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François-Guillaume Fernandez · Paris

I teach cameras to see.

I'm F-G, a computer vision researcher turned founder. From food at Foodvisor and documents at Mindee to wildfire at Pyronear and now intrusion detection at Rimward, I keep coming back to the same obsession: making images useful.

Five questions, one grid

Chapter by chapter: the real 7 by 7 class activation map TorchCAM computed for a photo of a dog; an illustrated plate labelled on finer and finer grids, then estimated in calories; an illustrated invoice whose due date is found among three dates and normalised; real frames from a Pyronear camera, the first labelled plume smaller than a 32-pixel cell, the same smoke traced ninety seconds later, then an illustrated fix from two cameras' bearings; and an illustrated perimeter over four night-vision frames, where a person crosses the fence, then the site map with the camera and the entry point.input3 × 224 × 224conv164 × 112 × 112layer164 × 56 × 56layer2128 × 28 × 28layer3256 × 14 × 14layer4512 × 7 × 7stride: 32 pxCAM · 7 × 7lowhigh1 label7 × 714 × 1428 × 2856 × 56one label per celltomato6 slicesmozzarella6 slicesolive3 olivesbasil5 leaves3 dates on the page30/09/2026issued03/10/2026delivered30/10/2026duedue_date30/-10/-2026read as 30/10/2026normalised to ISO 8601Ateliers VaucansonMenuiserie · serrurerie14 quai Saint-Vincent, 69001 LyonFACTUREN° 2026-117Facturé àMaison Daguerre8 rue des Lumières75003 ParisDate de factureDate de livraisonÉchéance30/09/202603/10/202630/10/2026DésignationQtéPU HTTotal HTSupport caméra galvanisé438,00152,00Boîtier étanche IP66264,50129,00Pose, demi-journée1240,00240,00Total HT521,00TVA 20 %104,20Total TTC625,20 €Paiement à 30 jours par virement.Merci de rappeler le numéro de facture.one cell: 32 pxfirst label, 08:30:5423 × 29 pxnow−1 s−2 s−3 sperson · crossing

01 · Interpretability

Why does it say “dog”?

TorchCAM scores every cell of the network's last grid to show what drove the prediction: here, the head and chest. It started as a project to better understand and implement research papers on computer vision explainability.

Photo: Woopets.

02 · Food recognition

What's on the plate?

Foodvisor turns a meal photo into nutrition tracking: each food is found region by region, then becomes a portion with its calories.

03 · Document understanding

When is it due?

Three dates on the page, one due. Reading an invoice means finding the text, decoding every character and knowing which field it belongs to.

04 · Small-object detection

Where's the fire?

The earliest smoke is the smallest: here, 23 × 29 pixels, less than one 32-pixel cell. Spotting it is half the job; firefighters also need its GPS position, from the bearings of two cameras.

Frames and labels: Pyro-SDIS, Pyronear's open dataset (camera cabanelle-125, 24 Feb 2024).

05 · Video & intent

Who goes there?

One frame shows a person; a few seconds show intent. Rimward detects someone entering a protected site and says where: which site, which camera, which stretch of fence.

Selected work

Rimward ↗

Founder · YC S23 · 2023—

Many cameras, one replay

123N50 m123entry 02:141 alert

Existing CCTV · where, when, what to do

Intrusion detection for solar plants.

It started with a question about copper theft.

A site we were protecting against wildfire with Pyronear asked whether we could help with copper theft. That request became Rimward. I founded it and built the product end to end.

Pyronear ↗

Initiator & co-founder · 2019—

Smoke, 30+ km away

0102030 km

4–5 cameras per station · detection on site

Wildfire detection people can afford to deploy.

I pitched the idea to a volunteer association and built the first vision models and backend API. To find training data from the field, we collected imagery from US national-park cameras rather than Google Images. We chose affordable cameras and straightforward deployment over satellite imagery.

The wider team now develops the vision algorithms. The network has reached France, Chile, Spain and beyond; in summer 2026, a camera detected a wildfire more than 30 km away.

TorchCAM ↗

Creator · Research & open source · 2020—

12 explainability methods

boat96%boat97%looks at the boatlooks at the water

pip install torchcam

Research papers. A small codebase. An API I wanted to use.

I built TorchCAM on my own as a researcher to look for visual bias in the models I trained. The existing tooling wasn't the interface I wanted, so I implemented the research papers behind class activation maps in a small library with a clean PyTorch API.

It has since found its way into research, including COVID-19 chest X-ray studies. The published demo shows a real class activation map.

Writing

All writing →

On science, technology and creativity.

Frontend finally clicked: a Python-first mental model

2025-10-25

Speaking

Detect forest wildfires using AI ↗

Datagen podcast

2023-02-27

Early detection of wildfires ↗

DataXDay 2021

2021-06-24

Beyond the projects

Books, films, tools, and the things I keep coming back to.

A look at my desk →