Search Results for author: Alexis Arnaudon

Found 13 papers, 5 papers with code

Moment evolution equations and moment matching for stochastic image EPDiff

no code implementations7 Oct 2021 Alexander Christgau, Alexis Arnaudon, Stefan Sommer

Models of stochastic image deformation allow study of time-continuous stochastic effects transforming images by deforming the image domain.

A Unifying and Canonical Description of Measure-Preserving Diffusions

no code implementations6 May 2021 Alessandro Barp, So Takao, Michael Betancourt, Alexis Arnaudon, Mark Girolami

A complete recipe of measure-preserving diffusions in Euclidean space was recently derived unifying several MCMC algorithms into a single framework.

Diffusion bridges for stochastic Hamiltonian systems and shape evolutions

1 code implementation3 Feb 2020 Alexis Arnaudon, Frank van der Meulen, Moritz Schauer, Stefan Sommer

Stochastically evolving geometric systems are studied in shape analysis and computational anatomy for modelling random evolutions of human organ shapes.

Numerical Analysis Computational Engineering, Finance, and Science Numerical Analysis Computational Physics

Semi-supervised classification on graphs using explicit diffusion dynamics

1 code implementation24 Sep 2019 Robert L. Peach, Alexis Arnaudon, Mauricio Barahona

Classification tasks based on feature vectors can be significantly improved by including within deep learning a graph that summarises pairwise relationships between the samples.

Classification General Classification

Selective metamorphosis for growth modelling with applications to landmarks

no code implementations8 Jan 2019 Andreas Bock, Alexis Arnaudon, Colin Cotter

We present a framework for shape matching in computational anatomy allowing users control of the degree to which the matching is diffeomorphic.

Anatomy

Stochastic Image Deformation in Frequency Domain and Parameter Estimation using Moment Evolutions

no code implementations13 Dec 2018 Line Kühnel, Alexis Arnaudon, Tom Fletcher, Stefan Sommer

We apply a stochastic generalisation of the Large Deformation Diffeomorphic Metric Mapping (LDDMM) framework to model differences in the evolution of anatomical objects detected in populations of image data.

Anatomy

String Methods for Stochastic Image and Shape Matching

no code implementations15 May 2018 Alexis Arnaudon, Darryl Holm, Stefan Sommer

Matching of images and analysis of shape differences is traditionally pursued by energy minimization of paths of deformations acting to match the shape objects.

Differential geometry and stochastic dynamics with deep learning numerics

2 code implementations22 Dec 2017 Line Kühnel, Alexis Arnaudon, Stefan Sommer

In this paper, we demonstrate how deterministic and stochastic dynamics on manifolds, as well as differential geometric constructions can be implemented concisely and efficiently using modern computational frameworks that mix symbolic expressions with efficient numerical computations.

Computational Geometry Computation 53A35, 53C17, 53C44, 70H05, 22E30 G.3; G.4; G.1.4

Stochastic metamorphosis with template uncertainties

no code implementations20 Nov 2017 Alexis Arnaudon, Darryl Holm, Stefan Sommer

In this paper, we investigate two stochastic perturbations of the metamorphosis equations of image analysis, in the geometrical context of the Euler-Poincar\'e theory.

Bridge Simulation and Metric Estimation on Landmark Manifolds

no code implementations31 May 2017 Stefan Sommer, Alexis Arnaudon, Line Kuhnel, Sarang Joshi

We present an inference algorithm and connected Monte Carlo based estimation procedures for metric estimation from landmark configurations distributed according to the transition distribution of a Riemannian Brownian motion arising from the Large Deformation Diffeomorphic Metric Mapping (LDDMM) metric.

A Geometric Framework for Stochastic Shape Analysis

1 code implementation29 Mar 2017 Alexis Arnaudon, Darryl D. Holm, Stefan Sommer

We introduce a stochastic model of diffeomorphisms, whose action on a variety of data types descends to stochastic evolution of shapes, images and landmarks.

Image Registration

A Stochastic Large Deformation Model for Computational Anatomy

no code implementations16 Dec 2016 Alexis Arnaudon, Darryl D. Holm, Akshay Pai, Stefan Sommer

In the study of shapes of human organs using computational anatomy, variations are found to arise from inter-subject anatomical differences, disease-specific effects, and measurement noise.

Anatomy

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