Projects

Fine-tuning representation shift diagram

Analyzing Fine-tuning Representation Shift for Multimodal LLMs Steering alignment

Pegah Khayatan, Mustafa Shukor, Jayneel Parekh, Arnaud Dapogny, Matthieu Cord · ICCV 2025

We systematically analyze the evolution of hidden state representations to reveal how fine-tuning alters the internal structure of a model to specialize in new multimodal tasks. Using concept-based shift vectors, we can recover fine-tuned concepts and steer model behaviors without any training.

Concept-based explainability framework diagram

A Concept-Based Explainability Framework for Large Multimodal Models

Jayneel Parekh, Pegah Khayatan, Mustafa Shukor, Alasdair Newson, Matthieu Cord · NeurIPS 2024

A novel framework for interpreting large multimodal models using dictionary learning applied to token representations. The learned dictionary elements correspond to well-grounded multimodal concepts, evaluated for disentanglement and visual-textual grounding quality.

ReGentS scenario generation diagram

ReGentS: Real-World Safety-Critical Driving Scenario Generation Made Stable

Yuan Yin, Pegah Khayatan, Éloi Zablocki, Alexandre Boulch, Matthieu Cord · ECCV Workshop 2024

A framework for generating safety-critical driving scenarios by modifying real-world regular scenarios through trajectory optimization. ReGentS stabilizes generated trajectories and introduces heuristics to avoid unrealistic diverging paths and unavoidable collisions, scaling to up to 32 agents via a differentiable simulator.

Adversarial driving scenario

Adversarial Corner Case Generation for Motion Planning

A framework to stress-test vehicle planners by generating safety-critical driving scenarios using the nuPlan simulator, exposing potential collision risks.

Velocity skinning animation demo

Simplified Velocity Skinning

Pegah Khayatan

A course project making animations more realistic by adding exaggerated deformation triggered by skeletal velocity on top of standard skinning. Built using a CGP library and based on a simplification of the Velocity Skinning paper.

Clothing landmark detection demo

Landmark Localization for a Fashion Dataset: A PIFPAF Plugin

Pegah Khayatan

An OpenPifPaf plugin for detecting key landmarks — such as sleeve ends in shirts — across various clothing items in a fashion dataset.