Jonathan Huang

ICLR Conference 2025 Conference Paper

Representation Alignment for Generation: Training Diffusion Transformers Is Easier Than You Think

• Sihyun Yu
• Sangkyung Kwak
• Huiwon Jang
• Jongheon Jeong
• Jonathan Huang
• Jinwoo Shin
• Saining Xie

Recent studies have shown that the denoising process in (generative) diffusion models can induce meaningful (discriminative) representations inside the model, though the quality of these representations still lags behind those learned through recent self-supervised learning methods. We argue that one main bottleneck in training large-scale diffusion models for generation lies in effectively learning these representations. Moreover, training can be made easier by incorporating high-quality external visual representations, rather than relying solely on the diffusion models to learn them independently. We study this by introducing a straightforward regularization called REPresentation Alignment (REPA), which aligns the projections of noisy input hidden states in denoising networks with clean image representations obtained from external, pretrained visual encoders. The results are striking: our simple strategy yields significant improvements in both training efficiency and generation quality when applied to popular diffusion and flow-based transformers, such as DiTs and SiTs. For instance, our method can speed up SiT training by over 17.5$\times$, matching the performance (without classifier-free guidance) of a SiT-XL model trained for 7M steps in less than 400K steps. In terms of final generation quality, our approach achieves state-of-the-art results of FID=1.42 using classifier-free guidance with the guidance interval.

ICLR Conference 2025 Conference Paper

Visually Consistent Hierarchical Image Classification

• Seulki Park
• Youren Zhang
• Stella X. Yu
• Sara Beery
• Jonathan Huang

Hierarchical classification predicts labels across multiple levels of a taxonomy, e.g., from coarse-level \textit{Bird} to mid-level \textit{Hummingbird} to fine-level \textit{Green hermit}, allowing flexible recognition under varying visual conditions. It is commonly framed as multiple single-level tasks, but each level may rely on different visual cues. Distinguishing \textit{Bird} from \textit{Plant} relies on {\it global features} like {\it feathers} or {\it leaves}, while separating \textit{Anna's hummingbird} from \textit{Green hermit} requires {\it local details} such as {\it head coloration}. Prior methods improve accuracy using external semantic supervision, but such statistical learning criteria fail to ensure consistent visual grounding at test time, resulting in incorrect hierarchical classification. We propose, for the first time, to enforce \textit{internal visual consistency} by aligning fine-to-coarse predictions through intra-image segmentation. Our method outperforms zero-shot CLIP and state-of-the-art baselines on hierarchical classification benchmarks, achieving both higher accuracy and more consistent predictions. It also improves internal image segmentation without requiring pixel-level annotations.

ICML Conference 2024 Conference Paper

VideoPoet: A Large Language Model for Zero-Shot Video Generation

• Dan Kondratyuk
• Lijun Yu
• Xiuye Gu
• José Lezama
• Jonathan Huang
• Grant Schindler
• Rachel Hornung
• Vighnesh Birodkar

We present VideoPoet, a language model capable of synthesizing high-quality video from a large variety of conditioning signals. VideoPoet employs a decoder-only transformer architecture that processes multimodal inputs – including images, videos, text, and audio. The training protocol follows that of Large Language Models (LLMs), consisting of two stages: pretraining and task-specific adaptation. During pretraining, VideoPoet incorporates a mixture of multimodal generative objectives within an autoregressive Transformer framework. The pretrained LLM serves as a foundation that can be adapted for a range of video generation tasks. We present empirical results demonstrating the model’s state-of-the-art capabilities in zero-shot video generation, specifically highlighting the ability to generate high-fidelity motions. Project page: http: //sites. research. google/videopoet/

NeurIPS Conference 2023 Conference Paper

DaTaSeg: Taming a Universal Multi-Dataset Multi-Task Segmentation Model

• Xiuye Gu
• Yin Cui
• Jonathan Huang
• Abdullah Rashwan
• Xuan Yang
• Xingyi Zhou
• Golnaz Ghiasi
• Weicheng Kuo

Observing the close relationship among panoptic, semantic and instance segmentation tasks, we propose to train a universal multi-dataset multi-task segmentation model: DaTaSeg. We use a shared representation (mask proposals with class predictions) for all tasks. To tackle task discrepancy, we adopt different merge operations and post-processing for different tasks. We also leverage weak-supervision, allowing our segmentation model to benefit from cheaper bounding box annotations. To share knowledge across datasets, we use text embeddings from the same semantic embedding space as classifiers and share all network parameters among datasets. We train DaTaSeg on ADE semantic, COCO panoptic, and Objects365 detection datasets. DaTaSeg improves performance on all datasets, especially small-scale datasets, achieving 54. 0 mIoU on ADE semantic and 53. 5 PQ on COCO panoptic. DaTaSeg also enables weakly-supervised knowledge transfer on ADE panoptic and Objects365 instance segmentation. Experiments show DaTaSeg scales with the number of training datasets and enables open-vocabulary segmentation through direct transfer. In addition, we annotate an Objects365 instance segmentation set of 1, 000 images and release it as a public evaluation benchmark on https: //laoreja. github. io/dataseg.

NeurIPS Conference 2015 Conference Paper

Deep Knowledge Tracing

• Chris Piech
• Jonathan Bassen
• Jonathan Huang
• Surya Ganguli
• Mehran Sahami
• Leonidas Guibas
• Jascha Sohl-Dickstein

Knowledge tracing, where a machine models the knowledge of a student as they interact with coursework, is an established and significantly unsolved problem in computer supported education. In this paper we explore the benefit of using recurrent neural networks to model student learning. This family of models have important advantages over current state of the art methods in that they do not require the explicit encoding of human domain knowledge, and have a far more flexible functional form which can capture substantially more complex student interactions. We show that these neural networks outperform the current state of the art in prediction on real student data, while allowing straightforward interpretation and discovery of structure in the curriculum. These results suggest a promising new line of research for knowledge tracing.

ICML Conference 2015 Conference Paper

Learning Program Embeddings to Propagate Feedback on Student Code

• Chris Piech
• Jonathan Huang
• Andy Nguyen
• Mike Phulsuksombati
• Mehran Sahami
• Leonidas J. Guibas

Providing feedback, both assessing final work and giving hints to stuck students, is difficult for open-ended assignments in massive online classes which can range from thousands to millions of students. We introduce a neural network method to encode programs as a linear mapping from an embedded precondition space to an embedded postcondition space and propose an algorithm for feedback at scale using these linear maps as features. We apply our algorithm to assessments from the Code. org Hour of Code and Stanford University’s CS1 course, where we propagate human comments on student assignments to orders of magnitude more submissions.

NeurIPS Conference 2012 Conference Paper

Probabilistic Event Cascades for Alzheimer's disease

• Jonathan Huang
• Daniel Alexander

Accurate and detailed models of the progression of neurodegenerative diseases such as Alzheimer's (AD) are crucially important for reliable early diagnosis and the determination and deployment of effective treatments. In this paper, we introduce the ALPACA (Alzheimer's disease Probabilistic Cascades) model, a generative model linking latent Alzheimer's progression dynamics to observable biomarker data. In contrast with previous works which model disease progression as a fixed ordering of events, we explicitly model the variability over such orderings among patients which is more realistic, particularly for highly detailed disease progression models. We describe efficient learning algorithms for ALPACA and discuss promising experimental results on a real cohort of Alzheimer's patients from the Alzheimer's Disease Neuroimaging Initiative.

UAI Conference 2011 Conference Paper

Efficient Probabilistic Inference with Partial Ranking Queries

• Jonathan Huang
• Ashish Kapoor
• Carlos Guestrin

Distributions over rankings are used to model data in various settings such as preference analysis and political elections. The factorial size of the space of rankings, however, typically forces one to make structural assumptions, such as smoothness, sparsity, or probabilistic independence about these underlying distributions. We approach the modeling problem from the computational principle that one should make structural assumptions which allow for efficient calculation of typical probabilistic queries. For ranking models, "typical" queries predominantly take the form of partial ranking queries (e.g., given a user's top-k favorite movies, what are his preferences over remaining movies?). In this paper, we argue that riffled independence factorizations proposed in recent literature [7, 8] are a natural structural assumption for ranking distributions, allowing for particularly efficient processing of partial ranking queries.

ICML Conference 2010 Conference Paper

Learning Hierarchical Riffle Independent Groupings from Rankings

• Jonathan Huang
• Carlos Guestrin

JMLR Journal 2009 Journal Article

Fourier Theoretic Probabilistic Inference over Permutations

• Jonathan Huang
• Carlos Guestrin
• Leonidas Guibas

Permutations are ubiquitous in many real-world problems, such as voting, ranking, and data association. Representing uncertainty over permutations is challenging, since there are n! possibilities, and typical compact and factorized probability distribution representations, such as graphical models, cannot capture the mutual exclusivity constraints associated with permutations. In this paper, we use the "low-frequency" terms of a Fourier decomposition to represent distributions over permutations compactly. We present Kronecker conditioning, a novel approach for maintaining and updating these distributions directly in the Fourier domain, allowing for polynomial time bandlimited approximations. Low order Fourier-based approximations, however, may lead to functions that do not correspond to valid distributions. To address this problem, we present a quadratic program defined directly in the Fourier domain for projecting the approximation onto a relaxation of the polytope of legal marginal distributions. We demonstrate the effectiveness of our approach on a real camera-based multi-person tracking scenario. [abs] [ pdf ][ bib ] &copy JMLR 2009. ( edit, beta )

ICML Conference 2009 Conference Paper

Hilbert space embeddings of conditional distributions with applications to dynamical systems

• Le Song
• Jonathan Huang
• Alexander J. Smola
• Kenji Fukumizu

In this paper, we extend the Hilbert space embedding approach to handle conditional distributions. We derive a kernel estimate for the conditional embedding, and show its connection to ordinary embeddings. Conditional embeddings largely extend our ability to manipulate distributions in Hilbert spaces, and as an example, we derive a nonparametric method for modeling dynamical systems where the belief state of the system is maintained as a conditional embedding. Our method is very general in terms of both the domains and the types of distributions that it can handle, and we demonstrate the effectiveness of our method in various dynamical systems. We expect that conditional embeddings will have wider applications beyond modeling dynamical systems.

NeurIPS Conference 2009 Conference Paper

Riffled Independence for Ranked Data

• Jonathan Huang
• Carlos Guestrin

Representing distributions over permutations can be a daunting task due to the fact that the number of permutations of n objects scales factorially in n. One recent way that has been used to reduce storage complexity has been to exploit probabilistic independence, but as we argue, full independence assumptions impose strong sparsity constraints on distributions and are unsuitable for modeling rankings. We identify a novel class of independence structures, called riffled independence, which encompasses a more expressive family of distributions while retaining many of the properties necessary for performing efficient inference and reducing sample complexity. In riffled independence, one draws two permutations independently, then performs the riffle shuffle, common in card games, to combine the two permutations to form a single permutation. In ranking, riffled independence corresponds to ranking disjoint sets of objects independently, then interleaving those rankings. We provide a formal introduction and present algorithms for using riffled independence within Fourier-theoretic frameworks which have been explored by a number of recent papers.

NeurIPS Conference 2007 Conference Paper

Efficient Inference for Distributions on Permutations

• Jonathan Huang
• Carlos Guestrin
• Leonidas Guibas

Permutations are ubiquitous in many real world problems, such as voting, rankings and data association. Representing uncertainty over permutations is challenging, since there are n! possibilities, and typical compact representations such as graphical models cannot efficiently capture the mutual exclusivity con- straints associated with permutations. In this paper, we use the “low-frequency” terms of a Fourier decomposition to represent such distributions compactly. We present Kronecker conditioning, a general and efficient approach for maintaining these distributions directly in the Fourier domain. Low order Fourier-based approximations can lead to functions that do not correspond to valid distributions. To address this problem, we present an efficient quadratic program defined directly in the Fourier domain to project the approximation onto a relaxed form of the marginal polytope. We demonstrate the effectiveness of our approach on a real camera-based multi-people tracking setting.