On the Posterior Distribution in Denoising: Application to Uncertainty Quantification

Fuente: arXiv
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Main Authors: Manor, Hila, Michaeli, Tomer
Format: Preprint
Published: 2023
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author Manor, Hila
Michaeli, Tomer
author_facet Manor, Hila
Michaeli, Tomer
contents Denoisers play a central role in many applications, from noise suppression in low-grade imaging sensors, to empowering score-based generative models. The latter category of methods makes use of Tweedie's formula, which links the posterior mean in Gaussian denoising (\ie the minimum MSE denoiser) with the score of the data distribution. Here, we derive a fundamental relation between the higher-order central moments of the posterior distribution, and the higher-order derivatives of the posterior mean. We harness this result for uncertainty quantification of pre-trained denoisers. Particularly, we show how to efficiently compute the principal components of the posterior distribution for any desired region of an image, as well as to approximate the full marginal distribution along those (or any other) one-dimensional directions. Our method is fast and memory-efficient, as it does not explicitly compute or store the high-order moment tensors and it requires no training or fine tuning of the denoiser. Code and examples are available on the project webpage in https://hilamanor.github.io/GaussianDenoisingPosterior/ .
format Preprint
id arxiv_https___arxiv_org_abs_2309_13598
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On the Posterior Distribution in Denoising: Application to Uncertainty Quantification
Manor, Hila
Michaeli, Tomer
Computer Vision and Pattern Recognition
Machine Learning
Denoisers play a central role in many applications, from noise suppression in low-grade imaging sensors, to empowering score-based generative models. The latter category of methods makes use of Tweedie's formula, which links the posterior mean in Gaussian denoising (\ie the minimum MSE denoiser) with the score of the data distribution. Here, we derive a fundamental relation between the higher-order central moments of the posterior distribution, and the higher-order derivatives of the posterior mean. We harness this result for uncertainty quantification of pre-trained denoisers. Particularly, we show how to efficiently compute the principal components of the posterior distribution for any desired region of an image, as well as to approximate the full marginal distribution along those (or any other) one-dimensional directions. Our method is fast and memory-efficient, as it does not explicitly compute or store the high-order moment tensors and it requires no training or fine tuning of the denoiser. Code and examples are available on the project webpage in https://hilamanor.github.io/GaussianDenoisingPosterior/ .
title On the Posterior Distribution in Denoising: Application to Uncertainty Quantification
topic Computer Vision and Pattern Recognition
Machine Learning
url https://arxiv.org/abs/2309.13598