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Chenfeng Xu

55 accepted papers

2026

CaptionQA: Is Your Caption as Useful as the Image Itself?

CVPR 2026

Image captions serve as efficient surrogates for visual content in multimodal systems such as retrieval, recommendation, multi-step agentic inference pipelines. Yet current evaluation practices miss a fundamental question: Can captions stand-in for images in real downstream tasks? We propose a utili

Cited by 0SourcecodeScholar
2026

LoSA: Locality Aware Sparse Attention in Diffusion Language Models

ICML 2026poster

Block-wise diffusion language models (DLMs) generate multiple tokens in parallel, offering a promising alternative to autoregressive decoding. However, their inference efficiency remains bottlenecked by memory-bound attention in long-context scenarios. Naïve sparse attention is ineffective for DLMs …

Cited by 0SourceScholar
2026

OXE-AugE: A Large-Scale Robot Augmentation of OXE for Scaling Cross-Embodiment Policy Learning

ICML 2026spotlight

Large and diverse datasets are needed for training generalist robot policies that have potential to control a variety of robot embodiments--robot arm and gripper combinations--across diverse tasks and environments. As re-collecting demonstrations and retraining for each new hardware platform are pro…

Cited by 0SourceScholar
2026

Quant VideoGen: Auto-Regressive Long Video Generation via 2-Bit KV-Cache Quantization

ICML 2026poster

Despite rapid progress in auto-regressive video diffusion, we identify an emerging system–algorithm bottleneck that limits both deployability and generation quality: KV-cache memory. In auto-regressive video generation models, the KV-cache grows with generation history and quickly dominates GPU memo…

Cited by 0SourceScholar
2026

REAR: Test-time Preference Realignment through Reward Decomposition

ICML 2026poster

Aligning large language models (LLMs) with diverse user preferences is a critical yet challenging task. While post-training methods can adapt models to specific needs, they often require costly data curation and additional training. Test-time scaling (TTS) presents an efficient, training-free altern…

Cited by 0SourceScholar
2026

Reimagination with Test-Time Observation Interventions: Distractor-Robust World Model Predictions for Visual Model Predictive Control

ICRA 2026poster

World models enable robots to “imagine” future observations given current observations and planned actions, and have been increasingly adopted as generalized dynamics models to facilitate robot learning. Despite their promise, these models remain brittle when encountering novel visual distractors su…

2026

Residual Context Diffusion Language Models

ICML 2026poster

Diffusion Large Language Models (dLLMs) have emerged as a promising alternative to purely autoregressive language models because they can decode multiple tokens in parallel. However, state-of-the-art block-wise dLLMs rely on a ``remasking" mechanism that decodes only the most confident tokens and di…

Cited by 0SourceScholar
2026

ThunderAgent: A Fast, Simple, and Program-Aware Agentic Inference System

ICML 2026spotlight

Large language models (LLMs) are now used to power complex multi-turn agentic workflows. Existing services run agentic inference by assembling isolated components: an LLM inference engine (e.g., vLLM) and a tool orchestrator (e.g., Kubernetes). Although agentic workflows involve multiple LLM and too…

Cited by 0SourceScholar
2026

When RL Meets Adaptive Speculative Training: A Unified Training-Serving System

ICML 2026poster

Speculative decoding can significantly accelerate LLM serving, but its real-world benefits often erode due to training–serving mismatch and non-stationary traffic. Unlike previous systems that decouple speculator training from inference, we present a unified training–serving system, Aurora, that clo…

Cited by 0SourceScholar
2025

A Lesson in Splats: Teacher-Guided Diffusion for 3D Gaussian Splats Generation with 2D Supervision

ICCV 2025poster

We present a novel framework for training 3D image-conditioned diffusion models using only 2D supervision. Recovering 3D structure from 2D images is inherently ill-posed due to the ambiguity of possible reconstructions, making generative models a natural choice. However, most existing 3D generative…

Cited by 0SourcePDFScholar
2025

Angles Don’t Lie: Unlocking Training‑Efficient RL Through the Model’s Own Signals

NeurIPS 2025spotlight

Current Reinforcement Fine-tuning (RFT) paradigms for Large Language Models (LLMs) suffer from sample inefficiency due to the redundant exposure of identical queries under uniform data sampling. While previous work has explored curriculum learning via heuristic difficulty metrics, these strategies e…

Cited by 0SourceScholar
2025

Bridging Viewpoint Gaps: Geometric Reasoning Boosts Semantic Correspondence

CVPR 2025poster

Finding semantic correspondences between images is a challenging problem in computer vision, particularly under significant viewpoint changes. Previous methods rely on semantic features from pre-trained 2D models like Stable Diffusion and DINOv2, which often struggle to extract viewpoint-invariant f…

Cited by 0SourcePDFScholar
2025

CompGS: Unleashing 2D Compositionality for Compositional Text-to-3D via Dynamically Optimizing 3D Gaussians

CVPR 2025poster

Recent breakthroughs in text-guided image generation have significantly advanced the field of 3D generation. While generating a single high-quality 3D object is now feasible, generating multiple objects with reasonable interactions within a 3D space, a.k.a. compositional 3D generation, presents subs…

Cited by 4SourcePDFScholar
2025

CooPre: Cooperative Pretraining for V2X Cooperative Perception

IROS 2025

Existing Vehicle-to-Everything (V2X) cooperative perception methods rely on accurate multi-agent 3D annotations. Nevertheless, it is time-consuming and expensive to collect and annotate real-world data, especially for V2X systems. In this paper, we present a self-supervised learning framwork for V2X

Cited by 12SourcecodeScholar
2025

DeSiRe-GS: 4D Street Gaussians for Static-Dynamic Decomposition and Surface Reconstruction for Urban Driving Scenes

CVPR 2025poster

We present DeSiRe-GS, a self-supervised gaussian splatting representation, enabling effective static-dynamic decomposition and high-fidelity surface reconstruction in complex driving scenarios. Our approach employs a two-stage optimization pipeline of dynamic street Gaussians. In the first stage, we…

2025

Dobi-SVD: Differentiable SVD for LLM Compression and Some New Perspectives

ICLR 2025poster

Large language models (LLMs) have sparked a new wave of AI applications; however, their substantial computational costs and memory demands pose significant challenges to democratizing access to LLMs for a broader audience. Singular Value Decomposition (SVD), a technique studied for decades, offers a…

Cited by 0SourcePDFScholar
2025

Looking Backward: Streaming Video-to-Video Translation with Feature Banks

ICLR 2025poster

This paper introduces StreamV2V, a diffusion model that achieves real-time streaming video-to-video (V2V) translation with user prompts. Unlike prior V2V methods using batches to process limited frames, we opt to process frames in a streaming fashion, to support unlimited frames. At the heart o…

2025

Segment Any Motion in Videos

CVPR 2025poster

Moving object segmentation is a crucial task for achieving a high-level understanding of visual scenes and has numerous downstream applications. Humans can effortlessly segment moving objects in videos. Previous work has largely relied on optical flow to provide motion cues; however, this approach o…

2025

Sparse Video-Gen: Accelerating Video Diffusion Transformers with Spatial-Temporal Sparsity

ICML 2025poster

Diffusion Transformers (DiTs) dominate video generation but their high computational cost severely limits real-world applicability, usually requiring tens of minutes to generate a few seconds of video even on high-performance GPUs. This inefficiency primarily arises from the quadratic computational…

Cited by 11SourcePDFScholar
2025

Sparse VideoGen2: Accelerate Video Generation with Sparse Attention via Semantic-Aware Permutation

NeurIPS 2025spotlight

Diffusion Transformers (DiTs) are essential for video generation but suffer from significant latency due to the quadratic complexity of attention. By computing only critical tokens, sparse attention reduces computational costs and offers a promising acceleration approach. However, we identify that…

Cited by 0SourcecodeScholar
2025

StreamDiffusion: A Pipeline-level Solution for Real-Time Interactive Generation

ICCV 2025poster

We introduce StreamDiffusion, a real-time diffusion pipeline designed for streaming image generation. Existing diffusion models are adept at creating images from text or image prompts, yet they often fall short in real-time interaction. This limitation becomes particularly evident in scenarios invol…

2025

TrajSSL: Trajectory-Enhanced Semi-Supervised 3D Object Detection

ICRA 2025

Semi-supervised 3D object detection is a common strategy employed to circumvent the challenge of manually labeling large-scale autonomous driving perception datasets. Pseudo-labeling approaches to semi-supervised learning adopt a teacher-student framework in which machine-generated pseudo-labels on

Cited by 0SourceScholar
2025

WOMD-Reasoning: A Large-Scale Dataset for Interaction Reasoning in Driving

ICML 2025poster

Language models uncover unprecedented abilities in analyzing driving scenarios, owing to their limitless knowledge accumulated from text-based pre-training. Naturally, they should particularly excel in analyzing rule-based interactions, such as those triggered by traffic laws, which are well documen…

2025

X-Drive: Cross-modality Consistent Multi-Sensor Data Synthesis for Driving Scenarios

ICLR 2025poster

Recent advancements have exploited diffusion models for the synthesis of either LiDAR point clouds or camera image data in driving scenarios. Despite their success in modeling single-modality data marginal distribution, there is an under- exploration in the mutual reliance between different modaliti…

2024

3DiffTection: 3D Object Detection with Geometry-Aware Diffusion Features

CVPR 2024poster

3DiffTection introduces a novel method for 3D object detection from single images utilizing a 3D-aware diffusion model for feature extraction. Addressing the resource-intensive nature of annotating large-scale 3D image data our approach leverages pretrained diffusion models traditionally used for 2D…

Cited by 13SourcePDFScholar
2024

CVT-Occ: Cost Volume Temporal Fusion for 3D Occupancy Prediction

ECCV 2024poster

"Vision-based 3D occupancy prediction is significantly challenged by the inherent limitations of monocular vision in depth estimation. This paper introduces CVT-Occ, a novel approach that leverages temporal fusion through the geometric correspondence of voxels over time to improve the accuracy of 3D…

2024

DSLO: Deep Sequence LiDAR Odometry Based on Inconsistent Spatio-temporal Propagation

IROS 2024poster

This paper introduces a 3D point cloud sequence learning model based on inconsistent spatio-temporal propagation for LiDAR odometry, termed DSLO. It consists of a pyramid structure with a spatial information reuse strategy, a sequential pose initialization module, a gated hierarchical pose refinemen…

Cited by 0SourcecodeScholar
2024

Human-oriented Representation Learning for Robotic Manipulation

RSS 2024poster

Humans inherently possess generalizable visual representations that empower them to efficiently explore and interact with the environments in manipulation tasks. We advocate that such a representation automatically arises from simultaneously learning about multiple simple perceptual skills that are…

Cited by 12SourcePDFScholar
2024

Immiscible Diffusion: Accelerating Diffusion Training with Noise Assignment

NeurIPS 2024poster

In this paper, we point out that suboptimal noise-data mapping leads to slow training of diffusion models. During diffusion training, current methods diffuse each image across the entire noise space, resulting in a mixture of all images at every point in the noise layer. We emphasize that this rando…

2024

MIRAGE: Cross-Embodiment Zero-Shot Policy Transfer with Cross-Painting

RSS 2024poster

The ability to reuse collected data and transfer trained policies between robots could alleviate the burden of additional data collection and training. While existing approaches such as pretraining plus finetuning and co-training show promise, they do not generalize to robots unseen in training. Foc…

Cited by 18SourcePDFScholar
2024

Open X-Embodiment: Robotic Learning Datasets and RT-X Models : Open X-Embodiment Collaboration

ICRA 2024

Large, high-capacity models trained on diverse datasets have shown remarkable successes on efficiently tackling downstream applications. In domains from NLP to Computer Vision, this has led to a consolidation of pretrained models, with general pretrained backbones serving as a starting point for man

Cited by 910SourcecodeScholar
2024

Open X-Embodiment: Robotic Learning Datasets and RT-X Models : Open X-Embodiment Collaboration0

ICRA 2024poster

Large, high-capacity models trained on diverse datasets have shown remarkable successes on efficiently tackling downstream applications. In domains from NLP to Computer Vision, this has led to a consolidation of pretrained models, with general pretrained backbones serving as a starting point for man…

Cited by 259SourcecodeScholar
2024

Pre-training on Synthetic Driving Data for Trajectory Prediction

IROS 2024poster

Accumulating substantial volumes of real-world driving data proves pivotal in the realm of trajectory forecasting for autonomous driving. Given the heavy reliance of current trajectory forecasting models on data-driven methodologies, we aim to tackle the challenge of learning general trajectory fore…

Cited by 13SourcecodeScholar
2024

Q-SLAM: Quadric Representations for Monocular SLAM

CoRL 2024poster

In this paper, we reimagine volumetric representations through the lens of quadrics. We posit that rigid scene components can be effectively decomposed into quadric surfaces. Leveraging this assumption, we reshape the volumetric representations with million of cubes by several quadric planes, which…

Cited by 6SourceScholar
2024

RoVi-Aug: Robot and Viewpoint Augmentation for Cross-Embodiment Robot Learning

CoRL 2024poster

Scaling up robot learning requires large and diverse datasets, and how to efficiently reuse collected data and transfer policies to new embodiments remains an open question. Emerging research such as the Open-X Embodiment (OXE) project has shown promise in leveraging skills by combining datasets inc…

Cited by 21SourceScholar
2024

Sparse Diffusion Policy: A Sparse, Reusable, and Flexible Policy for Robot Learning

CoRL 2024poster

The increasing complexity of tasks in robotics demands efficient strategies for multitask and continual learning. Traditional models typically rely on a universal policy for all tasks, facing challenges such as high computational costs and catastrophic forgetting when learning new tasks. To address…

Cited by 17SourceScholar
2024

Sparse Refinement for Efficient High-Resolution Semantic Segmentation

ECCV 2024poster

"Semantic segmentation empowers numerous real-world applications, such as autonomous driving and augmented/mixed reality. These applications often operate on high-resolution images (, 8 megapixels) to capture the fine details. However, this comes at the cost of considerable computational complexity,…

2024

What Matters to You? Towards Visual Representation Alignment for Robot Learning

ICLR 2024poster

When operating in service of people, robots need to optimize rewards aligned with end-user preferences. Since robots will rely on raw perceptual inputs, their rewards will inevitably use visual representations. Recently there has been excitement in using representations from pre-trained visual model…

Cited by 8SourcePDFScholar
2024

Zero-to-Hero: Enhancing Zero-Shot Novel View Synthesis via Attention Map Filtering

NeurIPS 2024poster

Generating realistic images from arbitrary views based on a single source image remains a significant challenge in computer vision, with broad applications ranging from e-commerce to immersive virtual experiences. Recent advancements in diffusion models, particularly the Zero-1-to-3 model, have been…

Cited by 2SourcePDFScholar
2023

ADfM-Net: An Adversarial Depth-From-Motion Network Based on Cross Attention and Motion Enhanced

RA-L 2023

The temporal consistent and accurate depth estimation for consecutive images is essential for many downstream applications. However, most existing methods only infer depth from a single image, ignoring the temporal information and important depth cues from motion in the sequence. Additionally, the d

Cited by 0SourceScholar
2023

DELFlow: Dense Efficient Learning of Scene Flow for Large-Scale Point Clouds

ICCV 2023poster

Point clouds are naturally sparse, while image pixels are dense. The inconsistency limits feature fusion from both modalities for point-wise scene flow estimation. Previous methods rarely predict scene flow from the entire point clouds of the scene with one-time inference due to the memory inefficie…

Cited by 11PDFcodeScholar
2023

NeRF-Det: Learning Geometry-Aware Volumetric Representation for Multi-View 3D Object Detection

ICCV 2023poster

We present NeRF-Det, a novel method for indoor 3D detection with posed RGB images as input. Unlike existing indoor 3D detection methods that struggle to model scene geometry, our method makes novel use of NeRF in an end-to-end manner to explicitly estimate 3D geometry, thereby improving 3D detection…

Cited by 51PDFcodeScholar
2023

Open-Vocabulary Point-Cloud Object Detection Without 3D Annotation

CVPR 2023poster

The goal of open-vocabulary detection is to identify novel objects based on arbitrary textual descriptions. In this paper, we address open-vocabulary 3D point-cloud detection by a dividing-and-conquering strategy, which involves: 1) developing a point-cloud detector that can learn a general represen…

2023

Quadric Representations for LiDAR Odometry, Mapping and Localization

RA-L 2023

Current LiDAR odometry, mapping and localization methods leverage point-wise representations of 3D scenes and achieve high accuracy in autonomous driving tasks. However, the space-inefficiency of methods that use point-wise representations limits their development and usage in practical applications

Cited by 13SourceScholar
2023

SparseFusion: Fusing Multi-Modal Sparse Representations for Multi-Sensor 3D Object Detection

ICCV 2023poster

By identifying four important components of existing LiDAR-camera 3D object detection methods (LiDAR and camera candidates, transformation, and fusion outputs), we observe that all existing methods either find dense candidates or yield dense representations of scenes. However, given that objects occ…

Cited by 77PDFcodeScholar
2023

Time Will Tell: New Outlooks and A Baseline for Temporal Multi-View 3D Object Detection

ICLR 2023top-5%

While recent camera-only 3D detection methods leverage multiple timesteps, the limited history they use significantly hampers the extent to which temporal fusion can improve object perception. Observing that existing works' fusion of multi-frame images are instances of temporal stereo matching, we f…

2022

DetMatch: Two Teachers Are Better than One for Joint 2D and 3D Semi-Supervised Object Detection

ECCV 2022poster

"While numerous 3D detection works leverage the complementary relationship between RGB images and point clouds, developments in the broader framework of semi-supervised object recognition remain uninfluenced by multi-modal fusion. Current methods develop independent pipelines for 2D and 3D semi-supe…

2022

Image2Point: 3D Point-Cloud Understanding with 2D Image Pretrained Models

ECCV 2022poster

"3D point-clouds and 2D images are different visual representations of the physical world. While human vision can understand both representations, computer vision models designed for 2D image and 3D point-cloud understanding are quite different. Our paper explores the potential of transferring 2D mo…

2022

PreTraM: Self-Supervised Pre-training via Connecting Trajectory and Map

ECCV 2022poster

"Deep learning has recently achieved significant progress in trajectory forecasting. However, the scarcity of trajectory data inhibits the data-hungry deep-learning models from learning good representations. While pre-training methods for representation learning exist in computer vision and natural…

2021

A Simple and Efficient Multi-task Network for 3D Object Detection and Road Understanding

IROS 2021poster

Detecting dynamic objects and predicting static road information such as drivable areas and ground heights are crucial for safe autonomous driving. Previous works studied each perception task separately, and lacked a collective quantitative analysis. In this work, we show that it is possible to perf…

Cited by 28SourcecodeScholar
2021

Sparse R-CNN: End-to-End Object Detection With Learnable Proposals

CVPR 2021poster

We present Sparse R-CNN, a purely sparse method for object detection in images. Existing works on object detection heavily rely on dense object candidates, such as k anchor boxes pre-defined on all grids of image feature map of size HxW. In our method, however, a fixed sparse set of learned object p…

Cited by 1491PDFcodeScholar
2021

Visual Transformers: Where Do Transformers Really Belong in Vision Models?

ICCV 2021poster

A recent trend in computer vision is to replace convolutions with transformers. However, the performance gain of transformers is attained at a steep cost, requiring GPU years and hundreds of millions of samples for training. This excessive resource usage compensates for a misuse of transformers: Tra…

Cited by 32PDFScholar
2021

You Only Group Once: Efficient Point-Cloud Processing with Token Representation and Relation Inference Module

IROS 2021poster

3D perception on point-cloud is a challenging and crucial computer vision task. A point-cloud consists of a sparse, unstructured, and unordered set of points. To understand a point-cloud, previous point-based methods, such as PointNet++, extract visual features through the hierarchical aggregation o…

Cited by 28SourcecodeScholar
2020

SqueezeSegV3: Spatially-Adaptive Convolution for Efficient Point-Cloud Segmentation

ECCV 2020poster

LiDAR point-cloud segmentation is an important problem for many applications. For large-scale point cloud segmentation, the extit{de facto} method is to project a 3D point cloud to get a 2D LiDAR image and use convolutions to process it. Despite the similarity between regular RGB and LiDAR images, w…

2019

Learn to Scale: Generating Multipolar Normalized Density Maps for Crowd Counting

ICCV 2019poster

Dense crowd counting aims to predict thousands of human instances from an image, by calculating integrals of a density map over image pixels. Existing approaches mainly suffer from the extreme density variations. Such density pattern shift poses challenges even for multi-scale model ensembling. In t…

Cited by 144PDFScholar