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Variational Lossy Autoencoder (arxiv.org)
46 points by matk on Nov 10, 2016 | hide | past | pdf | 1 comment on HN

In plain words: This system squeezes data into a short code that keeps only global structure, like an image's shape, and drops texture, while a step-by-step predictor fills in details. It beat earlier models at judging how likely each image is on MNIST, OMNIGLOT, and Caltech-101 Silhouettes.

Abstract

Representation learning seeks to expose certain aspects of observed data in a learned representation that's amenable to downstream tasks like classification. For instance, a good representation for 2D images might be one that describes only global structure and discards information about detailed texture. In this paper, we present a simple but principled method to learn such global representations by combining Variational Autoencoder (VAE) with neural autoregressive models such as RNN, MADE and PixelRNN/CNN. Our proposed VAE model allows us to have control over what the global latent code can learn and , by designing the architecture accordingly, we can force the global latent code to discard irrelevant information such as texture in 2D images, and hence the VAE only "autoencodes" data in a lossy fashion. In addition, by leveraging autoregressive models as both prior distribution $p(z)$ and decoding distribution $p(x|z)$, we can greatly improve generative modeling performance of VAEs, achieving new state-of-the-art results on MNIST, OMNIGLOT and Caltech-101 Silhouettes density estimation tasks.

Xi Chen, Diederik P. Kingma, Tim Salimans, Yan Duan, Prafulla Dhariwal, John Schulman, Ilya Sutskever, Pieter Abbeel
arXiv:1611.02731 · cs.LG, stat.ML · submitted Nov 8, 2016 · updated Mar 4, 2017
abstract · pdf · html · Added CIFAR10 experiments; ICLR 2017

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I'd expect Open AI (7/8 authors affiliated) to have open-source code associated with their publications, but this paper doesn't seem to have any link to code and their github page doesn't seem to have a repo associated with the project.

I thought the point of Open AI was that they be open (from their front page: "we seek to broadcast our work to the world") so it would be good if they could release code associated with their experiments.