Annealed Denoising score matching: learning Energy based model in high-dimensional spaces
Authors: Zengyi Li, Yubei Chen, Friedrich T. Sommer
Keywords: Energy based models, score matching, annealing, likelihood, generative model, unsupervised learning
TL;DR: Learned energy based model with score matching
Abstract: Energy  based  models  outputs  unmormalized  log-probability  values  given  datasamples.  Such a estimation is essential in a variety of application problems suchas sample generation, denoising, sample restoration, outlier detection, Bayesianreasoning, and many more.  However, standard maximum likelihood training iscomputationally expensive due to the requirement of sampling model distribution.Score matching potentially alleviates this problem, and denoising score matching(Vincent, 2011) is a particular convenient version.  However,  previous attemptsfailed to produce models capable of high quality sample synthesis.  We believethat  it  is  because  they  only  performed  denoising  score  matching  over  a  singlenoise scale. To overcome this limitation, here we instead learn an energy functionusing all noise scales.   When sampled using Annealed Langevin dynamics andsingle step denoising jump, our model produced high-quality samples comparableto state-of-the-art techniques such as GANs, in addition to assigning likelihood totest data comparable to previous likelihood models.  Our model set a new sam-ple quality baseline in likelihood-based models.  We further demonstrate that our model learns sample distribution and generalize well on an image inpainting tasks.