selected research (all)

I’m interested in self-supervised learning, representation learning, curiosity-based exploration, and leveraging internet-scale models and data. I am keen to draw inspiration from intelligence in humans and nature—especially as a goal-post rather than a blueprint. My long-term goal is to develop intelligent agents that can generalize and continually adapt as robustly and efficiently as humans do, allowing them to be safely deployed in the real world.

publications

2024

1. 

   Cambrian-1: A Fully Open, Vision-Centric Exploration of Multimodal LLMs

   Shengbang Tong* ,  Ellis Brown* ,  Penghao Wu* ,  Sanghyun Woo ,  Manoj Middepogu ,  Sai Charitha Akula ,  Jihan Yang ,  Shusheng Yang ,  Adithya Iyer ,  Xichen Pan ,  Austin Wang ,  Rob Fergus ,  Yann LeCun ,  and  Saining Xie

   In NeurIPS , 2024

   🎖️ Oral Presentation (1.8%)

   Abs arXiv Bib PDF Code Website

   We introduce Cambrian-1, a family of multimodal LLMs (MLLMs) designed with a vision-centric approach. While stronger language models can enhance multimodal capabilities, the design choices for vision components are often insufficiently explored and disconnected from visual representation learning research. This gap hinders accurate sensory grounding in real-world scenarios. Our study uses LLMs and visual instruction tuning as an interface to evaluate various visual representations, offering new insights into different models and architectures—self-supervised, strongly supervised, or combinations thereof—based on experiments with over 20 vision encoders. We critically examine existing MLLM benchmarks, addressing the difficulties involved in consolidating and interpreting results from various tasks, and introduce a new vision-centric benchmark, CV-Bench. To further improve visual grounding, we propose the Spatial Vision Aggregator (SVA), a dynamic and spatially-aware connector that integrates high-resolution vision features with LLMs while reducing the number of tokens. Additionally, we discuss the curation of high-quality visual instruction-tuning data from publicly available sources, emphasizing the importance of data source balancing and distribution ratio. Collectively, Cambrian-1 not only achieves state-of-the-art performance but also serves as a comprehensive, open cookbook for instruction-tuned MLLMs. We provide model weights, code, supporting tools, datasets, and detailed instruction-tuning and evaluation recipes. We hope our release will inspire and accelerate advancements in multimodal systems and visual representation learning.

   @inproceedings{tong2024cambrian,
     title = {{Cambrian-1: A Fully Open, Vision-Centric Exploration of Multimodal LLMs}},
     author = {Tong*, Shengbang and Brown*, Ellis and Wu*, Penghao and Woo, Sanghyun and Middepogu, Manoj and Akula, Sai Charitha and Yang, Jihan and Yang, Shusheng and Iyer, Adithya and Pan, Xichen and Wang, Austin and Fergus, Rob and LeCun, Yann and Xie, Saining},
     year = {2024},
     booktitle = {NeurIPS},
     award = {Oral Presentation (1.8%)}
   }

2. 

   V-IRL: Grounding Virtual Intelligence in Real Life

   Jihan Yang ,  Runyu Ding ,  Ellis Brown ,  Xiaojuan Qi ,  and  Saining Xie

   In ECCV , 2024

   Abs arXiv Bib PDF Code Website

   There is a sensory gulf between the Earth that humans inhabit and the digital realms in which modern AI agents are created. To develop AI agents that can sense, think, and act as flexibly as humans in real-world settings, it is imperative to bridge the realism gap between the digital and physical worlds. How can we embody agents in an environment as rich and diverse as the one we inhabit, without the constraints imposed by real hardware and control? Towards this end, we introduce V-IRL: a platform that enables agents to scalably interact with the real world in a virtual yet realistic environment. Our platform serves as a playground for developing agents that can accomplish various practical tasks and as a vast testbed for measuring progress in capabilities spanning perception, decision-making, and interaction with real-world data across the entire globe.

   @inproceedings{yang2024virl,
     author = {Yang, Jihan and Ding, Runyu and Brown, Ellis and Qi, Xiaojuan and Xie, Saining},
     title = {V-IRL: Grounding Virtual Intelligence in Real Life},
     year = {2024},
     booktitle = {ECCV}
   }

2023

1. 

   Your Diffusion Model is Secretly a Zero-Shot Classifier

   Alexander C. Li ,  Mihir Prabhudesai ,  Shivam Duggal ,  Ellis Brown ,  and  Deepak Pathak

   In ICCV , 2023

   Abs arXiv Bib PDF Website

   The recent wave of large-scale text-to-image diffusion models has dramatically increased our text-based image generation abilities. These models can generate realistic images for a staggering variety of prompts and exhibit impressive compositional generalization abilities. Almost all use cases thus far have solely focused on sampling; however, diffusion models can also provide conditional density estimates, which are useful for tasks beyond image generation.
   
   In this paper, we show that the density estimates from large-scale text-to-image diffusion models like Stable Diffusion can be leveraged to perform zero-shot classification without any additional training. Our generative approach to classification, which we call Diffusion Classifier, attains strong results on a variety of benchmarks and outperforms alternative methods of extracting knowledge from diffusion models. Although a gap remains between generative and discriminative approaches on zero-shot recognition tasks, our diffusion-based approach has significantly stronger multimodal compositional reasoning ability than competing discriminative approaches.
   
   Finally, we use Diffusion Classifier to extract standard classifiers from class-conditional diffusion models trained on ImageNet. Our models achieve strong classification performance using only weak augmentations and exhibit qualitatively better "effective robustness" to distribution shift. Overall, our results are a step toward using generative over discriminative models for downstream tasks.

   @inproceedings{li2023diffusion,
     title = {Your Diffusion Model is Secretly a Zero-Shot Classifier},
     author = {Li, Alexander C. and Prabhudesai, Mihir and Duggal, Shivam and Brown, Ellis and Pathak, Deepak},
     year = {2023},
     booktitle = {ICCV},
     pages = {2206-2217},
   }

2. 

   Internet Explorer: Targeted Representation Learning on the Open Web

   Alexander C. Li* ,  Ellis Brown* ,  Alexei A. Efros ,  and  Deepak Pathak

   In ICML , 2023

   Abs arXiv Bib PDF Website

   Vision models heavily rely on fine-tuning general-purpose models pre-trained on large, static datasets. These general-purpose models only understand knowledge within their pre-training datasets, which are tiny, out-of-date snapshots of the Internet—where billions of images are uploaded each day. We suggest an alternate approach: rather than hoping our static datasets transfer to our desired tasks after large-scale pre-training, we propose dynamically utilizing the Internet to quickly train a small-scale model that does extremely well on the task at hand. Our approach, called Internet Explorer, explores the web in a self-supervised manner to progressively find relevant examples that improve performance on a desired target dataset. It cycles between searching for images on the Internet with text queries, self-supervised training on downloaded images, determining which images were useful, and prioritizing what to search for next. We evaluate Internet Explorer across several datasets and show that it outperforms or matches CLIP oracle performance by using just a single GPU desktop to actively query the Internet for 30–40 hours.

   @inproceedings{li2023internet,
     title = {Internet Explorer: Targeted Representation Learning on the Open Web},
     author = {Li*, Alexander C. and Brown*, Ellis and Efros, Alexei A. and Pathak, Deepak},
     year = {2023},
     booktitle = {ICML},
   }

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