Small-GAN: Speeding up GAN Training using Core-Sets
Authors: Samarth Sinha, Han Zhang, Anirudh Goyal, Yoshua Bengio, Hugo Larochelle, Augustus Odena
Keywords: GANs, Coreset
TL;DR: We use Core-set sampling to help alleviate the problem of using large mini-batches for GAN training.
Abstract: BigGAN suggests that Generative Adversarial Networks (GANs) benefit disproportionately from large minibatch sizes. This finding is interesting but also discouraging -- large batch sizes  are slow and expensive to emulate on conventional hardware. Thus, it would be nice if there were some trick by which we could generate batches that were effectively big though small in practice. In this work, we propose such a trick, inspired by the use of Coreset-selection in active learning. When training a GAN, we draw a large batch of samples from the prior and then compress that batch using Coreset-selection. To create effectively large batches of real images, we create a cached dataset of Inception activations of each training image, randomly project them down to a smaller dimension, and then use Coreset-selection on those projected embeddings at training time. We conduct experiments showing that this technique substantially reduces training time and memory usage for modern GAN variants, that it reduces the fraction of dropped modes in a synthetic dataset, and that it helps us use GANs to reach a new state of the art in anomaly detection.