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René Vidal

14 accepted papers

2026

Dictionary-Aligned Concept Control for Safeguarding Multimodal LLMs

CVPR 2026

Multimodal Large Language Models (MLLMs) have been shown to be vulnerable to malicious queries that can elicit unsafe responses. Recent work uses prompt engineering, response classification, or finetuning to improve MLLM safety. Nevertheless, such approaches are often ineffective against evolving ma

Cited by 0SourcecodeScholar
2026

ImageRAGTurbo: Towards One-step Text-to-Image Generation with Retrieval-Augmented Diffusion Models

CVPR 2026

Diffusion models have emerged as the leading approach for text-to-image generation. However, their iterative sampling process, which gradually morphs random noise into coherent images, introduces significant latency that limits their applicability. While recent few-step diffusion models reduce the n

Cited by 0SourceScholar
2025

Learning Interpretable Queries for Explainable Image Classification with Information Pursuit

ICCV 2025poster

Information Pursuit (IP) is a recently introduced learning framework to construct classifiers that are interpretable-by-design. Given a set of task-relevant and interpretable data queries, IP selects a small subset of the most informative queries and makes predictions based on the gathered query-ans…

Cited by 0SourcePDFScholar
2023

On the Convergence of IRLS and Its Variants in Outlier-Robust Estimation

CVPR 2023highlight

Outlier-robust estimation involves estimating some parameters (e.g., 3D rotations) from data samples in the presence of outliers, and is typically formulated as a non-convex and non-smooth problem. For this problem, the classical method called iteratively reweighted least-squares (IRLS) and its vari…

2022

Semidefinite Relaxations of Truncated Least-Squares in Robust Rotation Search: Tight or Not

ECCV 2022poster

"The rotation search problem aims to find a 3D rotation that best aligns a given number of point pairs. To induce robustness against outliers for rotation search, prior work considers truncated least-squares (TLS), which is a non-convex optimization problem, and its semidefinite relaxation (SDR) as…

Cited by 7SourcePDFScholar
2022

Weakly-Supervised Generation and Grounding of Visual Descriptions With Conditional Generative Models

CVPR 2022poster

Given weak supervision from image- or video-caption pairs, we address the problem of grounding (localizing) each object word of a ground-truth or generated sentence describing a visual input. Recent weakly-supervised approaches leverage region proposals and ground words based on the region attention…

Cited by 10PDFScholar
2020

Representation Learning on Visual-Symbolic Graphs for Video Understanding

ECCV 2020poster

Events in natural videos typically arise from spatio-temporal interactions between actors and objects and involve multiple co-occurring activities and object classes. To capture this rich visual and semantic context, we propose using two graphs:(1) an attributed spatio-temporal visual graph whose no…

Cited by 44SourcePDFScholar
2019

A Linearly Convergent Method for Non-Smooth Non-Convex Optimization on the Grassmannian with Applications to Robust Subspace and Dictionary Learning

NeurIPS 2019poster

Minimizing a non-smooth function over the Grassmannian appears in many applications in machine learning. In this paper we show that if the objective satisfies a certain Riemannian regularity condition with respect to some point in the Grassmannian, then a Riemannian subgradient method with appropri…

Cited by 30SourcePDFScholar
2018

Dual Principal Component Pursuit: Improved Analysis and Efficient Algorithms

NeurIPS 2018poster

Recent methods for learning a linear subspace from data corrupted by outliers are based on convex L1 and nuclear norm optimization and require the dimension of the subspace and the number of outliers to be sufficiently small [27]. In sharp contrast, the recently proposed Dual Principal Component Pur…

Cited by 61SourcePDFScholar
2018

Multi-Cell Detection and Classification Using a Generative Convolutional Model

CVPR 2018poster

Detecting, counting, and classifying various cell types in images of human blood is important in many biomedical applications. However, these tasks can be very difficult due to the wide range of biological variability and the resolution limitations of many imaging modalities. This paper proposes a…

Cited by 9SourcePDFScholar