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Li Niu

59 accepted papers

2026

Breaking Dual Bottlenecks: Evolving Unified Multimodal Models into Self-Adaptive Interleaved Visual Reasoners

ICML 2026poster

Recent unified models integrate multimodal understanding and generation within a single framework. However, an ``understanding-generation gap'' persists, where models can capture user intent but often fail to translate this semantic knowledge into precise pixel-level manipulation. This gap results i…

Cited by 0SourceScholar
2026

CareCom: Generative Image Composition with Calibrated Reference Features

AAAI 2026technical

Image composition aims to seamlessly insert foreground object into background. Despite the huge progress in generative image composition, the existing methods are still struggling with simultaneous detail preservation and foreground pose/view adjustment. To address this issue, we extend the existin

Cited by 0SourcePDFScholar
2026

D3ToM: Decider-Guided Dynamic Token Merging for Accelerating Diffusion MLLMs

AAAI 2026technical

Diffusion-based multimodal large language models (Diffusion MLLMs) have recently demonstrated impressive non-autoregressive generative capabilities across vision-and-language tasks. However, Diffusion MLLMs exhibit substantially slower inference than autoregressive models: Each denoising step employ

Cited by 0SourcePDFScholar
2026

Fine-Grained GRPO for Precise Preference Alignment in Flow Models

CVPR 2026

The incorporation of online reinforcement learning (RL) into diffusion and flow-based generative models has recently gained attention as a powerful paradigm for aligning model behavior with human preferences. By leveraging stochastic sampling via Stochastic Differential Equations (SDEs) during the d

Cited by 0SourcecodeScholar
2025

Decouple-Then-Merge: Finetune Diffusion Models as Multi-Task Learning

CVPR 2025poster

Diffusion models are trained by learning a sequence of models that reverse each step of noise corruption. Typically, the model parameters are fully shared across multiple timesteps to enhance training efficiency. However, since the denoising tasks differ at each timestep, the gradients computed at d…

Cited by 0SourcePDFScholar
2025

Divide and Conquer: Exploring Language-centric Tree Reasoning for Video Question-Answering

ICML 2025poster

Video Question-Answering (VideoQA) remains challenging in achieving advanced cognitive reasoning due to the uncontrollable and opaque reasoning processes in existing Multimodal Large Language Models (MLLMs). To address this issue, we propose a novel Language-centric Tree Reasoning (LTR) framework th…

Cited by 0SourcePDFScholar
2025

Pedestrian Motion Reconstruction: A Large-scale Benchmark via Mixed Reality Rendering with Multiple Perspectives and Modalities

ICLR 2025poster

Reconstructing pedestrian motion from dynamic sensors, with a focus on pedestrian intention, is crucial for advancing autonomous driving safety. However, this task is challenging due to data limitations arising from technical complexities, safety, and cost concerns. We introduce the Pedestrian Motio…

Cited by 0SourcePDFScholar
2025

Shadow Generation Using Diffusion Model with Geometry Prior

CVPR 2025poster

Image composition involves integrating foreground object into background image to obtain a composite image. One of the key challenges is to produce realistic shadow for the inserted foreground object. Recently, diffusion-based methods have shown superior performance compared to GAN-based methods in…

2025

The Devil is in the Prompts: Retrieval-Augmented Prompt Optimization for Text-to-Video Generation

CVPR 2025poster

The evolution of Text-to-video (T2V) generative models, trained on large-scale datasets, has been marked by significant progress. However, the sensitivity of T2V generative models to input prompts highlights the critical role of prompt design in influencing generative outcomes. Prior research has pr…

2025

Weak-shot Keypoint Estimation via Keyness and Correspondence Transfer

NeurIPS 2025poster

Keypoint estimation is a fundamental task in computer vision, but generally requires large-scale annotated data for training. Few-shot and unsupervised keypoint estimation are prevalent economical paradigms, but the former still requires annotations for extensive novel classes while the latter only…

Cited by 0SourceScholar
2024

Align and Aggregate: Compositional Reasoning with Video Alignment and Answer Aggregation for Video Question-Answering

CVPR 2024poster

Despite the recent progress made in Video Question-Answering (VideoQA) these methods typically function as black-boxes making it difficult to understand their reasoning processes and perform consistent compositional reasoning. To address these challenges we propose a model-agnostic Video Alignment a…

Cited by 4SourcePDFScholar
2024

DomainGallery: Few-shot Domain-driven Image Generation by Attribute-centric Finetuning

NeurIPS 2024poster

The recent progress in text-to-image models pretrained on large-scale datasets has enabled us to generate various images as long as we provide a text prompt describing what we want. Nevertheless, the availability of these models is still limited when we expect to generate images that fall into a spe…

2024

Meta-Point Learning and Refining for Category-Agnostic Pose Estimation

CVPR 2024poster

Category-agnostic pose estimation (CAPE) aims to predict keypoints for arbitrary classes given a few support images annotated with keypoints. Existing methods only rely on the features extracted at support keypoints to predict or refine the keypoints on query image but a few support feature vectors…

2024

Painterly Image Harmonization by Learning from Painterly Objects

AAAI 2024technical

Given a composite image with photographic object and painterly background, painterly image harmonization targets at stylizing the composite object to be compatible with the background. Despite the competitive performance of existing painterly harmonization works, they did not fully leverage the pain…

2024

Progressive Painterly Image Harmonization from Low-Level Styles to High-Level Styles

AAAI 2024technical

Painterly image harmonization aims to harmonize a photographic foreground object on the painterly background. Different from previous auto-encoder based harmonization networks, we develop a progressive multi-stage harmonization network, which harmonizes the composite foreground from low-level styles…

2024

Shadow Generation for Composite Image Using Diffusion Model

CVPR 2024poster

In the realm of image composition generating realistic shadow for the inserted foreground remains a formidable challenge. Previous works have developed image-to-image translation models which are trained on paired training data. However they are struggling to generate shadows with accurate shapes an…

2024

Shadow Generation with Decomposed Mask Prediction and Attentive Shadow Filling

AAAI 2024technical

Image composition refers to inserting a foreground object into a background image to obtain a composite image. In this work, we focus on generating plausible shadows for the inserted foreground object to make the composite image more realistic. To supplement the existing small-scale dataset, we crea…

2024

WeditGAN: Few-Shot Image Generation via Latent Space Relocation

AAAI 2024technical

In few-shot image generation, directly training GAN models on just a handful of images faces the risk of overfitting. A popular solution is to transfer the models pretrained on large source domains to small target ones. In this work, we introduce WeditGAN, which realizes model transfer by editing th…

2023

Amodal Instance Segmentation via Prior-Guided Expansion

AAAI 2023technical

Amodal instance segmentation aims to infer the amodal mask, including both the visible part and occluded part of each object instance. Predicting the occluded parts is challenging. Existing methods often produce incomplete amodal boxes and amodal masks, probably due to lacking visual evidences to ex…

Cited by 9SourcePDFScholar
2023

Deep Image Harmonization with Globally Guided Feature Transformation and Relation Distillation

ICCV 2023poster

Given a composite image, image harmonization aims to adjust the foreground illumination to be consistent with background. Previous methods have explored transforming foreground features to achieve competitive performance. In this work, we show that using global information to guide foreground featur…

Cited by 12PDFcodeScholar
2023

Few-Shot Defect Image Generation via Defect-Aware Feature Manipulation

AAAI 2023technical

The performances of defect inspection have been severely hindered by insufficient defect images in industries, which can be alleviated by generating more samples as data augmentation. We propose the first defect image generation method in the challenging few-shot cases. Given just a handful of defec…

2023

Geometric Inductive Biases for Identifiable Unsupervised Learning of Disentangled Representations

AAAI 2023technical

The model identifiability is a considerable issue in the unsupervised learning of disentangled representations. The PCA inductive biases revealed recently for unsupervised disentangling in VAE-based models are shown to improve local alignment of latent dimensions with principal components of the dat…

2022

Deep Video Harmonization With Color Mapping Consistency

IJCAI 2022poster

Video harmonization aims to adjust the foreground of a composite video to make it compatible with the background. So far, video harmonization has only received limited attention and there is no public dataset for video harmonization. In this work, we construct a new video harmonization dataset HYouT…

2022

DeltaGAN: Towards Diverse Few-Shot Image Generation with Sample-Specific Delta

ECCV 2022poster

"Learning to generate new images for a novel category based on only a few images, named as few-shot image generation, has attracted increasing research interest. Several state-of-the-art works have yielded impressive results, but the diversity is still limited. In this work, we propose a novel Delta…

2022

From Representation to Reasoning: Towards Both Evidence and Commonsense Reasoning for Video Question-Answering

CVPR 2022poster

Video understanding has achieved great success in representation learning, such as video caption, video object grounding, and video descriptive question-answer. However, current methods still struggle on video reasoning, including evidence reasoning and commonsense reasoning. To facilitate deeper vi…

Cited by 69PDFcodeScholar
2022

High-Resolution Image Harmonization via Collaborative Dual Transformations

CVPR 2022poster

Given a composite image, image harmonization aims to adjust the foreground to make it compatible with the background. High-resolution image harmonization is in high demand, but still remains unexplored. Conventional image harmonization methods learn global RGB-to-RGB transformation which could effor…

Cited by 101PDFcodeScholar
2022

Human-Centric Image Cropping with Partition-Aware and Content-Preserving Features

ECCV 2022poster

"Image cropping aims to find visually appealing crops in an image, which is an important yet challenging task. In this paper, we consider a specific and practical application: human-centric image cropping, which focuses on the depiction of a person. To this end, we propose a human-centric image crop…

2022

Inharmonious Region Localization by Magnifying Domain Discrepancy

AAAI 2022technical

Inharmonious region localization aims to localize the region in a synthetic image which is incompatible with surrounding background. The inharmony issue is mainly attributed to the color and illumination inconsistency produced by image editing techniques. In this work, we tend to transform the input…

2022

Weak-shot Semantic Segmentation via Dual Similarity Transfer

NeurIPS 2022accept

Semantic segmentation is a practical and active task, but severely suffers from the expensive cost of pixel-level labels when extending to more classes in wider applications. To this end, we focus on the problem named weak-shot semantic segmentation, where the novel classes are learnt from cheaper i…

2021

Activity Image-to-Video Retrieval by Disentangling Appearance and Motion

AAAI 2021technical

With the rapid emergence of video data, image-to-video retrieval has attracted much attention. There are two types of image-to-video retrieval: instance-based and activity-based. The former task aims to retrieve videos containing the same main objects as the query image, while the latter focuses on…

Cited by 26SourcePDFScholar
2021

Depth Privileged Object Detection in Indoor Scenes via Deformation Hallucination

AAAI 2021technical

RGB-D object detection has achieved significant advance, because depth provides complementary geometric information to RGB images. Considering depth images are unavailable in some scenarios, we focus on depth privileged object detection in indoor scenes, where the depth images are only available in…

Cited by 7SourcePDFScholar
2021

Mixed Supervised Object Detection by Transferring Mask Prior and Semantic Similarity

NeurIPS 2021poster

Object detection has achieved promising success, but requires large-scale fully-annotated data, which is time-consuming and labor-extensive. Therefore, we consider object detection with mixed supervision, which learns novel object categories using weak annotations with the help of full annotations o…

2021

Parallel Multi-Resolution Fusion Network for Image Inpainting

ICCV 2021poster

Conventional deep image inpainting methods are based on auto-encoder architecture, in which the spatial details of images will be lost in the down-sampling process, leading to the degradation of generated results. Also, the structure information in deep layers and texture information in shallow laye…

Cited by 39PDFScholar
2021

Weak-shot Fine-grained Classification via Similarity Transfer

NeurIPS 2021poster

Recognizing fine-grained categories remains a challenging task, due to the subtle distinctions among different subordinate categories, which results in the need of abundant annotated samples. To alleviate the data-hungry problem, we consider the problem of learning novel categories from web data wit…

2020

DoveNet: Deep Image Harmonization via Domain Verification

CVPR 2020poster

Image composition is an important operation in image processing, but the inconsistency between foreground and background significantly degrades the quality of composite image. Image harmonization, aiming to make the foreground compatible with the background, is a promising yet challenging task. Howe…

Cited by 260PDFcodeScholar
2018

Learning From Noisy Web Data With Category-Level Supervision

CVPR 2018poster

Learning from web data is increasingly popular due to abundant free web resources. However, the performance gap between webly supervised learning and traditional supervised learning is still very large, due to the label noise of web data. To fill this gap, most existing methods propose to purify or…

Cited by 34SourcePDFScholar
2018

Look, Imagine and Match: Improving Textual-Visual Cross-Modal Retrieval With Generative Models

CVPR 2018poster

Textual-visual cross-modal retrieval has been a hot research topic in both computer vision and natural language processing communities. Learning appropriate representations for multi-modal data is crucial for the cross-modal retrieval performance. Unlike existing image-text retrieval approaches that…

Cited by 476SourcePDFScholar
2018

Webly Supervised Learning Meets Zero-Shot Learning: A Hybrid Approach for Fine-Grained Classification

CVPR 2018poster

Fine-grained image classification, which targets at distinguishing subtle distinctions among various subordinate categories, remains a very difficult task due to the high annotation cost of enormous fine-grained categories. To cope with the scarcity of well-labeled training images, existing works ma…

Cited by 96SourcePDFScholar
2015

Visual Recognition by Learning From Web Data: A Weakly Supervised Domain Generalization Approach

CVPR 2015poster

In this work, we formulate a new weakly supervised domain generalization problem for the visual recognition task by using loosely labeled web images/videos as training data. Specifically, we aim to address two challenging issues when learning robust classifiers: 1) enhancing the generalization capab…

Cited by 94SourcePDFScholar