ANR ROOT: RegressiOn with Optimal Transport, for computer graphics and vision


Aug. 2016 - Sept. 2021


Presentation

ROOT is a project funded by the ANR throught the young researchers program JCJC. ROOT aims at developping numerical methods for solving regression problems involving optimal transport, with applications in computer graphics and vision. These problems include data fitting, supervised or unsupervised learning, or statistical inference, applied to histogram features.

Histograms are frequently encountered in computer graphics (e.g., reflectance functions, color palettes, distance histograms etc.) and vision (e.g., SIFT or HoG descriptors). Optimal transport offers a framework with a meaningful way of comparing histograms as the amount of work required to move a pile of sand representing one histogram to match another. It also proposes a way of interpolating histograms as the intermediate distribution produced during this motion.

The ROOT project explores the use of optimal transport, but, as a metric in the context of inverse problems for graphics and vision, and machine learning. Challenges addressed by ROOT include:

- Computationally efficient optimal transport solvers between histograms, for use within regression iterations.

- Solving inverse problems in graphics and vision involving histograms via regressions within the optimal transport framework.

Team

Permanents

- Nicolas Bonneel (LIRIS, coordinator)
- Gabriel Peyré (ENS)
- Marco Cuturi (CREST - ENSAE)
- Bruno Lévy (INRIA Nancy Grand-Est)
- David Coeurjolly (LIRIS)
- Julie Digne (LIRIS)

Students

- Matthieu Heitz (PhD student, started Oct. 2016 ; supervision: N. Bonneel, D. Coeurjolly, G. Peyré, M. Cuturi)
- Agathe Herrou (PhD student, started in Sept. 2018 ; supervision: N.Bonneel, J. Digne, B. Lévy).
- Guillaume Cherreau (Master's student ; supervision: N. Bonneel, J. Digne, F. Santambrogio).
- Julien Lacombe (Master's student ; supervision: N. Bonneel, J. Digne).

Publications

Nicolas Bonneel, David Coeurjolly
SPOT: Sliced Partial Optimal Transport
ACM Transactions on Graphics (SIGGRAPH), July 2019

Paper Video Code Project Page Bibtex
Morgan A. Schmitz, Matthieu Heitz, Nicolas Bonneel, Fred Maurice Ngolè Mboula, David Coeurjolly, Marco Cuturi, Gabriel Peyré, Jean-Luc Starck
Wasserstein Dictionary Learning: Optimal Transport-based unsupervised non-linear dictionary learning
SIAM Journal on Imaging Sciences (SIIMS) (2018, to appear)

Preprint Bibtex
Morgan A. Schmitz, Matthieu Heitz, Nicolas Bonneel, Fred Maurice Ngolè Mboula, David Coeurjolly, Marco Cuturi, Gabriel Peyré, Jean-Luc Starck
Optimal transport-based dictionary learning and its application to Euclid-like Point Spread Function representation
SPIE Wavelets and Sparsity XVII

Paper Poster Bibtex