Free-Boundary Quasiconformal Maps via a Least-squares Operator in Diffeomorphism Optimization

Fuente: arXiv
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Main Authors: Xu, Zhehao, Lui, Lok Ming
Format: Preprint
Published: 2025
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_version_ 1866910017274249216
author Xu, Zhehao
Lui, Lok Ming
author_facet Xu, Zhehao
Lui, Lok Ming
contents Free-boundary diffeomorphism optimization, an important and widely occurring task in geometric modeling, computer graphics, and biological imaging, requires simultaneously determining a planar target domain and a locally bijective map with well-controlled distortion. We formulate this task through the least-squares quasiconformal (LSQC) operator and establish key structural properties of the LSQC minimizer, including well-posedness under mild conditions, invariance under similarity transformations, and resolution-independent behavior with stability under mesh refinement. We further analyze the sensitivity of the LSQC solution with respect to the Beltrami coefficient, establishing stability and differentiability properties that enable gradient-based optimization over the space of Beltrami coefficients. To make this differentiable formulation practical at scale and to facilitate the optimization process, we introduce the Spectral Beltrami Network (SBN), a multiscale mesh-spectral surrogate that approximates the LSQC solution operator in a single differentiable forward pass. This yields SBN-Opt, an optimization framework that searches over admissible Beltrami coefficients and pinning conditions to solve free-boundary diffeomorphism objectives with explicit distortion control. Extensive experiments on equiareal parameterization and inconsistent surface registration demonstrate consistent improvements over traditional numerical algorithms.
format Preprint
id arxiv_https___arxiv_org_abs_2511_11679
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Free-Boundary Quasiconformal Maps via a Least-squares Operator in Diffeomorphism Optimization
Xu, Zhehao
Lui, Lok Ming
Machine Learning
Computer Vision and Pattern Recognition
Graphics
Complex Variables
Differential Geometry
30C62, 65D18, 65K10, 68T07
Free-boundary diffeomorphism optimization, an important and widely occurring task in geometric modeling, computer graphics, and biological imaging, requires simultaneously determining a planar target domain and a locally bijective map with well-controlled distortion. We formulate this task through the least-squares quasiconformal (LSQC) operator and establish key structural properties of the LSQC minimizer, including well-posedness under mild conditions, invariance under similarity transformations, and resolution-independent behavior with stability under mesh refinement. We further analyze the sensitivity of the LSQC solution with respect to the Beltrami coefficient, establishing stability and differentiability properties that enable gradient-based optimization over the space of Beltrami coefficients. To make this differentiable formulation practical at scale and to facilitate the optimization process, we introduce the Spectral Beltrami Network (SBN), a multiscale mesh-spectral surrogate that approximates the LSQC solution operator in a single differentiable forward pass. This yields SBN-Opt, an optimization framework that searches over admissible Beltrami coefficients and pinning conditions to solve free-boundary diffeomorphism objectives with explicit distortion control. Extensive experiments on equiareal parameterization and inconsistent surface registration demonstrate consistent improvements over traditional numerical algorithms.
title Free-Boundary Quasiconformal Maps via a Least-squares Operator in Diffeomorphism Optimization
topic Machine Learning
Computer Vision and Pattern Recognition
Graphics
Complex Variables
Differential Geometry
30C62, 65D18, 65K10, 68T07
url https://arxiv.org/abs/2511.11679