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Guillaume Astruc

@gastruc.bsky.social
376 followers 79 following 24 posts

2nd Year PhD Student from Imagine-ENPC/IGN/CNES Working on Self-supervised Cross-modal Geospatial Learning. Personal WebPage: gastruc.github.io

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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
🤝 Work with @yohannper.bsky.social , @nicaogr.bsky.social , Clement Mallet & @loicland.bsky.social . Check it out, feedback welcome! 🙌 🌐 Webpage: gastruc.github.io/universat 📄 arXiv: arxiv.org/abs/2606.23503 💻 Code: github.com/gastruc/Univ... 🤗 Model: huggingface.co/g-astruc/Uni...
gastruc.github.io
UniverSat: Resolution- and Modality-Agnostic Transformers for Earth Observation
UniverSat is a ViT-style backbone for Earth Observation built around a Universal Patch Encoder that handles arbitrary spatial, spectral, and temporal resolutions, and any sensor — with a single set of...
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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
🚀 Best part: it's a drop-in backbone. Load pretrained weights in one line via torch.hub, feed whatever sensors you have, read out dense features at any resolution. 🪶
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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
🎛️ Bonus superpower: output resolution is decoupled from input patch size — you choose it at inference time. 🔍 A sub-patch skip connection recovers fine detail: sharper field boundaries, roads & parcel edges, with way less positional collapse than other backbones. ✨
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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
🌈 And it goes where most EO models can't: hyperspectral. On SpectralEarth (EnMAP, up to 500 bands), UniverSat beats DOFA-L across every task & approaches the EnMAP-specialised SpectralEarth-L — despite NEVER seeing EnMAP in training. 🤯
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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
📊 And it's not just flexible — it's competitive. 🔥 Competitive with specialist baselines across GeoBench & PangaeaBench, using both kNN and linear probing 🔥 On PangaeaBench, a 9K-param linear probe matches 33M–47M-param decoders (~4000× fewer params!) 🤯
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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
🔑 The core idea: the Universal Patch Encoder. It takes patches of any spatial/spectral/temporal shape and embeds them in linear time into a shared embedding space, with sequential Axial Cross-Attention and dedicated positional encodings for wavelength, polarization & time.⚡
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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
🤔 The problem: ViTs expects a fixed input format. But EO data formats vary a lot: 🌐 Optical, radar, hyperspectral, elevation 📏 cm → hundreds of m 🌈 1 → 396 spectral bands ⏱️ 1 → 150+ revisits No two satellite images share the same format. UniverSat eats them all. 😋
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Guillaume Astruc @gastruc.bsky.social · 23/06/2026
🛰️ Introducing UniverSat: one transformer backbone for Earth Observation that handles ANY sensor, ANY spatial, spectral & temporal resolution, ANY scale — with a single set of weights. 🌍
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Antoine Guédon @antoine-guedon.bsky.social · 16/06/2026
What if you could turn any number of photos (3, 8, 15, or even 60) into one clean 3D surface (pts & mesh) with Flow Matching? Check out our new work, Surflo: Consistent 3D Surface Flow Model with Global State. 🧵 1/N 🔗https://anttwo.github.io/surflo/
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Guillaume Astruc @gastruc.bsky.social · 16/04/2026
A huge thank you to the amazing team at Google Geo for welcoming me and making this internship such a nice experience! Dive into the paper and code here: 📄 Paper: arxiv.org/pdf/2604.11668 💻 Code: github.com/gastruc/unig... 🌐 Project: gastruc.github.io/unigeoclip
gastruc.github.io
UNIGEOCLIP: Unified Geospatial Contrastive Learning
UNIGEOCLIP aligns text, aerial imagery, street-level views, DSMs, and geographic coordinates in a single unified embedding space via all-to-all contrastive learning.
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Guillaume Astruc @gastruc.bsky.social · 16/04/2026
UniGeoCLIP is a powerful pretext task for backbones. Aligning these modalities builds features that excel at: ✅ Classif/Seg (aerial/DSM) ✅ Zero-shot cross-modal retrieval (generalizes to unseen cities like Amsterdam! 🇳🇱)
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Guillaume Astruc @gastruc.bsky.social · 16/04/2026
GPS embeddings don't just encode location—they learn deep semantics. 🧠 We prove this by predicting health, social & environmental indicators via the GPS encoder alone. PCA reveals dense urban structures (parks, zones) purely from coordinate space.
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Guillaume Astruc @gastruc.bsky.social · 16/04/2026
How do you encode location? We moved beyond standard RFF/SIREN baselines. Our Multi-scale Lat-Long Encoder is specifically scaled to capture everything from local street blocks to regional geography using cross-scale self-attention. It’s the key to our SOTA downstream performance
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Guillaume Astruc @gastruc.bsky.social · 16/04/2026
Most models treat satellite, street-view, and GPS as separate silos. UniGeoCLIP uses an all-to-all contrastive alignment to jointly link: Aerial 🛰️, Street-level 📸, Elevation (DEM) 🏔️, Text 📝, GPS 📍 More modalities = better representations.
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Guillaume Astruc @gastruc.bsky.social · 16/04/2026
Excited to share my work as a Student Researcher at Google Zurich: UniGeoCLIP! 🌍🚀 W/ Eduard Trulls, Jan Hosang, @loicland.bsky.social & @pesarlin.bsky.social , we built a framework aligning 5 geospatial modalities in one space. Presented at EarthVision @ #CVPR2026. 🧵👇
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David Picard @davidpicard.eurosky.social · 08/04/2026
🚨 arxiv.org/abs/2604.06129 PoM: A Linear-Time Replacement for Attention with the Polynomial Mixer This paper is the result of doing a lab-wide hackathon on an idea I've had for some time. Probably the paper with the highest number of authors I've ever done. It's a CVPR Findings 26. Thread 🧵👇
arxiv.org
PoM: A Linear-Time Replacement for Attention with the Polynomial Mixer
This paper introduces the Polynomial Mixer (PoM), a novel token mixing mechanism with linear complexity that serves as a drop-in replacement for self-attention. PoM aggregates input tokens into a comp...
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Nicolas Dufour @nicolasdufour.bsky.social · 31/10/2025
We introduce MIRO: a new paradigm for T2I model alignment integrating reward conditioning into pretraining, eliminating the need for separate fine-tuning/RL stages. This single-stage approach offers unprecedented efficiency and control. - 19x faster convergence ⚡ - 370x less FLOPS than FLUX-dev 📉
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Guillaume Astruc @gastruc.bsky.social · 18/08/2025
Super interesting to see pure SSL outperforms text alignement on a super competitive but text-aligned suited task 🤯
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Guillaume Astruc @gastruc.bsky.social · 11/06/2025
🛰️ At #CVPR2025 presenting "AnySat: An Earth Observation Model for Any Resolutions, Scales, and Modalities" - Saturday afternoon, Poster 355! If you're here and want to discuss geolocation or geospatial foundation models, let's connect!
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Nicolas Gonthier @nicaogr.bsky.social · 11/06/2025
📢 FLAIR-HUB dataset A new large-scale, multimodal dataset for land cover and crop type mapping 🤗 Dataset: huggingface.co/datasets/IGN... 📄 Preprint: arxiv.org/abs/2506.07080 🤗 Pretrained models: huggingface.co/collections/... 💻 Code: github.com/IGNF/FLAIR-HUB 🌐 Project : arxiv.org/abs/2506.07080
arxiv.org
FLAIR-HUB: Large-scale Multimodal Dataset for Land Cover and Crop Mapping
The growing availability of high-quality Earth Observation (EO) data enables accurate global land cover and crop type monitoring. However, the volume and heterogeneity of these datasets pose major pro...
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Elliot Vincent @elliotvincent.github.io · 11/06/2025
I will be presenting our work on the detection of archaeological looting with satellite image time series at CVPR 2025 EarthVision workshop tomorrow! Honored and grateful that this paper received the best student paper award!
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Ryan @ryanboustany.bsky.social · 23/05/2025
📢 New preprint! “When majority rules, minority loses: bias amplification of gradient descent” We often blame biased data but training also amplifies biases. Our paper explores how ML algorithms favor stereotypes at the expense of minority groups. ➡️ arxiv.org/abs/2505.13122 (1/3)
arxiv.org
When majority rules, minority loses: bias amplification of gradient descent
Despite growing empirical evidence of bias amplification in machine learning, its theoretical foundations remain poorly understood. We develop a formal framework for majority-minority learning tasks, ...
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Guillaume Astruc @gastruc.bsky.social · 30/04/2025
We've added new experiments demonstrating robust generalization capabilities! Notably, AnySat shows strong performance on HLS Burn Scars - a sensor never seen during pretraining! 🔥🛰️ Check it out: 📄 Paper: arxiv.org/abs/2412.14123 🌐 Project: gastruc.github.io/anysat
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Imagine-ENPC @imagineenpc.bsky.social · 30/04/2025
Looking forward to #CVPR2025! We will present the following papers:
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Nicolas Gonthier @nicaogr.bsky.social · 28/04/2025
Introducing HySCDG #CVPR2025, a generative pipeline for creating a large hybrid semantic change detection for Earth Observation using Stable Diffusion and ControlNet ! 🗺️🛩️ 📄 Paper: arxiv.org/abs/2503.15683
arxiv.org
The Change You Want To Detect: Semantic Change Detection In Earth Observation With Hybrid Data Generation
Bi-temporal change detection at scale based on Very High Resolution (VHR) images is crucial for Earth monitoring. This remains poorly addressed so far: methods either require large volumes of annotate...
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Antoine Guédon @antoine-guedon.bsky.social · 03/04/2025
💻We've released the code for our #CVPR2025 paper MAtCha! 🍵MAtCha reconstructs sharp, accurate and scalable meshes of both foreground AND background from just a few unposed images (eg 3 to 10 images)... ...While also working with dense-view datasets (hundreds of images)!
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David Picard @davidpicard.eurosky.social · 21/03/2025
🔥🔥🔥 CV Folks, I have some news! We're organizing a 1-day meeting in center Paris on June 6th before CVPR called CVPR@Paris (similar as NeurIPS@Paris) 🥐🍾🥖🍷 Registration is open (it's free) with priority given to authors of accepted papers: cvprinparis.github.io/CVPR2025InPa... Big 🧵👇 with details!
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Imagine-ENPC @imagineenpc.bsky.social · 14/03/2025
Starter pack including some of the lab members: go.bsky.app/QK8j87w
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Thibaut Loiseau @thibautloiseau.bsky.social · 28/02/2025
🧩 Excited to share our paper "RUBIK: A Structured Benchmark for Image Matching across Geometric Challenges" (arxiv.org/abs/2502.19955) accepted to #CVPR2025! We created a benchmark that systematically evaluates image matching methods across well-defined geometric difficulty levels. 🔍
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Nicolas Dufour @nicolasdufour.bsky.social · 20/02/2025
Weights for CAD are finally available. It's one of the smallest diffusion models on the market, achieving performance close to SD and Pixart, featuring a Perceiver-like architecture. We leverage our coherence aware training to improve the textual understanding
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Guillaume Astruc @gastruc.bsky.social · 19/12/2024
🔗 Check it out: 📜 Paper: arxiv.org/abs/2412.14123 🌐 Project: gastruc.github.io/anysat 🤗 HuggingFace: huggingface.co/g-astruc/Any... 🐙 GitHub: github.com/gastruc/AnySat
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Guillaume Astruc @gastruc.bsky.social · 19/12/2024
🚀 Even better: AnySat supports linear probing for semantic segmentation! That means you can fine-tune just a few thousand parameters and achieve SOTA results on challenging tasks—all with minimal effort.
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Guillaume Astruc @gastruc.bsky.social · 19/12/2024
AnySat achieves SOTA performance on 6 tasks across 10 datasets: 🌱 Land cover mapping 🌾 Crop type segmentation 🌳 Tree species classification 🌊 Flood detection 🌍 Change detection
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Guillaume Astruc @gastruc.bsky.social · 19/12/2024
We trained AnySat on 5 multimodal datasets simultaneously: 📡 11 distinct sensors 📏 Resolutions: 0.2m–500m 🔁 Revisit: single date to weekly 🏞️ Scales: 0.3–150 hectares The pretrained model can adapt to truly diverse data, and probably yours too!
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Guillaume Astruc @gastruc.bsky.social · 19/12/2024
🔍Thanks to our modified JEPA training scheme and scale-adaptive spatial encoders, AnySat trains on datasets with diverse scales, resolutions, and modalities! 🧠 75% of its parameters are shared across all inputs, enabling unmatched flexibility.
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Guillaume Astruc @gastruc.bsky.social · 19/12/2024
🤔 What if embedding multimodal EO data was as easy as using a ResNet on images? Introducing AnySat: one model for any resolution (0.2m–250m), scale (0.3–2600 hectares), and modalities (choose from 11 sensors & time series)! Try it with just a few lines of code:
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arxiv cs.CV @arxiv-cs-cv.bsky.social · 19/12/2024
Guillaume Astruc, Nicolas Gonthier, Clement Mallet, Loic Landrieu AnySat: An Earth Observation Model for Any Resolutions, Scales, and Modalities arxiv.org/abs/2412.14123
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Antoine Guédon @antoine-guedon.bsky.social · 11/12/2024
⚠️Reconstructing sharp 3D meshes from a few unposed images is a hard and ambiguous problem. ☑️With MAtCha, we leverage a pretrained depth model to recover sharp meshes from sparse views including both foreground and background, within mins!🧵 🌐Webpage: anttwo.github.io/matcha/
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Nicolas Dufour @nicolasdufour.bsky.social · 10/12/2024
🌍 Guessing where an image was taken is a hard, and often ambiguous problem. Introducing diffusion-based geolocation—we predict global locations by refining random guesses into trajectories across the Earth's surface! 🗺️ Paper, code, and demo: nicolas-dufour.github.io/plonk
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Guillaume Astruc @gastruc.bsky.social · 25/11/2024
Hi, I am a PhD student from @imagineenpc.bsky.social. Could you also add us both please?
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