously for enhancing the learning ability of the MoGMM-FC layer in the DS-UI. Experimental results show the DS-UI outperforms the state-of-the-art UI methods in misclassification detection. We further evaluate the DS-UI in open-set out-of-domain/-distribution detection and find statistically significant improvements. Visualizations of the feature spaces demonstrate the superiority of the DS-UI.