Optical flow estimation with subgrid model for study of turbulent flow
type: Dataset
description: The objective of this thesis is to study the evolution of scalar field carried by a flow from a temporal image sequence. The estimation of the velocity field of turbulent flow is of major importance for understanding the physical phenomenon. Up to now the problem of turbulence is generally ignored in the flow equation of existing methods. An information given by image is discrete at pixel size. Depending on the turbulent rate of the flow, pixel and time resolutions may become too large to neglect the effect of sub-pixel small-scales on the pixel velocity field. For this, we propose a flow equation defined by a filtered concentration transport equation where a classic turbulent sub-grid eddy viscosity model is introduced in order to account for this effect. To formulate the problem, we use a Markovian approach. An unwarping multiresolution by pyramidal decomposition is proposed which reduces the number of operations on images. The optimization coupled with a multigrid approach allows to estimate the optimal 2D real velocity field. Our approach is tested on synthetic andreal image sequences (PIV laboratory experiment and remote sensing data of dust storm event) with high Reynolds number. Comparisons with existing approaches are very promising.
identifier: NNT: 2011ECDL0010
issued: 2026-05-26T14:13:46.127030
language: en
modified: 2026-05-26T14:13:46.127038
contact point: Organization
  fn: CCSD
keyword: estimation-du-mouvement
keyword: flot-optique
keyword: infoeu-reposemanticsdoctoralthesis
keyword: les
keyword: modele-sous-maille
keyword: motion-estimation
keyword: mrf
keyword: optical-flow
keyword: optimisation
keyword: optimization
keyword: spiotherengineering-sciences-physicsother
keyword: subgrid-scale-model
keyword: theses
landing page: https://theses.hal.science/tel-00674772

Optical flow estimation with subgrid model for study of turbulent flow
type: Distribution
format: HTML
issued: 2026-05-26T14:13:46.241225
modified: 2026-05-26T14:13:46.077650
access URL: https://theses.hal.science/tel-00674772

test_moissonnage_selune
type: Agent