Multi-Resolution Continuous Normalizing Flows

TMLR Paper283 Authors

18 Jul 2022 (modified: 28 Feb 2023)Rejected by TMLREveryoneRevisionsBibTeX
Abstract: Recent work has shown that Neural Ordinary Differential Equations (ODEs) can serve as generative models of images using the perspective of Continuous Normalizing Flows (CNFs). Such models offer exact likelihood calculation, and invertible generation/density estimation. In this work we introduce a Multi-Resolution variant of such models (MRCNF), by characterizing the conditional distribution over the additional information required to generate a fine image that is consistent with the coarse image. We introduce a transformation between resolutions that allows for no change in the log likelihood. We show that this approach yields comparable likelihood values for various image datasets, with improved performance at higher resolutions, with fewer parameters, using only one GPU. Further, we examine the out-of-distribution properties of MRCNFs, and find that they are similar to those of other likelihood-based generative models.
Submission Length: Regular submission (no more than 12 pages of main content)
Assigned Action Editor: ~Andrej_Risteski2
Submission Number: 283
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