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Improved Techniques for Training GANs – OpenAI's first paper (arxiv.org)
126 points by gwulf on Jun 14, 2016 | hide | past | pdf | 12 comments on HN

In plain words: A generator and a judge network compete, and new training tricks sharpen that contest to make more realistic images and learn better from few labels. People could not tell generated digits from real ones, and guessed wrong 21.3% of the time on color photos.

Abstract · Improved Techniques for Training GANs

We present a variety of new architectural features and training procedures that we apply to the generative adversarial networks (GANs) framework. We focus on two applications of GANs: semi-supervised learning, and the generation of images that humans find visually realistic. Unlike most work on generative models, our primary goal is not to train a model that assigns high likelihood to test data, nor do we require the model to be able to learn well without using any labels. Using our new techniques, we achieve state-of-the-art results in semi-supervised classification on MNIST, CIFAR-10 and SVHN. The generated images are of high quality as confirmed by a visual Turing test: our model generates MNIST samples that humans cannot distinguish from real data, and CIFAR-10 samples that yield a human error rate of 21.3%. We also present ImageNet samples with unprecedented resolution and show that our methods enable the model to learn recognizable features of ImageNet classes.

Tim Salimans, Ian Goodfellow, Wojciech Zaremba, Vicki Cheung, Alec Radford, Xi Chen
arXiv:1606.03498 · cs.LG, cs.CV, cs.NE · submitted Jun 10, 2016
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So this is pretty interesting.

One of the great hopes of the current deep learning boom is that somehow we will develop unsupervised or at least semi-supervised techniques which can perform close to the great results that are being seen with supervised learning.

Adversarial Networks is one of the more likely routes to semi-supervised. There is also a lot of interesting work in combining Bayesian optimization techniques with Deep Networks to develop one-shot learning[1][2]. Some of this was (very broadly) in response to the the one-shot learning paper coming out of (I've forgotten!!) where the authors are famously doubtful about the utility of Deep Learning, and showed somewhat competitive results on MNIST. (I can't remember who it was - there have been HN discussions about the group. Sorry!!)

Both OpenAI and DeepMind are following roughly similar paths here (no surprise really), and the results are looking really good.

[1] http://arxiv.org/abs/1603.05106

[2] http://arxiv.org/abs/1606.04080

> the one-shot learning paper coming out of (I've forgotten!!) where the authors are famously doubtful about the utility of Deep Learning

This? https://www.technologyreview.com/s/544376/this-ai-algorithm-...

http://cims.nyu.edu/~brenden/LakeEtAl2015Science.pdf

That was it, although I see I've conflated the views of Gary Marcus (who I think it is fair to characterize as anti-Deep Learning[1]) and Lake, Salakhutdinov, and Tenenbaum who wrote the paper.

[1] https://www.technologyreview.com/s/544606/can-this-man-make-...

The paper presents improved techniques for training Generative Adversarial Networks (GANs). Code is published here: https://github.com/openai/improved-gan (uses TensorFlow, Theano, Lasgne)

Nice work team!

When they find the visual turing test results important enough to put in the abstract, it's a shame they only include tiny images in the paper :(
They are the full size images. CIFAR-10 is 32x32 colour images: https://www.cs.toronto.edu/~kriz/cifar.html
This is one of many examples why claims regarding near- or super- human performance in AI papers need to be taken with a good amount of salt. CIFAR-10 is great for experimenting with your algorithms, but it's a horrible dataset to do any kinds of human-to-machine performance comparisons.
If they used another dataset with images of larger dimensions could they generate larger and less blurry images?
A DCGAN as usually implemented (eg Soumith's Torch DCGAN implementation) can produce arbitrarily large images by upscaling. The quality won't be good, though, unsurprisingly, because it was only trained on 32px or less images. This also means that it's hard to evaluate DCGAN improvements because you're stuck squinting at 32px thumbnails trying to guess whether one blur looks more semantically meaningful than another blur.

One nice thing about this paper is that, as I've been suggested for a while, they up the input to 128px for the Imagenet thumbnails, and if you look at those, it immediately pops out that while the DCGAN has in fact successfully learned to construct vaguely dog-like images, the global structure has issues.

What is the license for the paper? I can see it's licensed for Arxiv to distribute, but I cannot see any open access/distribution besides that.

Basically, can I redistribute this paper in my website? if so, under what license?

PS, great job

It would be nice if there was an explicit CC license, but ArXiv has a perpetual license to distribute it, and you can link to ArXiv. Why would you host the paper yourself?

Edit: The code has been published as well, under the MIT license. https://github.com/openai/improved-gan

Why? There could be many reasons, but mine is because I'm doing a small Arxiv alternative. Unfortunately no license means closed with copyright... which I expected OpenAI to know and handle