EDBT 2026 Demo / reviewers in the wild / expert
Ka Chun Cheung
dblp:165/1089
· DBLP profile ↗
37ranked-venue papers
1as first author
36since 2021 · last 2026
0000-0002-2939-4686ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 28 · 27 since 2021Graphics, computer vision, multimedia, augmented reality and games · 26 · 25 since 2021Applied, interdisciplinary, general and emerging computing · 2 · 2 since 2021Systems, architecture and hardware · 1 · 1 first-author · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Cross-domain Few-shot Classification via Invariant-content Feature ReconstructionabstractAbstract In cross-domain few-shot classification (CFC), mainstream studies aim to train a simple module (e.g. a linear transformation head) to select or transform features (a.k.a., the high-level semantic features) for previously unseen domains with a few labeled training data available on top of a powerful pre-trained model. These studies usually assume that high-level semantic features are shared across these domains, and just simple feature selection or transformations are enough to adapt features to previously unseen domains. However, in this paper, we find that the simply transformed features are too general to fully cover the key content features regarding each class. Thus, we propose an effective method, invariant-content feature reconstruction (IFR), to train a simple module that simultaneously considers both high-level and fine-grained invariant-content features for the previously unseen domains. Specifically, the fine-grained invariant-content features are considered as a set of informative and discriminative features learned from a few labeled training data of tasks sampled from unseen domains and are extracted by retrieving features that are invariant to style modifications from a set of content-preserving augmented data in pixel level with an attention module. Extensive experiments on the Meta-Dataset benchmark show that IFR achieves good generalization performance on unseen domains, which demonstrates the effectiveness of the fusion of the high-level features and the fine-grained invariant-content features. Specifically, IFR improves the average accuracy on unseen domains by 1.6% and 6.5% respectively under two different cross-domain few-shot classification settings. Hongduan Tian, Feng Liu 0003, Ka Chun Cheung, Zhen Fang 0001, Simon See, Tongliang Liu, Bo Han 0003 |
Int. J. Comput. Vis. | 3 |
| 2025 | M3Net: Multimodal Multi-task Learning for 3D Detection, Segmentation, and Occupancy Prediction in Autonomous DrivingabstractThe perception system for autonomous driving generally requires to handle multiple diverse sub-tasks. However, current algorithms typically tackle individual sub-tasks separately, which leads to low efficiency when aiming at obtaining full-perception results. Some multi-task learning methods try to unify multiple tasks with one model, but do not solve the conflicts in multi-task learning. In this paper, we introduce M3Net, a novel multimodal and multi-task network that simultaneously tackles detection, segmentation, and 3D occupancy prediction for autonomous driving and achieves superior performance than single task model. M3Net takes multimodal data as input and multiple tasks via query-token interactions. To enhance the integration of multi-modal features for multi-task learning, we first propose the Modality-Adaptive Feature Integration (MAFI) module, which enables single-modality features to predict channel-wise attention weights for their high-performing tasks, respectively. Based on integrated features, we then develop task-specific query initialization strategies to accommodate the needs of detection/segmentation and 3D occupancy prediction. Leveraging the properly initialized queries, a shared decoder transforms queries and BEV features layer-wise, facilitating multi-task learning. Furthermore, we propose a Task-oriented Channel Scaling (TCS) module in the decoder to mitigate conflicts between optimizing for different tasks. Additionally, our proposed multi-task querying and TCS module support both Transformer-based decoder and Mamba-based decoder, demonstrating its flexibility to different architectures. M3Net achieves state-of-the-art multi-task learning performance on the nuScenes benchmarks. Xuesong Chen 0001, Shaoshuai Shi, Tao Ma 0002, Jingqiu Zhou, Simon See, Ka Chun Cheung, Hongsheng Li 0001 |
AAAI | 6 |
| 2025 | Test-Time Adaptation on Noisy Data via Model-Pruning-Based Filtering and Flatness-Aware Entropy MinimizationabstractTest-time adaptation (TTA) deals with domain shifts during inference by training models based on only unlabeled test samples. Test samples may include noisy samples, which degrade domain adaptation. Existing methods rely on the model's output prediction to detect and filter noisy samples, and further search for flat regions during optimization, which makes the optimization more robust on noisy samples. However, there are two issues: (1) the output prediction tends to be inaccurate due to domain shifts, weakening noisy-sample detection; (2) current approaches for searching flat regions focus on optimization to enhance the worst case, which ignores achieving flatness by avoiding the quick changing of losses. To address these challenges, we propose a model pruning-based test-time adaptation model for noisy data streams, named MoTTA, which leverages a new proposed filtering, output difference under pruning (ODP)-based filtering, and a flatness-aware entropy minimization (FlatEM). Specifically, to reduce the impact of inaccurate output predictions, ODP-based filtering measures the output difference of a sample before and after model pruning, which works even under inaccurate output. To improve the search for flat loss surfaces, FlatEM integrates zeroth-order flatness and first-order flatness (minimize the maximal gradient normalization with a weight perturbation constrained in a small Euclidean ball) on entropy minimization. To solve these hard maximum problems, we leverage Taylor expansion to obtain approximated results for optimization. FlatEM also adopts a parameter regularization to mitigate incorrect updates from noisy samples. The experiments show our advantages in dealing with noisy data streams at TTA comparable to existing baselines. Xingzhi Zhou 0002, Zhiliang Tian, Ka Chun Cheung, Simon See, Nevin Lianwen Zhang |
AAAI | 5 |
| 2025 | Meme Trojan: Backdoor Attacks Against Hateful Meme Detection via Cross-Modal TriggersabstractHateful meme detection aims to prevent the proliferation of hateful memes on various social media platforms. Considering its impact on social environments, this paper introduces a previously ignored but significant threat to hateful meme detection: backdoor attacks. By injecting specific triggers into meme samples, backdoor attackers can manipulate the detector to output their desired outcomes. To explore this, we propose the Meme Trojan framework to initiate backdoor attacks on hateful meme detection. Meme Trojan involves creating a novel Cross-Modal Trigger (CMT) and a learnable trigger augmentor to enhance the trigger pattern according to each input sample. Due to the cross-modal property, the proposed CMT can effectively initiate backdoor attacks on hateful meme detectors under an automatic application scenario. Additionally, the injection position and size of our triggers are adaptive to the texts contained in the meme, which ensures that the trigger is seamlessly integrated with the meme content. Our approach outperforms the state-of-the-art backdoor attack methods, showing significant improvements in effectiveness and stealthiness. We believe that this paper will draw more attention to the potential threat posed by backdoor attacks on hateful meme detection. Ruofei Wang, Hongzhan Lin 0001, Ziyuan Luo, Ka Chun Cheung, Simon See, Jing Ma 0004, Renjie Wan |
AAAI | 4 |
| 2025 | One-Minute Video Generation with Test-Time TrainingabstractTransformers today still struggle to generate one-minute videos because self-attention layers are inefficient for long context. Alternatives such as Mamba layers struggle to produce coherent scenes because their hidden states are small and less expressive. We experiment with Test-Time Training (TTT) layers, whose hidden states themselves can be neural networks, therefore larger and more expressive. Adding TTT layers into a pre-trained Transformer enables it to generate one-minute videos from text storyboards. We curate a dataset based on Tom and Jerry cartoons as a proof-of-concept benchmark. Compared to baselines such as Mamba 2, Gated DeltaNet, and sliding-window attention layers, TTT layers generate much more coherent videos that tell complete stories, leading by 34 Elo points in a human evaluation of 100 videos per method. Although promising, our results are still limited in physical realism, and the efficiency of our implementation can be further improved.Sample videos, code and annotations are available at: https://test-time-training.github.io/video-dit Karan Dalal, Daniel Koceja, Yue Zhao 0006, Shihao Han, Ka Chun Cheung, Jan Kautz, Yejin Choi 0001, Yu Sun 0020, Xiaolong Wang 0004 |
CVPR | 6 |
| 2025 | Parallel Sequence Modeling via Generalized Spatial Propagation NetworkabstractWe 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 multidimensional data as 1D sequences, compromising spatial coherence and efficiency. GSPN overcomes these limitations by directly operating on spatially coherent image data and forming dense pairwise connections through a line-scan approach. Central to GSPN is the Stability-Context Condition, which ensures stable, long-context propagation across 2D sequences and reduces the effective sequence length to $\sqrt N $ for a square map with N elements, which significantly enhances computational efficiency. With learnable, input-dependent weights and no reliance on positional embeddings, GSPN achieves superior spatial fidelity and state-of-the-art performance in vision tasks, including ImageNet classification, class-guided image generation, and text-to-image generation. Notably, GSPN accelerates SD-XL with softmax-attention by over 84× when generating 16K images. Project page: https://whj363636.github.io/GSPN/ Wonmin Byeon, Jinwei Gu, Ka Chun Cheung, Xiaolong Wang 0004, Kai Han 0001, Jan Kautz, Sifei Liu |
CVPR | 5 |
| 2025 | Resilient Test-Time Adaptation by Mitigating Batch-Normalization OverfittingabstractTest-time domain adaptation adjusts a source domain model to accommodate previously unseen domain shifts in a target domain during inference. In real-world scenarios, domain shifts continually evolve, and test data are often non-independent and identically distributed (non-i.i.d.). Existing methods update batch normalization (BN) statistics (mean and variance) based on test batch statistics to mitigate domain shifts and use a memory bank to provide approximate i.i.d. sampling by selectively storing samples. However, excessive updates to BN statistics lead to overfitting to specific domain shifts. To address this issue, we propose a resilient practical test-time adaptation method (ResiTTA), employing soft constraints on the BN statistics and a low-entropy sampling strategy, which reduces overfitting on domain shifts and enables rapid adaptation. Specifically, we develop a resilient batch normalization (BN) with estimated statistics and soft constraints between the source and the estimated statistics. The soft constraints regularize the estimated statistics to mitigate overfitting caused by the excessive updates. To avoid overfitting, we design a low-entropy memory bank that accounts for sample uncertainty and class balance. We adapt the source domain model via a teacher-student self-training adaptation on the samples from the memory, incorporating the soft constraints’ updates to BN. Our ResiTTA obtains state-of-the-art results on various benchmarks. We release our code1. Xingzhi Zhou 0002, Zhiliang Tian, Xin Niu 0002, Ka Chun Cheung, Simon See, Nevin Lianwen Zhang |
ICASSP | 6 |
| 2025 | Token-Efficient VLM: High-Resolution Image Understanding Via Dynamic Region Proposal
Yitong Jiang, Jinwei Gu, Tianfan Xue, Ka Chun Cheung, Pavlo Molchanov 0001, Hongxu Yin, Sifei Liu |
ICCV | 4 |
| 2025 | TEVLA: Text-oriented Enhancement for Vision-Language Alignment in Relation ExtractionabstractWith the explosive growth of multimedia data storage, multimodal learning is an inevitable trend for Information Extraction (IE). However, the noise and irrelevance of web- crawled samples cause adverse degradation in each modality. Additionally, previous researches inadequately address the above issue, and the potential of cross-modal fusion remains underexplored. We propose a strengthened alignment module, using a generative text augmentation submodule to reduce noise contamination and emphasize incorporating visual features into texts. We further propose a fusion adapter utilizing a soft-prompt structure for profound fusion. To activate logical capabilities, we apply prompts with a multi-turn dialogue. For the Multimodal Relation Extraction task over the MNRE dataset, our method exceeds the previous SOTA model with a 7% increase in F1-score. It has superior generalization for other multimodal IE tasks, achieving SOTA on Named Entity Recognition over Twitter-15/17 datasets and on Event Extraction over M2E2dataset. Junlin Chen, Qiushan Guo, Ka Chun Cheung, Mingrui Liang, Dezhi Chen |
ICME | 3 |
| 2025 | Align 3D Representation and Text Embedding for 3D Content PersonalizationabstractRecent advances in NeRF and 3DGS have significantly enhanced the efficiency and quality of 3D content synthesis. However, efficient personalization of generated 3D content remains a critical challenge. Current 3D personalization approaches predominantly rely on knowledge distillation-based methods, which require computationally expensive retraining procedures. To address this challenge, we propose Invert3D, a novel framework for convenient 3D content personalization. Nowadays, vision-language models such as CLIP enable direct image personalization through aligned vision-text embedding spaces. However, the inherent structural differences between 3D content and 2D images preclude direct application of these techniques to 3D personalization. Our approach bridges this gap by establishing alignment between 3D representations and text embedding spaces. Specifically, we develop a camera-conditioned 3D-to-text inverse mechanism that projects 3D contents into a 3D embedding aligned with text embeddings. This alignment enables efficient manipulation and personalization of 3D content through natural language prompts, eliminating the need for computationally retraining procedures. Extensive experiments demonstrate that Invert3D achieves effective personalization of 3D content. Qi Song 0003, Ziyuan Luo, Ka Chun Cheung, Simon See, Renjie Wan |
ACM Multimedia | 3 |
| 2025 | Stereo-GS: Multi-View Stereo Vision Model for Generalizable 3D Gaussian Splatting ReconstructionabstractGeneralizable 3D Gaussian Splatting reconstruction showcases advanced Image-to-3D content creation but requires substantial computational resources and large datasets, posing challenges to training models from scratch. Current methods usually entangle the prediction of 3D Gaussian geometry and appearance, which rely heavily on data-driven priors and result in slow regression speeds. To address this, we propose Stereo-GS, a disentangled framework for efficient 3D Gaussian prediction. Our method extracts features from local image pairs using a stereo vision backbone and fuses them via global attention blocks. Dedicated point and Gaussian prediction heads generate multi-view point-maps for geometry and Gaussian features for appearance, combined as GS-maps to represent the 3DGS object. A refinement network enhances these GSmaps for high-quality reconstruction. Unlike existing methods that depend on camera parameters, our approach achieves pose-free 3D reconstruction, improving robustness and practicality. By reducing resource demands while maintaining high-quality outputs, Stereo- GS provides an efficient, scalable solution for real-world 3D content generation. Project page: https://kevinhuangxf.github.io/stereo-gs. Xiufeng Huang, Ka Chun Cheung, Runmin Cong, Simon See, Renjie Wan |
ACM Multimedia | 2 |
| 2025 | ImageSentinel: Protecting Visual Datasets from Unauthorized Retrieval-Augmented Image GenerationabstractThe widespread adoption of Retrieval-Augmented Image Generation (RAIG) has raised significant concerns about the unauthorized use of private image datasets. While these systems have shown remarkable capabilities in enhancing generation quality through reference images, protecting visual datasets from unauthorized use in such systems remains a challenging problem. Traditional digital watermarking approaches face limitations in RAIG systems, as the complex feature extraction and recombination processes fail to preserve watermark signals during generation. To address these challenges, we propose ImageSentinel, a novel framework for protecting visual datasets in RAIG. Our framework synthesizes sentinel images that maintain visual consistency with the original dataset. These sentinels enable protection verification through randomly generated character sequences that serve as retrieval keys. To ensure seamless integration, we leverage vision-language models to generate the sentinel images. Experimental results demonstrate that ImageSentinel effectively detects unauthorized dataset usage while preserving generation quality for authorized applications. Ziyuan Luo, Yangyi Zhao, Ka Chun Cheung, Simon See, Renjie Wan |
NeurIPS | 3 |
| 2025 | GSPN-2: Efficient Parallel Sequence ModelingabstractEfficient 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 cost close to linear in the number of rows or columns, while retaining accuracy. Despite this advancement, the existing GSPN implementation still suffers from (i) heavy overhead due to repeatedly launching GPU kernels, (ii) excessive data transfers from global GPU memory, and (iii) redundant computations caused by maintaining separate propagation weights for each channel. We introduce GSPN-2, a joint algorithm–system redesign. In particular, we eliminate thousands of micro-launches from the previous implementation into one single 2D kernel, explicitly pin one warp to each channel slice, and stage the previous column's activations in shared memory. On the model side, we introduce a set of channel-shared propagation weights that replace per-channel matrices, trimming parameters, and align naturally with the affinity map used in transformer attention. Experiments demonstrate GSPN-2's effectiveness across image classification and text-to-image synthesis tasks, matching transformer-level accuracy with significantly lower computational cost. GSPN-2 establishes a new efficiency frontier for modeling global spatial context in vision applications through its unique combination of structured matrix transformations and GPU-optimized implementation. Yitong Jiang, Collin McCarthy, David Wehr, Hanrong Ye, Ka Chun Cheung, Wonmin Byeon, Jinwei Gu, Kai Han 0001, Hongxu Yin, Pavlo Molchanov 0001, Jan Kautz, Sifei Liu |
NeurIPS | 7 |
| 2024 | TCM-FTP: Fine-Tuning Large Language Models for Herbal Prescription PredictionabstractTraditional Chinese medicine (TCM) has relied on specific combinations of herbs in prescriptions to treat various symptoms and signs for thousands of years. Predicting TCM prescriptions poses a fascinating technical challenge with significant practical implications. However, this task faces limitations due to the scarcity of high-quality clinical datasets and the complex relationship between symptoms and herbs. To address these issues, we introduce DigestDS, a novel dataset comprising practical medical records from experienced experts in digestive system diseases. We also propose a method, TCM-FTP (TCM Fine-Tuning Pre-trained), to leverage pre-trained large language models (LLMs) via supervised fine-tuning on DigestDS. Additionally, we enhance computational efficiency using a low-rank adaptation technique. Moreover, TCM-FTP incorporates data augmentation by permuting herbs within prescriptions, exploiting their order-agnostic nature. Impressively, TCM-FTP achieves an F1-score of 0.8031, significantly outperforming previous methods. Furthermore, it demonstrates remarkable accuracy in dosage prediction, achieving a normalized mean square error of 0.0604. In contrast, LLMs without fine-tuning exhibit poor performance. Although LLMs have demonstrated wide-ranging capabilities, our work underscores the necessity of fine-tuning for TCM prescription prediction and presents an effective way to accomplish this. Xingzhi Zhou 0002, Xin Dong 0017, Chunhao Li, Yuning Bai, Ka Chun Cheung, Simon See, Xinpeng Song, Runshun Zhang, Xuezhong Zhou, Nevin Lianwen Zhang |
BIBM | 6 |
| 2024 | RegionGPT: Towards Region Understanding Vision Language ModelabstractVision 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 data that lacks detailed, region-specific captions. To address this, we introduce RegionGPT (short as RGPT), a novel framework designed for complex region-level captioning and understanding. RGPT enhances the spatial awareness of regional representation with simple yet effective modifications to existing visual encoders in VLMs. We further improve performance on tasks requiring a specific output scope by integrating task-guided instruction prompts during both training and inference phases, while maintaining the model's versatility for general-purpose tasks. Additionally, we develop an automated region caption data generation pipeline, enriching the training set with detailed region-level captions. We demonstrate that a universal RGPT model can be effectively applied and significantly enhancing performance across a range of region-level tasks, including but not limited to complex region descriptions, reasoning, object classification, and referring expressions comprehension. Code will be released at the project page. Qiushan Guo, Shalini De Mello, Hongxu Yin, Wonmin Byeon, Ka Chun Cheung, Yizhou Yu, Ping Luo 0002, Sifei Liu |
CVPR | 5 |
| 2024 | AHIVE: Anatomy-Aware Hierarchical Vision Encoding for Interactive Radiology Report RetrievalabstractAutomatic radiology report generation using deep learning models has been recently explored and found promising. Neural decoders are commonly used for the report generation, where irrelevant and unfaithful contents are unavoidable. The retrieval-based approach alleviates the limitation by identifying reports which are relevant to the input to assist the generation. To achieve clinically accurate report retrieval, we make reference to clinicians' diagnostic steps of examining a radiology image where anatomical and diagnostic details are typically focused, and propose a novel hierarchical visual concept representation called anatomy-aware hierarchical vision encoding (AHIVE). To learn AHIVE, we first derive a methodology to extract hierarchical diagnostic descriptions from radiology reports and develop a CLIP-based framework for the model training. Also, the hierarchical architecture of AHIVE is designed to support interactive report retrieval so that report revision made at one layer can be propagated to the subsequent ones to trigger other necessary revisions. We conduct extensive experiments and show that AHIVE can outperform the SOTA vision-language retrieval methods in terms of clinical accuracy by a large margin. We provide also a case study to illustrate how it enables interactive report retrieval. Sixing Yan, William Kwok-Wai Cheung, Ivor W. Tsang, Wan Hang Keith Chiu, Terence M. Tong, Ka Chun Cheung, Simon See |
CVPR | 6 |
| 2024 | GeometrySticker: Enabling Ownership Claim of Recolorized Neural Radiance Fields
Xiufeng Huang, Ka Chun Cheung, Simon See, Renjie Wan |
ECCV (9) | 2 |
| 2024 | Protecting NeRFs' Copyright via Plug-And-Play Watermarking Base Model
Qi Song 0003, Ziyuan Luo, Ka Chun Cheung, Simon See, Renjie Wan |
ECCV (11) | 3 |
| 2024 | Geometry Cloak: Preventing TGS-based 3D Reconstruction from Copyrighted ImagesabstractSingle-view 3D reconstruction methods like Triplane Gaussian Splatting (TGS) have enabled high-quality 3D model generation from just a single image input within seconds. However, this capability raises concerns about potential misuse, where malicious users could exploit TGS to create unauthorized 3D models from copyrighted images. To prevent such infringement, we propose a novel image protection approach that embeds invisible geometry perturbations, termed ``geometry cloaks'', into images before supplying them to TGS. These carefully crafted perturbations encode a customized message that is revealed when TGS attempts 3D reconstructions of the cloaked image. Unlike conventional adversarial attacks that simply degrade output quality, our method forces TGS to fail the 3D reconstruction in a specific way - by generating an identifiable customized pattern that acts as a watermark. This watermark allows copyright holders to assert ownership over any attempted 3D reconstructions made from their protected images. Extensive experiments have verified the effectiveness of our geometry cloak. Qi Song 0003, Ziyuan Luo, Ka Chun Cheung, Simon See, Renjie Wan |
NeurIPS | 3 |
| 2024 | GaussianMarker: Uncertainty-Aware Copyright Protection of 3D Gaussian Splattingabstract3D Gaussian Splatting (3DGS) has become a crucial method for acquiring 3D assets. To protect the copyright of these assets, digital watermarking techniques can be applied to embed ownership information discreetly within 3DGS mod- els. However, existing watermarking methods for meshes, point clouds, and implicit radiance fields cannot be directly applied to 3DGS models, as 3DGS models use explicit 3D Gaussians with distinct structures and do not rely on neural networks. Naively embedding the watermark on a pre-trained 3DGS can cause obvious distortion in rendered images. In our work, we propose an uncertainty- based method that constrains the perturbation of model parameters to achieve invisible watermarking for 3DGS. At the message decoding stage, the copyright messages can be reliably extracted from both 3D Gaussians and 2D rendered im- ages even under various forms of 3D and 2D distortions. We conduct extensive experiments on the Blender, LLFF, and MipNeRF-360 datasets to validate the effectiveness of our proposed method, demonstrating state-of-the-art performance on both message decoding accuracy and view synthesis quality. Xiufeng Huang, Yiu-Ming Cheung, Ka Chun Cheung, Simon See, Renjie Wan |
NeurIPS | 4 |
| 2023 | NAS-LID: Efficient Neural Architecture Search with Local Intrinsic DimensionabstractOne-shot neural architecture search (NAS) substantially improves the search efficiency by training one supernet to estimate the performance of every possible child architecture (i.e., subnet). However, the inconsistency of characteristics among subnets incurs serious interference in the optimization, resulting in poor performance ranking correlation of subnets. Subsequent explorations decompose supernet weights via a particular criterion, e.g., gradient matching, to reduce the interference; yet they suffer from huge computational cost and low space separability. In this work, we propose a lightweight and effective local intrinsic dimension (LID)-based method NAS-LID. NAS-LID evaluates the geometrical properties of architectures by calculating the low-cost LID features layer-by-layer, and the similarity characterized by LID enjoys better separability compared with gradients, which thus effectively reduces the interference among subnets. Extensive experiments on NASBench-201 indicate that NAS-LID achieves superior performance with better efficiency. Specifically, compared to the gradient-driven method, NAS-LID can save up to 86% of GPU memory overhead when searching on NASBench-201. We also demonstrate the effectiveness of NAS-LID on ProxylessNAS and OFA spaces. Source code:https://github.com/marsggbo/NAS-LID. Xin He 0019, Jiangchao Yao, Yuxin Wang 0003, Zhenheng Tang, Ka Chun Cheung, Simon See, Bo Han 0003, Xiaowen Chu 0001 |
AAAI | 5 |
| 2023 | A Simple Baseline for Video Restoration with Grouped Spatial-Temporal ShiftabstractVideo restoration, which aims to restore clear frames from degraded videos, has numerous important applications. The key to video restoration depends on utilizing inter-frame information. However, existing deep learning methods often rely on complicated network architectures, such as optical flow estimation, deformable convo-lution, and cross-frame self-attention layers, resulting in high computational costs. In this study, we propose a sim-ple yet effective framework for video restoration. Our approach is based on grouped spatial-temporal shift, which is a lightweight and straightforward technique that can implicitly capture inter-frame correspondences for multi-frame aggregation. By introducing grouped spatial shift, we attain expansive effective receptive fields. Combined with basic 2D convolution, this simple framework can effectively aggregate inter-frame information. Extensive experiments demonstrate that our framework outperforms the previous state-of-the-art method, while using less than a quarter of its computational cost, on both video deblurring and video denoising tasks. These results indicate the potential for our approach to significantly reduce computational overhead while maintaining high-quality results. Code is avaliable at https://github.com/dasonglil/Shift-Net. Dasong Li, Xiaoyu Shi 0002, Yi Zhang 0108, Ka Chun Cheung, Simon See, Xiaogang Wang 0001, Hongwei Qin, Hongsheng Li 0001 |
CVPR | 4 |
| 2023 | FlowFormer++: Masked Cost Volume Autoencoding for Pretraining Optical Flow EstimationabstractFlowFormer [24] introduces a transformer architecture into optical flow estimation and achieves state-of-the-art performance. The core component of FlowFormer is the transformer-based cost-volume encoder. Inspired by the recent success of masked autoencoding (MAE) pretraining in unleashing transformers' capacity of encoding visual representation, we propose Masked Cost Volume Autoencoding (MCVA) to enhance FlowFormer by pretraining the cost-volume encoder with a novel MAE scheme. Firstly, we introduce a block-sharing masking strategy to prevent masked information leakage, as the cost maps of neighboring source pixels are highly correlated. Secondly, we propose a novel pre-text reconstruction task, which encourages the cost-volume encoder to aggregate long-range information and ensures pretraining-finetuning consistency. We also show how to modify the FlowFormer architecture to accommodate masks during pretraining. Pretrained with MCVA, FlowFormer++ ranks 1st among published methods on both Sintel and KITTI-2015 benchmarks. Specifically, FlowFormer++ achieves 1.07 and 1.94 average end-point error (AEPE) on the clean and final pass of Sintel benchmark, leading to 7.76% and 7.18% error reductions from FlowFormer. FlowFormer++ obtains 4.52 F1-all on the KITTI-2015 test set, improving FlowFormer by 0.16. Xiaoyu Shi 0002, Dasong Li, Manyuan Zhang, Ka Chun Cheung, Simon See, Hongwei Qin, Jifeng Dai, Hongsheng Li 0001 |
CVPR | 5 |
| 2023 | TrajectoryFormer: 3D Object Tracking Transformer with Predictive Trajectory Hypothesesabstract3D multi-object tracking (MOT) is vital for many applications including autonomous driving vehicles and service robots. With the commonly used tracking-by-detection paradigm, 3D MOT has made important progress in recent years. However, these methods only use the detection boxes of the current frame to obtain trajectory-box association results, which makes it impossible for the tracker to recover objects missed by the detector. In this paper, we present TrajectoryFormer, a novel point-cloud-based 3D MOT framework. To recover the missed object by detector, we generates multiple trajectory hypotheses with hybrid candidate boxes, including temporally predicted boxes and current-frame detection boxes, for trajectory-box association. The predicted boxes can propagate object’s history trajectory information to the current frame and thus the network can tolerate short-term miss detection of the tracked objects. We combine long-term object motion feature and short-term object appearance feature to create per-hypothesis feature embedding, which reduces the computational overhead for spatial-temporal encoding. Additionally, we introduce a Global-Local Interaction Module to conduct information interaction among all hypotheses and models their spatial relations, leading to accurate estimation of hypotheses. Our TrajectoryFormer achieves state-of-the-art performance on the Waymo 3D MOT benchmarks. Code is available at https://github.com/poodarchu/EFG. Xuesong Chen 0001, Shaoshuai Shi, Benjin Zhu, Qiang Wang 0023, Ka Chun Cheung, Simon See, Hongsheng Li 0001 |
ICCV | 6 |
| 2023 | CopyRNeRF: Protecting the CopyRight of Neural Radiance FieldsabstractNeural Radiance Fields (NeRF) have the potential to be a major representation of media. Since training a NeRF has never been an easy task, the protection of its model copyright should be a priority. In this paper, by analyzing the pros and cons of possible copyright protection solutions, we propose to protect the copyright of NeRF models by replacing the original color representation in NeRF with a watermarked color representation. Then, a distortion-resistant rendering scheme is designed to guarantee robust message extraction in 2D renderings of NeRF. Our proposed method can directly protect the copyright of NeRF models while maintaining high rendering quality and bit accuracy when compared among optional solutions. Project page: https://luo-ziyuan.github.io/copyrnerf. Ziyuan Luo, Qing Guo 0005, Ka Chun Cheung, Simon See, Renjie Wan |
ICCV | 3 |
| 2023 | VideoFlow: Exploiting Temporal Cues for Multi-frame Optical Flow EstimationabstractWe introduce VideoFlow, a novel optical flow estimation framework for videos. In contrast to previous methods that learn to estimate optical flow from two frames, VideoFlow concurrently estimates bi-directional optical flows for multiple frames that are available in videos by sufficiently exploiting temporal cues.We first propose a TRi-frame Optical Flow (TROF) module that estimates bi-directional optical flows for the center frame in a three-frame manner. The information of the frame triplet is iteratively fused onto the center frame. To extend TROF for handling more frames, we further propose a MOtion Propagation (MOP) module that bridges multiple TROFs and propagates motion features between adjacent TROFs. With the iterative flow estimation refinement, the information fused in individual TROFs can be propagated into the whole sequence via MOP. By effectively exploiting video information, VideoFlow presents extraordinary performance, ranking 1st on all public benchmarks. On the Sintel benchmark, VideoFlow achieves 1.649 and 0.991 average end-point-error (AEPE) on the final and clean passes, a 15.1% and 7.6% error reduction from the best published results (1.943 and 1.073 from FlowFormer++). On the KITTI-2015 benchmark, VideoFlow achieves an F1-all error of 3.65%, a 19.2% error reduction from the best published result (4.52% from FlowFormer++). Code is released at https://github.com/XiaoyuShi97/VideoFlow. Xiaoyu Shi 0002, Weikang Bian, Dasong Li, Manyuan Zhang, Ka Chun Cheung, Simon See, Hongwei Qin, Jifeng Dai, Hongsheng Li 0001 |
ICCV | 6 |
| 2023 | IRCasTRF: Inverse Rendering by Optimizing Cascaded Tensorial Radiance Fields, Lighting, and Materials From Multi-view ImagesabstractWe propose an inverse rendering pipeline that simultaneously reconstructs scene geometry, lighting, and spatially-varying material from a set of multi-view images. Specifically, the proposed pipeline involves volume and physics-based rendering, which are performed separately in two steps: exploration and exploitation. During the exploration step, our method utilizes the compactness of neural radiance fields and a flexible differentiable volume rendering technique to learn an initial volumetric field. Here, we introduce a novel cascaded tensorial radiance field method on top of the Canonical Polyadic (CP) decomposition to boost model compactness beyond conventional methods. In the exploitation step, a shading pass that incorporates a differentiable physics-based shading method is applied to jointly optimize the scene's geometry, spatially-varying materials, and lighting, using image reconstruction loss. Experimental results demonstrate that our proposed inverse rendering pipeline, IRCasTRF, outperforms prior works in inverse rendering quality. The final output is highly compatible with downstream applications like scene editing and advanced simulations. Further details are available on the project page: https://ircasrf.github.io/. Wenpeng Xing, Jie Chen 0026, Ka Chun Cheung, Simon See |
ACM Multimedia | 3 |
| 2023 | Transfer Learning With Singular Value Decomposition of Multichannel Convolution MatricesabstractThe task of transfer learning using pretrained convolutional neural networks is considered. We propose a convolution-SVD layer to analyze the convolution operators with a singular value decomposition computed in the Fourier domain. Singular vectors extracted from the source domain are transferred to the target domain, whereas the singular values are fine-tuned with a target data set. In this way, dimension reduction is achieved to avoid overfitting, while some flexibility to fine-tune the convolution kernels is maintained. We extend an existing convolution kernel reconstruction algorithm to allow for a reconstruction from an arbitrary set of learned singular values. A generalization bound for a single convolution-SVD layer is devised to show the consistency between training and testing errors. We further introduce a notion of transfer learning gap. We prove that the testing error for a single convolution-SVD layer is bounded in terms of the gap, which motivates us to develop a regularization model with the gap as the regularizer. Numerical experiments are conducted to demonstrate the superiority of the proposed model in solving classification problems and the influence of various parameters. In particular, the regularization is shown to yield a significantly higher prediction accuracy. Tak Shing Au Yeung, Ka Chun Cheung, Michael Kwok-Po Ng, Simon See, Andy M. Yip |
Neural Comput. | 2 |
| 2023 | Attributed Abnormality Graph Embedding for Clinically Accurate X-Ray Report GenerationabstractDespite the recent success of deep learning models for text generation, generating clinically accurate reports remains challenging. More precisely modeling the relationships of the abnormalities revealed in an X-ray image has been found promising to enhance the clinical accuracy. In this paper, we first introduce a novel knowledge graph structure called an attributed abnormality graph (ATAG). It consists of interconnected abnormality nodes and attribute nodes for better capturing more fine-grained abnormality details. In contrast to the existing methods where the abnormality graph are constructed manually, we propose a methodology to automatically construct the fine-grained graph structure based on annotated X-ray reports and the RadLex radiology lexicon. We then learn the ATAG embeddings as part of a deep model with an encoder-decoder architecture for the report generation. In particular, graph attention networks are explored to encode the relationships among the abnormalities and their attributes. A hierarchical attention attention and a gating mechanism are specifically designed to further enhance the generation quality. We carry out extensive experiments based on the benchmark datasets, and show that the proposed ATAG-based deep model outperforms the SOTA methods by a large margin in ensuring the clinical accuracy of the generated reports. Sixing Yan, William Kwok-Wai Cheung, Wan Hang Keith Chiu, Terence M. Tong, Ka Chun Cheung, Simon See |
IEEE Trans. Medical Imaging | 5 |
| 2022 | MPPNet: Multi-frame Feature Intertwining with Proxy Points for 3D Temporal Object Detection
Xuesong Chen 0001, Shaoshuai Shi, Benjin Zhu, Ka Chun Cheung, Hang Xu 0004, Hongsheng Li 0001 |
ECCV (8) | 4 |
| 2022 | FlowFormer: A Transformer Architecture for Optical Flow
Xiaoyu Shi 0002, Qiang Wang 0023, Ka Chun Cheung, Hongwei Qin, Jifeng Dai, Hongsheng Li 0001 |
ECCV (17) | 5 |
| 2022 | Learning Degradation Representations for Image Deblurring
Dasong Li, Yi Zhang 0108, Ka Chun Cheung, Xiaogang Wang 0001, Hongwei Qin, Hongsheng Li 0001 |
ECCV (18) | 3 |
| 2022 | Adaptive Label Smoothing with Self-Knowledge in Natural Language GenerationabstractOverconfidence has been shown to impair generalization and calibration of a neural network.Previous studies remedy this issue by adding a regularization term to a loss function, preventing a model from making a peaked distribution.Label smoothing smoothes target labels with a pre-defined prior label distribution; as a result, a model is learned to maximize the likelihood of predicting the soft label.Nonetheless, the amount of smoothing is the same in all samples and remains fixed in training.In other words, label smoothing does not reflect the change in probability distribution mapped by a model over the course of training.To address this issue, we propose a regularization scheme that brings dynamic nature into the smoothing parameter by taking model probability distribution into account, thereby varying the parameter per instance.A model in training self-regulates the extent of smoothing on the fly during forward propagation.Furthermore, inspired by recent work in bridging label smoothing and knowledge distillation, our work utilizes self-knowledge as a prior label distribution in softening target labels, and presents theoretical support for the regularization effect by knowledge distillation and the dynamic smoothing parameter.Our regularizer is validated comprehensively, and the result illustrates marked improvements in model generalization and calibration, enhancing robustness and trustworthiness of a model. Ka Chun Cheung, Nevin Lianwen Zhang |
EMNLP | 2 |
| 2022 | Hard Gate Knowledge Distillation - Leverage Calibration for Robust and Reliable Language ModelabstractIn knowledge distillation, a student model is trained with supervisions from both knowledge from a teacher and observations drawn from a training data distribution.Knowledge of a teacher is considered a subject that holds interclass relations which send a meaningful supervision to a student; hence, much effort has been put to find such knowledge to be distilled.In this paper, we explore a question that has been given little attention: "when to distill such knowledge."The question is answered in our work with the concept of model calibration; we view a teacher model not only as a source of knowledge but also as a gauge to detect miscalibration of a student.This simple and yet novel view leads to a hard gate knowledge distillation scheme that switches between learning from a teacher model and training data.We verify the gating mechanism in the context of natural language generation at both the token-level and the sentence-level.Empirical comparisons with strong baselines show that hard gate knowledge distillation not only improves model generalization, but also significantly lowers model calibration error. Zhiliang Tian, Yingxiu Zhao, Ka Chun Cheung, Nevin Lianwen Zhang |
EMNLP | 4 |
| 2022 | NeuralMarker: A Framework for Learning General Marker CorrespondenceabstractWe tackle the problem of estimating correspondences from a general marker, such as a movie poster, to an image that captures such a marker. Conventionally, this problem is addressed by fitting a homography model based on sparse feature matching. However, they are only able to handle plane-like markers and the sparse features do not sufficiently utilize appearance information. In this paper, we propose a novel framework NeuralMarker, training a neural network estimating dense marker correspondences under various challenging conditions, such as marker deformation, harsh lighting, etc. Deep learning has presented an excellent performance in correspondence learning once provided with sufficient training data. However, annotating pixel-wise dense correspondence for training marker correspondence is too expensive. We observe that the challenges of marker correspondence estimation come from two individual aspects: geometry variation and appearance variation. We, therefore, design two components addressing these two challenges in NeuralMarker. First, we create a synthetic dataset FlyingMarkers containing marker-image pairs with ground truth dense correspondences. By training with FlyingMarkers, the neural network is encouraged to capture various marker motions. Second, we propose the novel Symmetric Epipolar Distance (SED) loss, which enables learning dense correspondence from posed images. Learning with the SED loss and the cross-lighting posed images collected by Structure-from-Motion (SfM), NeuralMarker is remarkably robust in harsh lighting environments and avoids synthetic image bias. Besides, we also propose a novel marker correspondence evaluation method circumstancing annotations on real marker-image pairs and create a new benchmark. We show that NeuralMarker significantly outperforms previous methods and enables new interesting applications, including Augmented Reality (AR) and video editing. Xiaokun Pan, Weihong Pan, Weikang Bian, Ka Chun Cheung, Guofeng Zhang 0001, Hongsheng Li 0001 |
ACM Trans. Graph. | 6 |
| 2021 | Recent advance in machine learning for partial differential equation
Ka Chun Cheung, Simon See |
CCF Trans. High Perform. Comput. | 1 |
| 2020 | Self-Attention-Based Fully-Inception Networks for Continuous Sign Language RecognitionabstractIn hearing-loss community, sign language is a primary tool to communicate with people while there is communication gap between hearing-loss people with normal hearing people. Continuous sign language recognition, which can bridge the communication gap, is a challenging task because of the weakly supervised ordered annotations where no frame-level label is provided. To overcome this problem, connectionist temporal classification (CTC) is the most widely used method. However, CTC learning could perform bad if extracted features are not good. For better feature extraction, this work presents the novel self-attention-based fully-inception (SAFI) networks for vision-based end-to-end continuous sign language recognition. Considering the length of sign words differs from each other, we introduce fully inception network with different receptive field to extract dynamic clip-level features. To further boost the performance, the fully inception network with an auxiliary classifier is trained with aggregation cross entropy (ACE) loss. Then the self-attention networks as global sequential feature extractor is used to model the clip-level features with CTC. The proposed model is optimized by jointly training with ACE on clip-level feature learning and CTC on global sequential feature learning in an end-to-end fashion. The best method in the baselines achieves 35.6% WER on validation set and 34.5% WER on test set. It employs a better decoding algorithm for pseudo label to do the EM-like optimization to fine tune CNN module. In contrast, our approach focuses on the better feature extraction for end-to-end learning. To alleviate the overfitting on the limited dataset, we employ temporal elastic deformation to triple the real-world dataset RWTH-PHOENIX-Weather 2014. Experimental results on the real-world dataset RWTH-PHOENIX-Weather 2014 demonstrate the effectiveness of our approach which achieves 31.7% WER on validation set and 31.3% WER on test set. Mingjie Zhou, Michael Kwok-Po Ng, Zixin Cai, Ka Chun Cheung |
ECAI | 4 |