NeurIPS 2026 Papers

Conference on Neural Information Processing Systems

Decision breakdown

6,437papers

Counted from the official paper list; may differ slightly from the number the conference announced.

  • Oral
    991.5%
  • Spotlight
    2403.7%
  • Poster
    6,09894.7%

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Topic: Diffusion Models · 661 papers · Reset filters

Action-On-Item Preference Flow: A Shared Event Schema for Predictive and Generative Personalization

Parthiv Chatterjee, Kashish Kanjariya, Vashisht Purani, Sourish Dasgupta, Tanmoy Chakraborty

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Personalization histories vary across domains because surface actions and objectives differ: users watch or skip movies, click or ignore news, or request recommendation, summarization, question answering, or response generation. Rather than build a separate history encoder for each action space, we rewrite native interactions into a shared *action-on-item event schema*: a specific action on a specific item becomes positive, negative, or command-like evidence over a target-locus embedding whose geometry induces item-kind abstraction. Task requests become generalized commands over the active item-side abstraction. The modeling problem is how this evidence enters a user-specific state, persists, and is read out by the active command. We formulate the Multi-Timescale State Hypothesis (MTSH), where signed and command-like evidence flows through long-term stable interests, recency-sensitive short-term interests, and bursty episodic traces. We instantiate MTSH with $\texttt{PerTIDE}$, an action-conditioned multi-timescale encoder that learns a user-specific preference-history state and uses command-conditioned readout to produce a task-ready state. We evaluate $\texttt{PerTIDE}$ on MovieLens, MIND, and PENS for prediction, and PENS/OpenAI-Reddit for generation. $\texttt{PerTIDE}$ improves over the strongest baselines without explicit trace factorization by +2.36/+3.47, +10.05/+9.01, and +0.90/+1.42 MRR/nDCG on MovieLens, MIND, and PENS; and over the strongest two-shot large language model by +0.10/+0.18 and +0.04/+0.19 PerSEval-JSD/PerSEval-METEOR on PENS and OpenAI-Reddit. Removing action conditioning and command-conditioned readout degrades MIND by 6.52 MRR / 9.13 HR@10 and 4.14 MRR / 4.42 HR@10. Trace diagnostics show L/S/E specialization, while the full $L+S+E$ model is strongest under mixed stable, recency-sensitive, and episodic command evidence. These results support action-conditioned multi-timescale preference flow as a reusable user-history encoding principle.

Poster
Accelerating Video Inverse Problem Solvers with Autoregressive Diffusion Models

Taesung Kwon, JongHyun Park, Hyungjin Chung, Jong Chul Ye

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Diffusion models provide powerful priors for zero-shot video inverse problems, but their real-time deployment is hindered by two inefficiencies: high initial latency caused by holistic video restoration, and low throughput resulting from multiple VAE passes to enforce measurement consistency in pixel space. To overcome these limitations, we propose Autoregressive Video Inverse problem Solver (AVIS). The AVIS framework leverages autoregressive video diffusion models to restore videos in a streaming manner, naturally eliminating latency bottlenecks. Specifically, AVIS initializes reverse diffusion with a measurement-consistent estimate, reducing the required sampling steps. Compared to leading non-autoregressive solvers, AVIS drastically reduces initial latency from 114s to 4s and increases throughput from 0.71 to 1.18 FPS while achieving superior restoration quality. We further introduce a highly accelerated variant, dubbed AVIS *Flash*, that enforces measurement consistency solely on the *first* chunk. AVIS *Flash* substantially boosts throughput to 5.91 FPS on a single RTX 4090 GPU while maintaining competitive performance and achieving a favorable efficiency–performance trade-off, paving the way toward real-time deployment.

Poster
Accelerating Rectified Flow Models via Trajectory-Aware Caching

Xiao Liu, Kai Liu, Naiyang Guan, Hongliang Lu, Zhixin Wang, Zhikai Chen, Renjing Pei, Yulun Zhang

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Diffusion and rectified flow (RF) models generate high-fidelity images and videos, but their iterative velocity-field evaluations are computationally expensive. Existing caching methods accelerate sampling by skipping timesteps, yet their coarse approximations introduce accumulated errors over long skip intervals and degrade quality under aggressive acceleration. We propose \textbf{TACache (Trajectory-Aware Cache)}, a training-free acceleration framework following a \textbf{skip-then-compensate} paradigm. TACache performs an orthogonal decomposition of discrete velocity acceleration along the RF trajectory into parallel and orthogonal components, isolating the magnitude and directional sources of per-step approximation error. The framework operates in two stages: \emph{offline}, cumulative variation thresholds on the magnitude and direction indicators yield the skipping schedule and bound how far each skipped interval may extend; \emph{online}, at each skipped step the offline statistics are combined with the sample's historical orthogonal direction to reconstruct the skipped velocity without additional forward passes. Experiments on BAGEL, FLUX.1-dev, and Wan2.1-1.3B show that TACache achieves up to $4.14\times$ speedup on text-to-image generation and $2.11\times$ speedup on text-to-video generation, with consistent improvements over prior cache-based methods on all reference-based fidelity metrics. Code will be released soon.

Poster
Accelerating Diffusion Language Models via Structured Suffix Modeling

Zifeng Cheng, Keda Li, Zhiwei Jiang, Cong Wang, Fei Shen, Qing Gu

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Diffusion Language Models (DLMs) exhibit strong parallel decoding capabilities by denoising multiple tokens in a single generation step. However, this parallelism comes with substantial computational overhead, as each step requires interactions with all suffix tokens. Existing methods typically reduce this cost by retaining only a local suffix window as a substitute for the full suffix. Despite their effectiveness, these methods overlook the structural heterogeneity across suffix regions and re-initialize suffix tokens with identical representations at each timestep. To this end, we propose a structured suffix modeling method for efficient DLM inference. Specifically, we divide the suffix into three regions, i.e., the local, middle, and tail regions, and retain different numbers of suffix tokens in each region according to their structural roles. Moreover, we incorporate the decoding results from the previous step into the suffix token representations at the current step, allowing them to carry evolving denoising information across generation steps. Notably, our method is training-free and orthogonal to several existing acceleration techniques, such as parallel decoding strategies and KV cache. Empirical results across multiple benchmarks on three DLMs demonstrate that our method can further accelerate DLM inference and, in most cases, also improve task performance. In particular, in long-sequence inference, our method achieves up to a \(72.16\times\) speedup when combined with other acceleration techniques.

Poster
AbFlowNet: Optimizing Antibody-Antigen Binding Energy via Diffusion-GFlowNet Fusion

Abrar Rahman Abir, Haz Sameen Shahgir, Rownok Z Ratul, Toki Tahmid, Greg Ver Steeg, Yue Dong

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Complementarity Determining Regions (CDRs) are critical segments of an antibody that facilitate binding to specific antigens. Current computational methods for CDR design rely on reconstruction losses and do not jointly optimize binding energy, a crucial metric of antibody efficacy. Rather, binding energy optimization is performed via computationally expensive Online Reinforcement Learning (RL) pipelines that rely heavily on unreliable binding-energy estimators. In this paper, we propose AbFlowNet, a novel generative framework that integrates GFlowNet with Diffusion models. By framing each diffusion step as a state in the GFlowNet framework, AbFlowNet jointly optimizes standard diffusion losses and binding energy by directly incorporating energy signals into the training process, thereby unifying diffusion and reward optimization in a single procedure. Experimental results show that AbFlowNet outperforms the base diffusion model by 3.06% in amino acid recovery, 20.40% in geometric reconstruction (RMSD), and 3.60% in binding energy improvement ratio. ABFlowNet also decreases Top-1 total energy and binding energy errors by 24.8% and 38.1%, which is competitive with AbDPO's expensive online RL optimization without pseudo-labeling the test dataset or requiring computationally expensive synthetic CDR sampling.

Poster
ART for Diffusion Sampling: A Reinforcement Learning Approach to Timestep Scheduling

Yilie Huang, Wenpin Tang, XUNYU ZHOU

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We consider time discretization for score-based diffusion models to generate samples from a learned reverse-time dynamic on a finite grid. Uniform and hand-crafted grids can be suboptimal given a budget on the number of time steps. We introduce Adaptive Reparameterized Time (ART), which controls the clock speed of a reparameterized time variable to redistribute computation along the sampling trajectory while preserving the terminal time, with the objective of minimizing the aggregate Euler discretization error. We derive a randomized companion ART-RL that recasts ART as a continuous-time reinforcement learning problem with Gaussian policies, and prove a two-directional bridge between the two: the deterministic ART optimum lifts to an optimal Gaussian policy, and conversely any optimal Gaussian policy must recover the ART control through its mean. This bridge turns continuous-time actor--critic learning into a principled, rather than heuristic, route to the deterministic timestep optimum. Within the official EDM pipeline, ART-RL improves FID on CIFAR--10 across a wide range of budgets; after one-time offline training, the distilled deterministic schedule transfers without retraining to AFHQv2, FFHQ, and ImageNet at no extra inference cost.

Poster
AR-Edit: Training-Free Streaming Video Editing without Inversion

Hovhannes Margaryan, Vicky Kalogeiton, Quentin Bammey, Christian Sandor

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Editing a video stream in real time, without access to future frames, is essential for interactive applications. Existing training-free video editing methods, however, assume full offline access to the entire sequence, while streaming approaches either rely on additional training or are limited to specific editing techniques. We show that this limitation can be removed by analyzing the self-attention dynamics of DMD-distilled autoregressive video diffusion models. We uncover a key asymmetry: queries and keys remain stable and aligned with their source counterparts across denoising timesteps, while values diverge and encode the evolving content. This observation leads to a simple mechanism: a single forward pass suffices to capture source identity in the value features, which can be reused throughout generation. Starting from pure Gaussian noise and injecting only these source values reconstructs the input with fidelity matching inversion-based methods, effectively eliminating inversion. Based on this insight, we introduce AR-Edit, a training-free, inversion-free method that caches source values once and selectively injects them during autoregressive denoising, enabling real-time, structure-preserving streaming video editing with minimal overhead. Code will be released.

Poster
ANCRe: Adaptive Neural Connection Reassignment for Efficient Depth Scaling

Yilang Zhang, Bingcong Li, Niao He, Georgios Giannakis

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Scaling network depth has been a central driver behind the success of modern foundation models, yet recent investigations suggest that deep layers are often underutilized. This paper revisits the default mechanism for deepening neural networks, namely residual connections, from an optimization perspective. On a motivating example, rigorous analysis proves that the layout of residual connections can fundamentally shape convergence behavior, and even induces an *exponential* gap in convergence rates. Prompted by this insight, we introduce adaptive neural connection reassignment (ANCRe), a principled and lightweight framework that parameterizes and learns residual connectivities from the data. ANCRe adaptively reassigns residual connections with negligible computational and memory overhead (<1%), while enabling more effective utilization of network depth. Extensive numerical tests across pre-training of large language models, diffusion models, and deep ResNets demonstrate consistently accelerated convergence, boosted performance, and enhanced depth efficiency over conventional residual connections.

Poster
ALAM: Algebraically Consistent Latent Transitions for Vision-Language-Action Models

Zuojin Tang, Haoyun Liu, Xinyuan Chang, Changjie Wu, Dongjie Huo, Yandan Yang, Bin Liu, Zhejia Cai, Feng Xiong, Mu Xu, Jiachen Luo, De Ma, Zhiheng Ma, Gang Pan

Expand abstract

Vision-language-action (VLA) models remain constrained by the scarcity of action-labeled robot data, whereas action-free videos provide abundant evidence of how the physical world changes. Latent action models offer a promising way to extract such priors from videos, but reconstruction-trained latent codes are not necessarily suitable for policy generation: they may predict future observations while lacking the structure needed to be reused or generated coherently with robot actions. We introduce \textbf{ALAM} (\textbf{A}lgebraic \textbf{L}atent \textbf{A}ction \textbf{M}odel), an Algebraically Consistent Latent Action Model that turns temporal relations in action-free video into structural supervision. Given frame triplets, ALAM learns latent transitions that are grounded by reconstruction while being regularized by composition and reversal consistency, encouraging a locally additive transition space. For downstream VLA learning, we freeze the pretrained encoder and use its latent transition sequences as auxiliary generative targets, co-generated with robot actions under a joint flow-matching objective. This couples structured latent transitions with flow-based policy generation, allowing the policy to exploit ALAM's locally consistent transition geometry without requiring latent-to-action decoding. Representation probes show that ALAM reduces additivity and reversibility errors by 25--85$\times$ over unstructured latent-action baselines and improves long-horizon cumulative reconstruction. When transferred to VLA policies, ALAM raises the average success rate from 47.9\% to 85.0\% on MetaWorld MT50 and from 94.1\% to 98.1\% on LIBERO, with consistent gains on real-world manipulation tasks. Ablations further confirm that the strongest improvements arise from the synergy between algebraically structured latent transitions and joint flow matching.

Poster
AHPA: Adaptive Hierarchical Prior Alignment for Diffusion Transformers

Ruibin Min, Yexin Liu, Aimin PAN, Changsheng Lu, Jiafei Wu, kelu Yao, Xiaogang Xu, Harry Yang

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Representation alignment has recently emerged as an effective paradigm for accelerating Diffusion Transformer training. Despite their success, existing alignment methods typically impose a fixed supervision target or a fixed alignment granularity throughout the entire denoising trajectory, whether the guidance is provided by external vision encoders, internal self-representations, or VAE-derived features. We argue that such timestep-agnostic alignment is suboptimal because the useful granularity of representation supervision changes systematically with the signal-to-noise ratio. In high-noise regimes, diffusion models benefit more from coarse semantic and layout-level anchoring, whereas in low-noise regimes, the training signal should emphasize spatially detailed and structurally faithful refinement. This non-stationary alignment behavior creates a representational mismatch for static single-level supervisors. To address this issue, we propose Adaptive Hierarchical Prior Alignment (AHPA), a lightweight alignment framework that exploits the hierarchical representations naturally embedded in the frozen VAE encoder. Instead of using only a single compressed latent as the alignment target, AHPA extracts multi-level VAE features that provide complementary priors ranging from local geometry and spatial topology to coarse semantic layout. A timestep-conditioned Dynamic Router adaptively selects and weights these hierarchical priors along the denoising trajectory, thereby synchronizing the alignment granularity with the model's evolving training needs. Extensive experiments show that AHPA improves convergence and generation quality over baselines and incurs no additional inference cost while avoiding external encoder supervision during training.

Poster
ABC: Any-Subset Autoregression via Non-Markovian Diffusion Bridges in Continuous Time and Space

Gabe Guo, Thanawat Sornwanee, Lutong Hao, Elon Litman, Stefano Ermon, Jose Blanchet

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Generative modeling continuous-time, continuous-space stochastic processes (e.g., videos, weather forecasts) conditioned on partial observations (e.g., first and last frames) is a fundamental challenge. Existing approaches, (e.g., diffusion models), suffer from key limitations: (1) noise-to-data evolution fails to capture structural similarity between states close in physical time and has unstable integration in low-step regimes; (2) random noise injected is insensitive to the physical process's time elapsed, resulting in incorrect dynamics; (3) they overlook conditioning on arbitrary subsets of states (e.g., irregularly sampled timesteps, future observations). We propose ABC: Any-Subset Autoregressive Models via Non-Markovian Diffusion Bridges in Continuous Time and Space. Crucially, we model the process with one continual SDE whose time variable and intermediate states track the real time and process states. This has provable advantages: (1) the starting point for generating future states is the already-close previous state, rather than uninformative noise; (2) random noise injection scales with physical time elapsed, encouraging physically plausible dynamics with similar time-adjacent states. We derive SDE dynamics via changes-of-measure on path space, yielding another advantage: (3) path-dependent conditioning on arbitrary subsets of the state history and/or future. To learn these dynamics, we derive a path- and time-dependent extension of denoising score matching. Our experiments show ABC's superiority to competing methods on multiple domains, including video generation and weather forecasting.

Poster
A multi-scale information geometry reveals the structure of mutual information in neural populations

Simone Azeglio, Steeve Laquitaine, Ulisse Ferrari, Matthew Chalk

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Understanding how neural population responses represent sensory information is a central problem in systems neuroscience. One approach is to define a representational geometry on stimulus space in which distances reflect how reliably stimuli can be distinguished from neural activity. However, different constructions of these distances can lead to qualitatively different conclusions about the neural code. Here, we show that a unique Riemannian representational geometry emerges from first principles governing how distances contract as stimulus resolution is lost through coarse-graining. This results in a multi-scale extension of the Fisher information metric, capturing encoding structure from fine stimulus details to coarse global distinctions. The resulting geometry is exactly related to the mutual information encoded by the population: well encoded stimulus directions -- those contributing more to mutual information -- are expanded, whereas poorly encoded directions are contracted. The metric tensor can be estimated using diffusion models, making the framework practical for large neural populations and high-dimensional stimuli. Applied to visual cortical responses to natural images, the eigenvectors of the metric tensor identify stimulus variations that contribute most to information transmission, yielding interpretable features that are robust to modelling choices. Together, these results provide a principled, information-theoretic framework for characterising neural population codes.

Oral
A Theory on Flow Matching with Neural Networks

Yihan He, Qishuo Yin, Yuan Cao, Jianqing Fan, Han Liu

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In this work, we develop theoretical foundation for flow matching with neural-network–parameterized conditional velocity fields. We establish convergence guarantees for gradient descent in the over-parameterized 2-layered ReLU neural network regime. We derive generalization bounds for the conditional velocity-field matching objective. Building on these results, we provide Wasserstein-distance guarantees for the samples generated by the induced flow. Our analysis is based on generalization bound for multi-task representation learning with unbounded losses, which may be of independent interest beyond flow-based generative modeling. These theoretical results are validated through extensive experiments on both synthetic and real-world image benchmarks.

Poster
A Theoretical Analysis of Why Masked Diffusion Models Mitigate the Reversal Curse

Moongyu Jeon, Sangwoo Shin, BumJun Kim, Kyelim Lee, Albert No

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Autoregressive language models (ARMs) suffer from the reversal curse: after learning "$A$ is $B$," they often fail on the reverse query "$B$ is $A$." Masked diffusion language models (MDMs) exhibit this failure in a much weaker form, but the underlying reason has remained unclear. A common explanation attributes this mitigation to their any-order masked training objective. However, observing "$[\textnormal{\textbf{M}}]$ is $B$" during training teaches recovery of $A$ from $B$ in one positional configuration, and does not by itself explain why the learned evidence should transfer to the reverse prompt "$B$ is $[\textnormal{\textbf{M}}]$." We provide a theoretical analysis showing that this transfer arises from a parameter-level coupling between forward and reverse positional conditionals: shared Transformer parameters store token-pair evidence, while relative positional encodings route attention through queries and keys without changing the value-side evidence being retrieved. In a one-layer MDM, we prove that forward masked training strengthens evidence that is reusable in reverse queries, induces correlated forward--reverse attention routes, and yields a positively aligned shared-storage gradient component that decreases the reverse loss to first order. Controlled one-layer experiments and large-scale LLaDA/Dream experiments verify these signatures and show that they translate into improved reverse prediction.

Poster
A Steerable Deep Network for Model-Free Diffusion MRI Registration

Gianfranco Cortes, Xiaoda Qu, Baba C. Vemuri

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Nonrigid registration is vital to medical image analysis but remains challenging for diffusion MRI (dMRI) due to its high-dimensional, spatio-angular dependence. We present a novel, geometric deep learning framework for {\it model-free}, nonrigid registration of raw dMRI data. The dMRI registration problem is formulated in the native spatio-angular acquisition space, which exhibits a natural symmetry to the group of 3D roto-translations, denoted by $\mathrm{SE}(3)$. A by-product of this design choice is freedom from having to augment the data with roto-translated versions of itself. Our second novelty is the loss function formulation, based on the maximum mean discrepancy (MMD) loss used to compare two probability density functions. We apply this loss in the Fourier space, where it becomes the well-known weighted sum-of-squared differences (SSD) loss with the weights being the Fourier transform of a reproducing kernel Hilbert space (RKHS) kernel. Experimental results on HCP and OASIS-3 clinical-grade dMRI data demonstrate competitive performance compared to SOTA approaches, with the added advantage of bypassing the overhead for estimating derived representations. This work establishes a foundation for data-driven, geometry-aware dMRI registration directly in the acquisition space.

Poster
A Solver-Efficient Neural Adversarial Attack on Subgraph Matching Models

Ninad Gandhi, Mayukh Mondal, Brian S Mackwan, Soumen Chakrabarti, Abir De

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Neural subgraph matching (NSGM) models are widely used for graph retrieval, where relevance labels for query–corpus pairs are determined by whether the query graph is a subgraph of the corpus graph. Despite widespread applications, the adversarial robustness of such models remains underexplored. In principle, adversarial attacks should induce minimal shift of the instance distribution and the target labels. However, in NSGM, a single edge insertion or deletion can flip relevance labels. Detecting or controlling label flips requires repeated calls to potentially expensive combinatorial solvers. Responding to this challenge, we propose SEAGRAM, a solver-efficient adversarial attack method. It learns to detect non-critical node pairs whose perturbations will likely preserve relevance labels, thereby avoiding solver calls during test time. We further employ an active learning strategy, which reduces the solver calls also during training. Experiments show that SEAGRAM significantly worsens the performance of existing models.

Poster
A Mean-Field Framework for Inference-Time Distributional Control of Diffusion Models

Samuel Howard, Nikolas Nüsken

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Diffusion models are increasingly used as controllable samplers, whose generations can be steered at inference time according to a chosen reward function. While such rewards are typically defined on individual samples, for many applications it is desirable to steer according to distribution-level rewards, for example to calibrate with population-level information or to encourage diversity. In both cases, simply incorporating the reward gradient into the dynamics, while often effective, comes with few theoretical guarantees on the sampled distribution. For pointwise rewards, recent work has therefore sought to develop a principled framework for targeting a prescribed tilted distribution using particle reweighting. However, an analogous theoretically-grounded approach for distributional rewards is currently lacking. In this work, we formulate inference-time distributional control as targeting a tilted measure under a mean-field framework, and derive a weighted interacting particle scheme to target it in a principled manner. Our framework recovers pointwise-reward steering as a special case, while providing a theoretical foundation for existing batch-level steering methods. Empirically, we verify that the procedure correctly targets the prescribed distribution in tractable low-dimensional settings, and investigate its behaviour in higher-dimensional protein conformation tasks.

Poster
A Favorable Regime Between ODE and SDE for Few-Step Diffusion Sampling

YIhao Bu, Dan Lian, Zhenguo Gao

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Few-step diffusion sampling sharpens the tension between ODE and SDE dynamics. ODE samplers are stable but can lose diversity, while the standard SDE endpoint can become unreliable at low numbers of function evaluations (NFE). The challenge is therefore not simply whether stochasticity should be added, but which driver properties allow stochastic correction to contribute diffusion without losing finite-step control. We show that this tradeoff is governed by two driver-level quantities, the asymptotic covariance $Q$, which sets the effective diffusion level on the ODE-to-SDE spectrum, and the Poisson solution norm $C_\chi$, which controls the finite-step remainder. Gaussian drivers have $C_\chi = \infty$, so this finite-step remainder is not uniformly controlled by the same bound. Balancing the diffusion level set by $Q$ with the finite-step control set by $C_\chi$ formalizes a favorable regime for bounded structured drivers with intermediate diffusion strength. This regime directly gives a structured correction method, instantiated as Fast-Driver Sampler (FDS) with the shuffled-Lorenz driver. Across DiT-XL/2 and EDM2, FDS establishes a stronger low-NFE frontier among evaluated training-free samplers, improving ODE baselines while avoiding the degradation of the SDE endpoint.

Poster
$h$-control: Training-Free Camera Control via Block-Conditional Gibbs Refinement

Yuzhu Wang, Xi Ye, Duo Su, Yangyang Xu, Jun Zhu

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Training-free camera control for pretrained flow-matching video generators is a partial-observation inverse problem: a depth-warped guidance video supplies noisy evidence on a subset of latent sites, which the sampler must reconcile with the pretrained prior. Existing methods struggle to balance the trade-off between trajectory adherence and visual quality and the heuristic guidance-strength tuning lacks robustness. We propose $h$-control, which resolves this dilemma through a structural change to the sampler: each outer hard-replacement guidance step is augmented with an inner-loop block-conditional pseudo-Gibbs refinement on the unobserved complement at the same noise level, with provable convergence to the partial-observation conditional data law. To accelerate convergence on high-dimensional video latents, we exploit their conditional locality, partitioning the unobserved complement into 3D patches, each tracked by a custom mixing indicator that adaptively freezes converged patches. On RealEstate10K and DAVIS, $h$-control attains the best FVD against all seven training-free and training-based competitors, outperforming every training-free baseline on every reported metric.

Poster
$\text{PartConcepts}$: A Unified Mechanism for Fine-Grained Part Localization and Generation

Vaibhav Agrawal, Varghese P Kuruvilla, Harsh Rangwani, Ravi Kiran Sarvadevabhatla

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While text-to-image (T2I) diffusion models exhibit strong semantic disentanglement at the object level, they struggle to localize fine-grained object parts. Although the latent visual features in these models are sufficiently fine-grained, the text–image interaction (cross-attention) fails to effectively exploit this information. This results in coarse and ambiguous localization, particularly for spatially distinct components such as `left` and `right` limbs. To address this limitation, we introduce **PartConcepts, a mechanism that encodes textual part descriptions into compact, learnable representations**. These PartConcept tokens are trained to selectively attend to their corresponding part regions in the image. To evaluate the part-level understanding of PartConcept tokens, we first probe its effectiveness for *part segmentation*. We then evaluate whether the improved localization enables *fine-grained instruction following* in T2I generation. On the standard **Open-Vocabulary Part Segmentation (OVPS) benchmark, our method outperforms dedicated segmentation baselines**, establishing a new state-of-the-art. We further evaluate our method on the more complex Pascal-Part benchmark for *part instance segmentation*, which contains fine-grained spatial annotations (e.g. `left lower arm`). Here, we outperform all baselines by a very significant margin. Finally, our qualitative and quantitative results show that this strong localization of PartConcept tokens directly enables *fine-grained instruction following* in T2I generation: the textual attributes (e.g., color) *inherently* bind well to corresponding PartConcept tokens, without explicit attribute control mechanisms. This indicates that PartConcept tokens compose seamlessly with other text tokens, highlighting their applicability for **fine-grained text-based generative control**.

Poster