Towards Visually Explaining Variational Autoencoders

Recent advances in Convolutional Neural Network (CNN) model interpretability have led to impressive progress in visualizing and understanding model predictions. In particular, gradient-based visual attention methods have driven much recent effort in using visual attention maps as a means for visual explanations. A key problem, however, is these methods are designed for classification and categorization tasks, and their extension to explaining generative models, e.g. variational autoencoders (VAE) is not trivial. In this work, we take a step towards bridging this crucial gap, proposing the first technique to visually explain VAEs by means of gradient-based attention. We present methods to generate visual attention from the learned latent space, and also demonstrate such attention explanations serve more than just explaining VAE predictions. We show how these attention maps can be used to localize anomalies in images, demonstrating state-of-the-art performance on the MVTec-AD dataset. We also show how they can be infused into model training, helping bootstrap the VAE into learning improved latent space disentanglement, demonstrated on the Dsprites dataset

Towards Disentangled Representations via Variational Sparse Coding

International audienceWe present a framework for learning disentangled representations with variational autoencoders in an unsupervised manner, which explicitly imposes sparsity and interpretability of the latent encodings. Leveraging ideas from Sparse Coding models, we consider the Spike and Slab prior distribution for the latent variables, and a modification of the ELBO, inspired by β-VAE model to enforce decomposability over the latent representation. We run our proposed model in a variety of quantitative and qualitative experiments for MNIST, Fashion-MNIST, CelebA and dSprites datasets, showing that the framework disentangles the latent space in continuous sparse interpretable factors and is competitive with current disentangling models