A variational approach to nonlocal image restoration flows

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Prasad, Harsh, Tewary, Vivek
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916449475362816
author Prasad, Harsh
Tewary, Vivek
author_facet Prasad, Harsh
Tewary, Vivek
contents We prove existence, uniqueness and initial time regularity for variational solutions to nonlocal total variation flows associated with image denoising and deblurring. In particular, we prove existence of parabolic minimisers $u$, that is, $$\int_0^T\int_Ωu\partial_tϕ\,dx + \textbf{F}(u(t))\,dt\leq \int_0^T \textbf{F}(u+ϕ)(t)\,dt,$$ for $ϕ\in C^\infty_c(Ω\times (0,T))$. The prototypical functional $\textbf{F}(u)$ is $\textbf{F}(u)=\textbf{TV}^α_{\cdot}(u)+\fracκζ\int_Ω|u(x)-u_0(x)|^ζ\,dx$ for $ζ\geq 1$. Here $\textbf{TV}^α_{\cdot}$ is a fractional total variation of either the Riesz or the Gagliardo type and the second term is a regression term. These models are based on different definitions of fractional $\textbf{BV}$ spaces that have been proposed in the literature. The notion of solution is completely variational and based on the weighted dissipation method. We demonstrate existence without smoothness assumptions on the domain and exhibit uniqueness without using strict convexity. We can also deal with fairly general fidelity or regression terms in the model. Furthermore, the method also provides a novel route to constructing solutions of the parabolic fractional $1$-Laplace equation.
format Preprint
id arxiv_https___arxiv_org_abs_2410_17649
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A variational approach to nonlocal image restoration flows
Prasad, Harsh
Tewary, Vivek
Analysis of PDEs
94A08, 68U10, 35K51, 35A01, 35A15, 35R11, 49J40
We prove existence, uniqueness and initial time regularity for variational solutions to nonlocal total variation flows associated with image denoising and deblurring. In particular, we prove existence of parabolic minimisers $u$, that is, $$\int_0^T\int_Ωu\partial_tϕ\,dx + \textbf{F}(u(t))\,dt\leq \int_0^T \textbf{F}(u+ϕ)(t)\,dt,$$ for $ϕ\in C^\infty_c(Ω\times (0,T))$. The prototypical functional $\textbf{F}(u)$ is $\textbf{F}(u)=\textbf{TV}^α_{\cdot}(u)+\fracκζ\int_Ω|u(x)-u_0(x)|^ζ\,dx$ for $ζ\geq 1$. Here $\textbf{TV}^α_{\cdot}$ is a fractional total variation of either the Riesz or the Gagliardo type and the second term is a regression term. These models are based on different definitions of fractional $\textbf{BV}$ spaces that have been proposed in the literature. The notion of solution is completely variational and based on the weighted dissipation method. We demonstrate existence without smoothness assumptions on the domain and exhibit uniqueness without using strict convexity. We can also deal with fairly general fidelity or regression terms in the model. Furthermore, the method also provides a novel route to constructing solutions of the parabolic fractional $1$-Laplace equation.
title A variational approach to nonlocal image restoration flows
topic Analysis of PDEs
94A08, 68U10, 35K51, 35A01, 35A15, 35R11, 49J40
url https://arxiv.org/abs/2410.17649