About me

I am a researcher in machine learning for Earth observation. Currently, I'm working on wildfire simulation as a postdoctoral research fellow at CNES in collaboration with the SPE lab from Corsica University and MLIA lab from Sorbonne University. My research focuses on semi/self-supervised multimodal learning and on hybrid modeling (the combination of physical models with machine learning models).

I completed my PhD at ONERA, Magellium and ISAE-SUPAERO in collaboration with the Toulouse Mathematics Institute on the semantic segmentation of airborne hyperspectral images for mapping impermeable surfaces in large urban areas.

News

October 2024: For the third COMET TSI seminar, we were pleased to have a presentation of Nina Maria Gottschling (DLR) about AI hallucinations, no free lunches and the accuracy-stability trade-off in inverse problems!

June 2024: For the second COMET TSI seminar, we were very glad to have Jean Prost talking about his work on posterior sampling for diverse super-resolution with a hierarchical VAE prior! Slides available soon.

May 2024: With colleagues from the COMET TSI, we are starting monthly scientific seminars! The first talk about multi-modal pretraining for Earth observation will be given by Valerio Marsocci on May 21. Slides available soon.

May 2024: I will be at ICLR 2024 for the ML4RS workshop! [paper] [code]

November 2023: I am very glad to have successfully defended my PhD! Huge thanks to my supervisors, to Pr. Céline Hudelot and Pr. Paolo Gamba who reviewed my manuscript, and to all jury members, Yuliya Tarabalka, Karteek Alahari and Patrick Gallinari.

March 2023: I was very glad to present our research work on active learning and hybrid modeling to improve representation learning at OMP. [slides] [video]


Publications

Data sets comparison Toulouse Hyperspectral Data Set: a benchmark data set to assess semi-supervised spectral representation learning and pixel-wise classification techniques
R. Thoreau, L. Risser, V. Achard, B. Berthelot and X. Briottet

ISPRS Journal of Photogrammetry and Remote Sensing.

[paper] [data set] [code] [arXiv]

p3VAE archirecure p3VAE: a physics-integrated generative model. Application to the pixel-wise classification of airborne hyperspectral images
R. Thoreau, L. Risser, V. Achard, B. Berthelot and X. Briottet

Submitted to Springer Machine Learning.

[arXiv] [code]

AL strategies Active Learning for Hyperspectral Image Classification: a Comparative Review
R. Thoreau, V. Achard, L. Risser, B. Berthelot and X. Briottet

IEEE Geoscience and Remote Sensing Magazine.

[paper] [code]

Conference proceedings

Hierarchical nomenclature Probabilistic Breaking Tie: An Active Learning Strategy To Leverage Class Hierarchy For Impervious Surfaces Classification
R. Thoreau, V. Achard, L. Risser, B. Berthelot and X. Briottet

IEEE WHISPERS 2022.

[paper] [code]

Preprocessing illustration Active Learning on Large Hyperspectral Datasets: a Preprocessing Method
R. Thoreau, V. Achard, L. Risser, B. Berthelot and X. Briottet

ISPRS Congress 2022.

[paper] [code]

HSI illustration Hyperspectral Classification Based on Spectral Indices Learned Through Soft Attention Units
R. Thoreau, V. Achard, L. Risser, B. Berthelot and X. Briottet

IEEE IGARSS 2021.

[paper] [code]

Teaching

I'm currently giving lectures about machine learning for the MAPI3 master at Paul Sabatier University.
Past courses from 2020 to 2023
  • Introduction to statistics (lectures) at Paul Sabatier University, 2nd year BS in Biochemistry,
  • Integration and probability theory (tutorials) at ENSEEIHT engineering school,
  • Statistical foundations of Machine Learning (practical works) at ISAE-SUPAERO, Data & Decision Sciences MS,
  • Combinatorial optimization (practical works) at Paul Sabatier University, Computer Science MS,
  • Algorithmic (practical works) at Paul Sabatier University, Computer Science BS,
  • Introduction to python (practical works) at Paul Sabatier University, Civil Engineering BS.

Student supervision

  • March to August 2023, Arthur Cassou, final-year student at ENSTA Bretagne on the integration of physical priors in generative models for hyperspectral data, in collaboration with Laurent Risser, Véronique Achard and Xavier Briottet.
  • May to July 2022, Gaspard Loupit, second-year student at ISAE-SUPAERO on the comparison of features extracted by spatial-spectral convolutions to morphological profiles through LIME explanations for hyperspectral images, in collaboration with Véronique Achard.
  • April to July 2022, Clément Lefranc, master student in computer science at Paul Sabatier University on the development of a QGIS plug-in for active learning on Earth observation data, namely AL4EO.

Resume

Short vitae

Community service & Scientific mediation

  • 2021 - 2022: PhD students representative at SDU2E.
  • Occasional participations to DECLICS meetings with high school students to promote scientific research.
  • Reviewer for IEEE Transactions on Image Processing, MDPI Remote Sensing, MDPI Electronics and MDPI Symmetry. See my records here.