Frame-constrained Total Variation Regularization for White Noise Regression

Fuente: arXiv
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Auteurs principaux: del Álamo, Miguel, Li, Housen, Munk, Axel
Format: Preprint
Publié: 2018
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author del Álamo, Miguel
Li, Housen
Munk, Axel
author_facet del Álamo, Miguel
Li, Housen
Munk, Axel
contents Despite the popularity and practical success of total variation (TV) regularization for function estimation, surprisingly little is known about its theoretical performance in a statistical setting. While TV regularization has been known for quite some time to be minimax optimal for denoising one-dimensional signals, for higher dimensions this remains elusive until today. In this paper we consider frame-constrained TV estimators including many well-known (overcomplete) frames in a white noise regression model, and prove their minimax optimality w.r.t. $L^q$-risk ($1\leq q<\infty$) up to a logarithmic factor in any dimension $d\geq 1$. Overcomplete frames are an established tool in mathematical imaging and signal recovery, and their combination with TV regularization has been shown to give excellent results in practice, which our theory now confirms. Our results rely on a novel connection between frame-constraints and certain Besov norms, and on an interpolation inequality to relate them to the risk functional.
format Preprint
id arxiv_https___arxiv_org_abs_1807_02038
institution arXiv
publishDate 2018
record_format arxiv
spellingShingle Frame-constrained Total Variation Regularization for White Noise Regression
del Álamo, Miguel
Li, Housen
Munk, Axel
Statistics Theory
62G05, 62M40, 62G20
Despite the popularity and practical success of total variation (TV) regularization for function estimation, surprisingly little is known about its theoretical performance in a statistical setting. While TV regularization has been known for quite some time to be minimax optimal for denoising one-dimensional signals, for higher dimensions this remains elusive until today. In this paper we consider frame-constrained TV estimators including many well-known (overcomplete) frames in a white noise regression model, and prove their minimax optimality w.r.t. $L^q$-risk ($1\leq q<\infty$) up to a logarithmic factor in any dimension $d\geq 1$. Overcomplete frames are an established tool in mathematical imaging and signal recovery, and their combination with TV regularization has been shown to give excellent results in practice, which our theory now confirms. Our results rely on a novel connection between frame-constraints and certain Besov norms, and on an interpolation inequality to relate them to the risk functional.
title Frame-constrained Total Variation Regularization for White Noise Regression
topic Statistics Theory
62G05, 62M40, 62G20
url https://arxiv.org/abs/1807.02038