Flow-GAN: Combining Maximum Likelihood and Adversarial Learning in Generative Models


  • Aditya Grover Stanford University
  • Manik Dhar Stanford University
  • Stefano Ermon Stanford University




generative models, adversarial learning, unsupervised learning, maximum likelihood estimation, normalizing flow models


Adversarial learning of probabilistic models has recently emerged as a promising alternative to maximum likelihood. Implicit models such as generative adversarial networks (GAN) often generate better samples compared to explicit models trained by maximum likelihood. Yet, GANs sidestep the characterization of an explicit density which makes quantitative evaluations challenging. To bridge this gap, we propose Flow-GANs, a generative adversarial network for which we can perform exact likelihood evaluation, thus supporting both adversarial and maximum likelihood training. When trained adversarially, Flow-GANs generate high-quality samples but attain extremely poor log-likelihood scores, inferior even to a mixture model memorizing the training data; the opposite is true when trained by maximum likelihood. Results on MNIST and CIFAR-10 demonstrate that hybrid training can attain high held-out likelihoods while retaining visual fidelity in the generated samples.




How to Cite

Grover, A., Dhar, M., & Ermon, S. (2018). Flow-GAN: Combining Maximum Likelihood and Adversarial Learning in Generative Models. Proceedings of the AAAI Conference on Artificial Intelligence, 32(1). https://doi.org/10.1609/aaai.v32i1.11829