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Sifei Liu

67 accepted papers

2026

3D Aware Region Prompted Vision Language Model

ICLR 2026poster

We present Spatial Region 3D (SR-3D) aware vision-language model that connects single-view 2D images and multi-view 3D data through a shared visual token space. SR-3D supports flexible region prompting, allowing users to annotate regions with bounding boxes, segmentation masks on any frame, or direc…

Cited by 0SourcecodeScholar
2026

4D-RGPT: Toward Region-level 4D Understanding via Perceptual Distillation

CVPR 2026

Despite advances in Multimodal LLMs (MLLMs), their ability to reason over 3D structures and temporal dynamics remains limited, constrained by weak 4D perception and temporal understanding. Existing 3D and 4D Video Question Answering (VQA) benchmarks also emphasize static scenes and lack region-level

Cited by 0SourcecodeScholar
2026

4DP-QA: Scalable QA for 4D Perception in Vision Language Models

CVPR 2026

Despite recent advances, Vision Language Models (VLMs) still struggle to grasp the dynamics of the world. We note that the ability to reason about a 4D scene, challenging in itself, is further complicated by two factors. First, VLMs observe motion indirectly via its projection onto 2D images. Second

Cited by 0SourceScholar
2026

OmniVinci: Enhancing Architecture and Data for Omni-Modal Understanding LLM

ICLR 2026poster

Advancing machine intelligence requires developing the ability to perceive across multiple modalities, much as humans sense the world. We introduce OmniVinci, an initiative to build a strong, open-source, omni-modal LLM. We carefully study the design choices across model architecture and data curati…

Cited by 0SourcecodeScholar
2026

QeRL: Beyond Efficiency - Quantization-enhanced Reinforcement Learning for LLMs

ICLR 2026poster

We propose QeRL, a Quantization-enhanced Reinforcement Learning framework for large language models (LLMs). While RL is essential for LLMs' reasoning capabilities, it is resource-intensive, requiring substantial GPU memory and long rollout duration. QeRL addresses these issues by combining NVFP4 qua…

Cited by 0SourcecodeScholar
2026

Scaling Parallel Sequence Models to Vision Foundation Models

CVPR 2026

Scaling vision foundation models is constrained by the quadratic complexity of self-attention. Although subquadratic attention alternatives like linear attention variants and state-space models successfully reduce the model complexity, they typically serialize images into 1D token sequences, comprom

Cited by 0SourceScholar
2025

BlobGEN-Vid: Compositional Text-to-Video Generation with Blob Video Representations

CVPR 2025poster

Existing video generation models struggle to follow complex text prompts and synthesize multiple objects, raising the need for additional grounding input for improved controllability. In this work, we propose to decompose videos into visual primitives -- blob video representation, a general represen…

Cited by 3SourcePDFScholar
2025

Describe Anything: Detailed Localized Image and Video Captioning

ICCV 2025poster

Generating detailed and accurate descriptions for specific regions in images and videos remains a fundamental challenge for vision-language models. We introduce the Describe Anything Model (DAM), a model designed for detailed localized captioning (DLC). DAM preserves both local details and global co…

Cited by 0SourcePDFScholar
2025

GSPN-2: Efficient Parallel Sequence Modeling

NeurIPS 2025poster

Efficient vision transformer remains a bottleneck for high-resolution images and long-video related real-world applications. Generalized Spatial Propagation Network (GSPN) \cite{wang2025parallel} addresses this by replacing quadratic self-attention with a line-scan propagation scheme, bringing the c…

Cited by 0SourceScholar
2025

NVILA: Efficient Frontier Visual Language Models

CVPR 2025poster

Visual language models (VLMs) have made significant advances in accuracy in recent years. However, their efficiency has received much less attention. This paper introduces NVILA, a family of open VLMs designed to optimize both efficiency and accuracy. Building on top of VILA, we improve its model ar…

Cited by 43SourcePDFScholar
2025

NaVILA: Legged Robot Vision-Language-Action Model for Navigation

RSS 2025poster

This paper proposes to solve the problem of Vision-and-Language Navigation with legged robots, which not only provides a flexible way for humans to command but also allows the robot to navigate through more challenging and cluttered scenes. However, it is non-trivial to translate human language inst…

Cited by 13PDFScholar
2025

No Pose, No Problem: Surprisingly Simple 3D Gaussian Splats from Sparse Unposed Images

ICLR 2025oral

We introduce NoPoSplat, a feed-forward model capable of reconstructing 3D scenes parameterized by 3D Gaussians from unposed sparse multi-view images. Our model, trained exclusively with photometric loss, achieves real-time 3D Gaussian reconstruction during inference. To eliminate the need for accura…

2025

Omni-RGPT: Unifying Image and Video Region-level Understanding via Token Marks

CVPR 2025poster

We present Omni-RGPT, a multimodal large language model designed to facilitate region-level comprehension for both images and videos. To achieve consistent region representation across spatio-temporal dimensions, we introduce Token Mark, a set of tokens highlighting the target regions within the vis…

Cited by 2SourcePDFScholar
2025

Parallel Sequence Modeling via Generalized Spatial Propagation Network

CVPR 2025poster

We present the Generalized Spatial Propagation Network (GSPN), a new attention mechanism optimized for vision tasks that inherently captures 2D spatial structures. Existing attention models, including transformers, linear attention, and state-space models like Mamba, process multi-dimensional data a…

Cited by 0SourcePDFScholar
2025

Scaling Vision Pre-Training to 4K Resolution

CVPR 2025highlight

High-resolution perception of visual details is crucial for daily tasks. Current vision pre-training, however, is still limited to low resolutions (e.g., 378 x 378 pixels) due to the quadratic cost of processing larger images. We introduce PS3 that scales CLIP-style vision pre-training to 4K resolut…

Cited by 0SourcePDFScholar
2025

Token-Efficient VLM: High-Resolution Image Understanding via Dynamic Region Proposal

ICCV 2025poster

Vision-Language Models (VLMs) excel at visual understanding by leveraging pretrained image encoders to generate visual tokens. However, they struggle with high-resolution images and zoomed-in regions due to the computational burden and token redundancy of uniform patch-based processing, often leadin…

Cited by 0SourcePDFScholar
2024

3D Reconstruction with Generalizable Neural Fields using Scene Priors

ICLR 2024poster

High-fidelity 3D scene reconstruction has been substantially advanced by recent progress in neural fields. However, most existing methods train a separate network from scratch for each individual scene. This is not scalable, inefficient, and unable to yield good results given limited views. While le…

2024

A Unified Approach for Text- and Image-guided 4D Scene Generation

CVPR 2024poster

Large-scale diffusion generative models are greatly simplifying image video and 3D asset creation from user provided text prompts and images. However the challenging problem of text-to-4D dynamic 3D scene generation with diffusion guidance remains largely unexplored. We propose Dream-in-4D which fea…

Cited by 51SourcePDFScholar
2024

COLMAP-Free 3D Gaussian Splatting

CVPR 2024highlight

While neural rendering has led to impressive advances in scene reconstruction and novel view synthesis it relies heavily on accurately pre-computed camera poses. To relax this constraint multiple efforts have been made to train Neural Radiance Fields (NeRFs) without pre-processed camera poses. Howev…

2024

Communication-Efficient Collaborative Perception via Information Filling with Codebook

CVPR 2024poster

Collaborative perception empowers each agent to improve its perceptual ability through the exchange of perceptual messages with other agents. It inherently results in a fundamental trade-off between perception ability and communication cost. To address this bottleneck issue our core idea is to optim…

2024

Compositional Text-to-Image Generation with Dense Blob Representations

ICML 2024poster

Existing text-to-image models struggle to follow complex text prompts, raising the need for extra grounding inputs for better controllability. In this work, we propose to decompose a scene into visual primitives - denoted as dense blob representations - that contain fine-grained details of the scene…

Cited by 16SourcePDFScholar
2024

HOIDiffusion: Generating Realistic 3D Hand-Object Interaction Data

CVPR 2024poster

3D hand-object interaction data is scarce due to the hardware constraints in scaling up the data collection process. In this paper we propose HOIDiffusion for generating realistic and diverse 3D hand-object interaction data. Our model is a conditional diffusion model that takes both the 3D hand-obje…

2024

RGBD Objects in the Wild: Scaling Real-World 3D Object Learning from RGB-D Videos

CVPR 2024poster

We introduce a new RGB-D object dataset captured in the wild called WildRGB-D. Unlike most existing real-world object-centric datasets which only come with RGB capturing the direct capture of the depth channel allows better 3D annotations and broader downstream applications. WildRGB-D comprises larg…

2024

RegionGPT: Towards Region Understanding Vision Language Model

CVPR 2024poster

Vision language models (VLMs) have experienced rapid advancements through the integration of large language models (LLMs) with image-text pairs yet they struggle with detailed regional visual understanding due to limited spatial awareness of the vision encoder and the use of coarse-grained training…

Cited by 44SourcePDFScholar
2024

SpatialRGPT: Grounded Spatial Reasoning in Vision-Language Models

NeurIPS 2024poster

Vision Language Models (VLMs) have demonstrated remarkable performance in 2D vision and language tasks. However, their ability to reason about spatial arrangements remains limited. In this work, we introduce Spatial Region GPT (SpatialRGPT) to enhance VLMs’ spatial perception and reasoning capabilit…

Cited by 61SourcePDFScholar
2023

Affordance Diffusion: Synthesizing Hand-Object Interactions

CVPR 2023poster

Recent successes in image synthesis are powered by large-scale diffusion models. However, most methods are currently limited to either text- or image-conditioned generation for synthesizing an entire image, texture transfer or inserting objects into a user-specified region. In contrast, in this work…

2023

Generalizable One-shot 3D Neural Head Avatar

NeurIPS 2023poster

We present a method that reconstructs and animates a 3D head avatar from a single-view portrait image. Existing methods either involve time-consuming optimization for a specific person with multiple images, or they struggle to synthesize intricate appearance details beyond the facial region. To addr…

Cited by 31SourcePDFScholar
2023

Open-Vocabulary Panoptic Segmentation With Text-to-Image Diffusion Models

CVPR 2023highlight

We present ODISE: Open-vocabulary DIffusion-based panoptic SEgmentation, which unifies pre-trained text-image diffusion and discriminative models to perform open-vocabulary panoptic segmentation. Text-to-image diffusion models have the remarkable ability to generate high-quality images with diverse…

2023

Self-Supervised Super-Plane for Neural 3D Reconstruction

CVPR 2023poster

Neural implicit surface representation methods show impressive reconstruction results but struggle to handle texture-less planar regions that widely exist in indoor scenes. Existing approaches addressing this leverage image prior that requires assistive networks trained with large-scale annotated da…

2023

Zero-Shot Pose Transfer for Unrigged Stylized 3D Characters

CVPR 2023poster

Transferring the pose of a reference avatar to stylized 3D characters of various shapes is a fundamental task in computer graphics. Existing methods either require the stylized characters to be rigged, or they use the stylized character in the desired pose as ground truth at training. We present a z…

2022

Autoregressive 3D Shape Generation via Canonical Mapping

ECCV 2022poster

"With the capacity of modeling long-range dependencies in sequential data, transformers have shown remarkable performances in a variety of generative tasks such as image, audio, and text generation. Yet, taming them in generating less structured and voluminous data formats such as high-resolution po…

2022

CoordGAN: Self-Supervised Dense Correspondences Emerge From GANs

CVPR 2022poster

Recent advances show that Generative Adversarial Networks (GANs) can synthesize images with smooth variations along semantically meaningful latent directions, such as pose, expression, layout, etc. While this indicates that GANs implicitly learn pixel-level correspondences across images, few studies…

Cited by 22PDFcodeScholar
2022

GroupViT: Semantic Segmentation Emerges From Text Supervision

CVPR 2022poster

Grouping and recognition are important components of visual scene understanding, e.g., for object detection and semantic segmentation. With end-to-end deep learning systems, grouping of image regions usually happens implicitly via top-down supervision from pixel-level recognition labels. Instead, in…

Cited by 612PDFcodeScholar
2022

Learning Continuous Environment Fields via Implicit Functions

ICLR 2022poster

We propose a novel scene representation that encodes reaching distance -- the distance between any position in the scene to a goal along a feasible trajectory. We demonstrate that this environment field representation can directly guide the dynamic behaviors of agents in 2D mazes or 3D indoor scenes…

Cited by 12SourcePDFScholar
2022

Scraping Textures from Natural Images for Synthesis and Editing

ECCV 2022poster

"Existing texture synthesis methods focus on generating large texture images given a small texture sample. But such samples are typically assumed to be highly curated: rectangular, clean, and stationary. This paper aims to scrape textures directly from natural images of everyday objects and scenes,…

Cited by 4SourcePDFScholar
2021

Contrastive Syn-to-Real Generalization

ICLR 2021poster

Training on synthetic data can be beneficial for label or data-scarce scenarios. However, synthetically trained models often suffer from poor generalization in real domains due to domain gaps. In this work, we make a key observation that the diversity of the learned feature embeddings plays an impor…

2021

Coupled Segmentation and Edge Learning via Dynamic Graph Propagation

NeurIPS 2021poster

Image segmentation and edge detection are both central problems in perceptual grouping. It is therefore interesting to study how these two tasks can be coupled to benefit each other. Indeed, segmentation can be easily transformed into contour edges to guide edge learning. However, the converse is no…

Cited by 14SourcePDFScholar
2021

Learning 3D Dense Correspondence via Canonical Point Autoencoder

NeurIPS 2021poster

We propose a canonical point autoencoder (CPAE) that predicts dense correspondences between 3D shapes of the same category. The autoencoder performs two key functions: (a) encoding an arbitrarily ordered point cloud to a canonical primitive, e.g., a sphere, and (b) decoding the primitive back to the…

Cited by 28SourcePDFScholar
2021

Learning to Track Instances without Video Annotations

CVPR 2021poster

Tracking segmentation masks of multiple instances has been intensively studied, but still faces two fundamental challenges: 1) the requirement of large-scale, frame-wise annotation, and 2) the complexity of two-stage approaches. To resolve these challenges, we introduce a novel semi-supervised frame…

Cited by 32PDFScholar
2021

Self-Supervised Object Detection via Generative Image Synthesis

ICCV 2021poster

We present SSOD -- the first end-to-end analysis-by-synthesis framework with controllable GANs for the task of self-supervised object detection. We use collections of real-world images without bounding box annotations to learn to synthesize and detect objects. We leverage controllable GANs to synthe…

Cited by 15PDFcodeScholar
2021

Semi-Supervised 3D Hand-Object Poses Estimation With Interactions in Time

CVPR 2021poster

Estimating 3D hand and object pose from a single image is an extremely challenging problem: hands and objects are often self-occluded during interactions, and the 3D annotations are scarce as even humans cannot directly label the ground-truths from a single image perfectly. To tackle these challenge…

Cited by 195PDFcodeScholar
2021

Synthesizing Long-Term 3D Human Motion and Interaction in 3D Scenes

CVPR 2021poster

Synthesizing 3D human motion plays an important role in many graphics applications as well as understanding human activity. While many efforts have been made on generating realistic and natural human motion, most approaches neglect the importance of modeling human-scene interactions and affordances.…

Cited by 145PDFScholar
2021

Video Autoencoder: Self-Supervised Disentanglement of Static 3D Structure and Motion

ICCV 2021poster

We present Video Autoencoder for learning disentangled representations of 3D structure and camera pose from videos in a self-supervised manner. Relying on temporal continuity in videos, our work assumes that the 3D scene structure in nearby video frames remains static. Given a sequence of video fram…

Cited by 39PDFScholar
2021

Video Matting via Consistency-Regularized Graph Neural Networks

ICCV 2021poster

Learning temporally consistent foreground opacity from videos, i.e., video matting, has drawn great attention due to the blossoming of video conferencing. Previous approaches are built on top of image matting models, which fail in maintaining the temporal coherence when being adapted to videos. They…

Cited by 32PDFcodeScholar
2020

Online Adaptation for Consistent Mesh Reconstruction in the Wild

NeurIPS 2020poster

This paper presents an algorithm to reconstruct temporally consistent 3D meshes of deformable object instances from videos in the wild. Without requiring annotations of 3D mesh, 2D keypoints, or camera pose for each video frame, we pose video-based reconstruction as a self-supervised online adaptati…

Cited by 61SourcePDFScholar
2020

Self-Supervised Viewpoint Learning From Image Collections

CVPR 2020poster

Training deep neural networks to estimate the viewpoint of objects requires large labeled training datasets. However, manually labeling viewpoints is notoriously hard, error-prone, and time-consuming. On the other hand, it is relatively easy to mine many unlabeled images of an object category from t…

Cited by 45PDFcodeScholar
2020

Self-supervised Single-view 3D Reconstruction via Semantic Consistency

ECCV 2020poster

We learn a self-supervised, single-view 3D reconstruction model that predicts the 3D mesh shape, texture and camera pose of a target object with a collection of 2D images and silhouettes. The proposed method does not necessitate 3D supervision, manually annotated keypoints, multi-view images of an o…

Cited by 200SourcePDFScholar
2019

Joint-task Self-supervised Learning for Temporal Correspondence

NeurIPS 2019poster

This paper proposes to learn reliable dense correspondence from videos in a self-supervised manner. Our learning process integrates two highly related tasks: tracking large image regions and establishing fine-grained pixel-level associations between consecutive video frames. We exploit the synergy b…

2019

Learning Linear Transformations for Fast Image and Video Style Transfer

CVPR 2019poster

Given a random pair of images, a universal style transfer method extracts the feel from a reference image to synthesize an output based on the look of a content image. Recent algorithms based on second-order statistics, however, are either computationally expensive or prone to generate artifacts due…

Cited by 291PDFScholar
2019

Putting Humans in a Scene: Learning Affordance in 3D Indoor Environments

CVPR 2019poster

Affordance modeling plays an important role in visual understanding. In this paper, we aim to predict affordances of 3D indoor scenes, specifically what human poses are afforded by a given indoor environment, such as sitting on a chair or standing on the floor. In order to predict valid affordances…

Cited by 125PDFScholar
2019

SCOPS: Self-Supervised Co-Part Segmentation

CVPR 2019poster

Parts provide a good intermediate representation of objects that is robust with respect to camera, pose and appearance variations. Existing work on part segmentation is dominated by supervised approaches that rely on large amounts of manual annotations and also can not generalize to unseen object ca…

Cited by 178PDFScholar
2018

Context-aware Synthesis and Placement of Object Instances

NeurIPS 2018poster

Learning to insert an object instance into an image in a semantically coherent manner is a challenging and interesting problem. Solving it requires (a) determining a location to place an object in the scene and (b) determining its appearance at the location. Such an object insertion model can potent…

2018

Learning Dual Convolutional Neural Networks for Low-Level Vision

CVPR 2018poster

In this paper, we propose a general dual convolutional neural network (DualCNN) for low-level vision problems, e.g., super-resolution, edge-preserving filtering, deraining and dehazing. These problems usually involve the estimation of two components of the target signals: structures and details. Mot…

Cited by 230SourcePDFScholar
2018

Rendering Portraitures from Monocular Camera and Beyond

ECCV 2018poster

Shallow Depth-of-Field (DoF) is a desirable effect in photography which renders artistic photos. Usually, it requires single-lens reflex cameras and certain photography skills to generate such effects. Recently, dual-lens on cellphones is used to estimate scene depth and simulate DoF effects for por…

Cited by 32SourcePDFScholar
2018

Switchable Temporal Propagation Network

ECCV 2018poster

Videos contain highly redundant information between frames. Such redundancy has been studied extensively in video compression and encoding but is less explored for more advanced video processing. In this paper, we propose a learnable unified framework for propagating a variety of visual properties o…

Cited by 49SourcePDFScholar
2017

Learning Affinity via Spatial Propagation Networks

NeurIPS 2017poster

In this paper, we propose a spatial propagation networks for learning affinity matrix. We show that by constructing a row/column linear propagation model, the spatially variant transformation matrix constitutes an affinity matrix that models dense, global pairwise similarities of an image. Specifica…

Cited by 338SourcePDFScholar
2017

Unsupervised Domain Adaptation for Face Recognition in Unlabeled Videos

ICCV 2017poster

Despite rapid advances in face recognition, there remains a clear gap between the performance of still image-based face recognition and video-based face recognition, due to the vast difference in visual quality between the domains and the difficulty of curating diverse large-scale video datasets. Th…

Cited by 147PDFScholar