Negative Sampling in Variational Autoencoders

10/07/2019

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by   Adrián Csiszárik, et al.

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23

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We propose negative sampling as an approach to improve the notoriously bad out-of-distribution likelihood estimates of Variational Autoencoder models. Our model pushes latent images of negative samples away from the prior. When the source of negative samples is an auxiliary dataset, such a model can vastly improve on baselines when evaluated on OOD detection tasks. Perhaps more surprisingly, we present a fully unsupervised variant that can also significantly improve detection performance: using the output of the generator as negative samples results in a fully unsupervised model that can be interpreted as adversarially trained.