Gilbo: One Metric To Measure Them All

We propose a simple, tractable lower bound on the mutual information contained in the joint generative density of any latent variable generative model: the GILBO (Generative Information Lower BOund). It offers a data-independent measure of the complexity of the learned latent variable description, giving the log of the effective description length. It is well-defined for both vAEs and GANs. We compute the GILBO for 800 GANs and VAEs each trained on four datasets (MNIsT, FashionmNIST, ciEAR-10 and CelebA) and discuss the results.