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Nicolas Ballas

32 accepted papers

2026

Inference-time Physics Alignment of Video Generative Models with Latent World Models

CVPR 2026

State-of-the-art video generative models produce promising visual content yet often violate basic physics principles, limiting their utility. While some attribute this deficiency to insufficient physics understanding from pre-training, we find that the shortfall in physics plausibility also stems fr

Cited by 0SourcecodeScholar
2026

Learning Latent Action World Models In The Wild

ICML 2026poster

Agents that can reason and plan in the real world must be able to predict the consequences of their actions. World models possess this capability but require action annotations that can be complex to obtain at scale. Latent action models address this issue by learning an action space from videos alo…

Cited by 0SourceScholar
2026

Towards Unified Multimodal Pretraining

ICML 2026spotlight

Unified multimodal models aim to input and output both vision and language data within a single system. In this work, we explore the design space of Unified Multimodal Pretraining through a controlled, from-scratch study. We find that leveraging a single high-dimensional semantic encoder (e.g. SigLI…

Cited by 0SourceScholar
2025

LOCATE 3D: Real-World Object Localization via Self-Supervised Learning in 3D

ICML 2025spotlight

We present LOCATE 3D, a model for localizing objects in 3D scenes from referring expressions like "the small coffee table between the sofa and the lamp." LOCATE 3D sets a new state-of-the-art on standard referential grounding benchmarks and showcases robust generalization capabilities. Notably, LOCA…

Cited by 0SourcePDFScholar
2025

Scaling Language-Free Visual Representation Learning

ICCV 2025poster

Visual Self-Supervised Learning (SSL) currently underperforms Contrastive Language-Image Pretraining (CLIP) in multimodal settings such as Visual Question Answering (VQA). This multimodal gap is often attributed to the semantics introduced by language supervision, even though visual SSL and CLIP mod…

2025

VEDIT: Latent Prediction Architecture For Procedural Video Representation Learning

ICLR 2025poster

Procedural video representation learning is an active research area where the objective is to learn an agent which can anticipate and forecast the future given the present video input, typically in conjunction with textual annotations. Prior works often rely on large-scale pretraining of visual enco…

Cited by 1SourcePDFScholar
2024

Discovering Environments with XRM

ICML 2024oral

Environment annotations are essential for the success of many out-of-distribution (OOD) generalization methods. Unfortunately, these are costly to obtain and often limited by human annotators' biases. To achieve robust generalization, it is essential to develop algorithms for automatic environment d…

2024

Jack of All Tasks Master of Many: Designing General-Purpose Coarse-to-Fine Vision-Language Model

CVPR 2024highlight

The ability of large language models (LLMs) to process visual inputs has given rise to general-purpose vision systems unifying various vision-language (VL) tasks by instruction tuning. However due to the enormous diversity in input-output formats in the vision domain existing general-purpose models…

2024

Modeling Caption Diversity in Contrastive Vision-Language Pretraining

ICML 2024poster

There are a thousand ways to caption an image. Contrastive Language Pretraining (CLIP) on the other hand, works by mapping an image and its caption to a single vector -- limiting how well CLIP-like models can represent the diverse ways to describe an image. In this work, we introduce Llip, Latent La…

2024

Stochastic positional embeddings improve masked image modeling

ICML 2024poster

Masked Image Modeling (MIM) is a promising self-supervised learning approach that enables learning from unlabeled images. Despite its recent success, learning good representations through MIM remains challenging because it requires predicting the right semantic content in accurate locations. For exa…

2023

ImageNet-X: Understanding Model Mistakes with Factor of Variation Annotations

ICLR 2023top-25%

Deep learning vision systems are widely deployed across applications where reliability is critical. However, even today's best models can fail to recognize an object when its pose, lighting, or background varies. While existing benchmarks surface examples challenging for models, they do not explain…

Cited by 50SourcePDFScholar
2023

Self-Supervised Learning From Images With a Joint-Embedding Predictive Architecture

CVPR 2023poster

This paper demonstrates an approach for learning highly semantic image representations without relying on hand-crafted data-augmentations. We introduce the Image-based Joint-Embedding Predictive Architecture (I-JEPA), a non-generative approach for self-supervised learning from images. The idea behin…

2023

The hidden uniform cluster prior in self-supervised learning

ICLR 2023poster

A successful paradigm in representation learning is to perform self-supervised pretraining using tasks based on mini-batch statistics; (e.g., SimCLR, VICReg, SwAV, MSN). We show that in the formulation of all these methods is an overlooked prior to learn features that enable uniform clustering of th…

Cited by 60SourcePDFScholar
2022

Masked Siamese Networks for Label-Efficient Learning

ECCV 2022poster

"We propose Masked Siamese Networks (MSN), a self-supervised learning framework for learning image representations. Our approach matches the representation of an image view containing randomly masked patches to the representation of the original unmasked image. This self-supervised pre-training stra…

2022

Neural Attentive Circuits

NeurIPS 2022accept

Recent work has seen the development of general purpose neural architectures that can be trained to perform tasks across diverse data modalities. General purpose models typically make few assumptions about the underlying data-structure and are known to perform well in the large-data regime. At the s…

Cited by 6SourcePDFScholar
2021

Semi-Supervised Learning of Visual Features by Non-Parametrically Predicting View Assignments With Support Samples

ICCV 2021poster

This paper proposes a novel method of learning by predicting view assignments with support samples (PAWS). The method trains a model to minimize a consistency loss, which ensures that different views of the same unlabeled instance are assigned similar pseudo-labels. The pseudo-labels are generated n…

Cited by 191PDFcodeScholar
2020

Lookahead Converges to Stationary Points of Smooth Non-convex Functions

ICASSP 2020accepted

The Lookahead optimizer [Zhang et al., 2019] was recently proposed and demonstrated to improve performance of stochastic first-order methods for training deep neural networks. Lookahead can be viewed as a two time-scale algorithm, where the fast dynamics (inner optimizer) determine a search directio…

Cited by 0SourceScholar
2020

SlowMo: Improving Communication-Efficient Distributed SGD with Slow Momentum

ICLR 2020poster

Distributed optimization is essential for training large models on large datasets. Multiple approaches have been proposed to reduce the communication overhead in distributed training, such as synchronizing only after performing multiple local SGD steps, and decentralized methods (e.g., using gossip…

Cited by 217SourcecodeScholar
2019

Gossip-based Actor-Learner Architectures for Deep Reinforcement Learning

NeurIPS 2019poster

Multi-simulator training has contributed to the recent success of Deep Reinforcement Learning (Deep RL) by stabilizing learning and allowing for higher training throughputs. In this work, we propose Gossip-based Actor-Learner Architectures (GALA) where several actor-learners (such as A2C agents) are…

2019

On the Relation Between the Sharpest Directions of DNN Loss and the SGD Step Length

ICLR 2019poster

The training of deep neural networks with Stochastic Gradient Descent (SGD) with a large learning rate or a small batch-size typically ends in flat regions of the weight space, as indicated by small eigenvalues of the Hessian of the training loss. This was found to correlate with a good final genera…

2019

Stochastic Gradient Push for Distributed Deep Learning

ICML 2019oral

Distributed data-parallel algorithms aim to accelerate the training of deep neural networks by parallelizing the computation of large mini-batch gradient updates across multiple nodes. Approaches that synchronize nodes using exact distributed averaging (e.g., via AllReduce) are sensitive to straggle…

2018

Fast Approximate Natural Gradient Descent in a Kronecker Factored Eigenbasis

NeurIPS 2018poster

Optimization algorithms that leverage gradient covariance information, such as variants of natural gradient descent (Amari, 1998), offer the prospect of yielding more effective descent directions. For models with many parameters, the covari- ance matrix they are based on becomes gigantic, making the…

Cited by 193SourcePDFScholar
2018

Residual Connections Encourage Iterative Inference

ICLR 2018poster

Residual networks (Resnets) have become a prominent architecture in deep learning. However, a comprehensive understanding of Resnets is still a topic of ongoing research. A recent view argues that Resnets perform iterative refinement of features. We attempt to further expose properties of this aspec…

Cited by 174SourcePDFScholar
2017

A Closer Look at Memorization in Deep Networks

ICML 2017poster

We examine the role of memorization in deep learning, drawing connections to capacity, generalization, and adversarial robustness. While deep networks are capable of memorizing noise data, our results suggest that they tend to prioritize learning simple patterns first. In our experiments, we expose…

Cited by 2324SourcePDFScholar
2017

A Dataset and Exploration of Models for Understanding Video Data Through Fill-In-The-Blank Question-Answering

CVPR 2017poster

While deep convolutional neural networks frequently approach or exceed human-level performance in benchmark tasks involving static images, extending this success to moving images is not straightforward. Video understanding is of interest for many applications, including content recommendation, predi…

Cited by 126PDFcodeScholar
2017

Zoneout: Regularizing RNNs by Randomly Preserving Hidden Activations

ICLR 2017poster

We propose zoneout, a novel method for regularizing RNNs. At each timestep, zoneout stochastically forces some hidden units to maintain their previous values. Like dropout, zoneout uses random noise to train a pseudo-ensemble, improving generalization. But by preserving instead of dropping hidden un…

Cited by 397SourcecodeScholar
2016

Dynamic Capacity Networks

ICML 2016poster

We introduce the Dynamic Capacity Network (DCN), a neural network that can adaptively assign its capacity across different portions of the input data. This is achieved by combining modules of two types: low-capacity sub-networks and high-capacity sub-networks. The low-capacity sub-networks are appli…

Cited by 160SourcePDFScholar
2015

Describing Videos by Exploiting Temporal Structure

ICCV 2015poster

Recent progress in using recurrent neural networks (RNNs) for image description has motivated the exploration of their application for video description. However, while images are static, working with videos requires modeling their dynamic temporal structure and then properly integrating that inform…

Cited by 1392PDFcodeScholar