Momentum Contrastive Autoencoder: Using Contrastive Learning for Latent Space Distribution Matching in WAE

TL;DR

This paper introduces a novel approach called Momentum Contrastive Autoencoder that leverages contrastive learning to improve latent space distribution matching in Wasserstein autoencoders, resulting in faster convergence and higher quality image generation.

Contribution

It proposes using contrastive learning to enhance latent space matching in WAE, achieving more stable training and better image quality.

Findings

Faster convergence compared to existing algorithms

More stable optimization process

Improved FID scores and image realism

Abstract

Wasserstein autoencoder (WAE) shows that matching two distributions is equivalent to minimizing a simple autoencoder (AE) loss under the constraint that the latent space of this AE matches a pre-specified prior distribution. This latent space distribution matching is a core component of WAE, and a challenging task. In this paper, we propose to use the contrastive learning framework that has been shown to be effective for self-supervised representation learning, as a means to resolve this problem. We do so by exploiting the fact that contrastive learning objectives optimize the latent space distribution to be uniform over the unit hyper-sphere, which can be easily sampled from. We show that using the contrastive learning framework to optimize the WAE loss achieves faster convergence and more stable optimization compared with existing popular algorithms for WAE. This is also reflected in the FID scores on CelebA and CIFAR-10 datasets, and the realistic generated image quality on the CelebA-HQ dataset.