Search Results for author: Alex C. Kot

Found 57 papers, 17 papers with code

Collaborative Learning of Gesture Recognition and 3D Hand Pose Estimation with Multi-Order Feature Analysis

no code implementations ECCV 2020 Siyuan Yang, Jun Liu, Shijian Lu, Meng Hwa Er, Alex C. Kot

The proposed network exploits joint-aware features that are crucial for both tasks, with which gesture recognition and 3D hand pose estimation boost each other to learn highly discriminative features and models.

3D Hand Pose Estimation Gesture Recognition

I2CANSAY:Inter-Class Analogical Augmentation and Intra-Class Significance Analysis for Non-Exemplar Online Task-Free Continual Learning

no code implementations21 Apr 2024 Songlin Dong, Yingjie Chen, Yuhang He, Yuhan Jin, Alex C. Kot, Yihong Gong

Online task-free continual learning (OTFCL) is a more challenging variant of continual learning which emphasizes the gradual shift of task boundaries and learns in an online mode.

MoE-FFD: Mixture of Experts for Generalized and Parameter-Efficient Face Forgery Detection

no code implementations12 Apr 2024 Chenqi Kong, Anwei Luo, Song Xia, Yi Yu, Haoliang Li, Alex C. Kot

Moreover, MoE-FFD leverages the expressivity of transformers and local priors of CNNs to simultaneously extract global and local forgery clues.

Cross-Domain Few-Shot Segmentation via Iterative Support-Query Correspondence Mining

1 code implementation16 Jan 2024 Jiahao Nie, Yun Xing, Gongjie Zhang, Pei Yan, Aoran Xiao, Yap-Peng Tan, Alex C. Kot, Shijian Lu

Cross-Domain Few-Shot Segmentation (CD-FSS) poses the challenge of segmenting novel categories from a distinct domain using only limited exemplars.

Cross-Domain Few-Shot

SinSR: Diffusion-Based Image Super-Resolution in a Single Step

1 code implementation23 Nov 2023 YuFei Wang, Wenhan Yang, Xinyuan Chen, Yaohui Wang, Lanqing Guo, Lap-Pui Chau, Ziwei Liu, Yu Qiao, Alex C. Kot, Bihan Wen

Extensive experiments conducted on synthetic and real-world datasets demonstrate that the proposed method can achieve comparable or even superior performance compared to both previous SOTA methods and the teacher model, in just one sampling step, resulting in a remarkable up to x10 speedup for inference.

Image Super-Resolution

Forgery-aware Adaptive Vision Transformer for Face Forgery Detection

no code implementations20 Sep 2023 Anwei Luo, Rizhao Cai, Chenqi Kong, Xiangui Kang, Jiwu Huang, Alex C. Kot

To circumvent these issues, we propose a novel Forgery-aware Adaptive Vision Transformer (FA-ViT).

Face Swapping

ExposureDiffusion: Learning to Expose for Low-light Image Enhancement

1 code implementation ICCV 2023 YuFei Wang, Yi Yu, Wenhan Yang, Lanqing Guo, Lap-Pui Chau, Alex C. Kot, Bihan Wen

Different from a vanilla diffusion model that has to perform Gaussian denoising, with the injected physics-based exposure model, our restoration process can directly start from a noisy image instead of pure noise.

Image Denoising Low-Light Image Enhancement

One-Shot Action Recognition via Multi-Scale Spatial-Temporal Skeleton Matching

no code implementations14 Jul 2023 Siyuan Yang, Jun Liu, Shijian Lu, Er Meng Hwa, Alex C. Kot

The first is multi-scale matching which captures the scale-wise semantic relevance of skeleton data at multiple spatial and temporal scales simultaneously.

Action Recognition

Enhancing Low-Light Images Using Infrared-Encoded Images

no code implementations9 Jul 2023 Shulin Tian, YuFei Wang, Renjie Wan, Wenhan Yang, Alex C. Kot, Bihan Wen

In this work, we propose a novel approach to increase the visibility of images captured under low-light environments by removing the in-camera infrared (IR) cut-off filter, which allows for the capture of more photons and results in improved signal-to-noise ratio due to the inclusion of information from the IR spectrum.

Low-Light Image Enhancement

Beyond Learned Metadata-based Raw Image Reconstruction

1 code implementation21 Jun 2023 YuFei Wang, Yi Yu, Wenhan Yang, Lanqing Guo, Lap-Pui Chau, Alex C. Kot, Bihan Wen

Besides, we propose a novel design of the context model, which can better predict the order masks of encoding/decoding based on both the sRGB image and the masks of already processed features.

Image Compression Image Reconstruction +1

Self-Supervised 3D Action Representation Learning with Skeleton Cloud Colorization

no code implementations18 Apr 2023 Siyuan Yang, Jun Liu, Shijian Lu, Er Meng Hwa, Yongjian Hu, Alex C. Kot

We investigate self-supervised representation learning and design a novel skeleton cloud colorization technique that is capable of learning spatial and temporal skeleton representations from unlabeled skeleton sequence data.

Colorization Representation Learning +2

Confidence Attention and Generalization Enhanced Distillation for Continuous Video Domain Adaptation

no code implementations18 Mar 2023 Xiyu Wang, Yuecong Xu, Jianfei Yang, Bihan Wen, Alex C. Kot

The second module compares the outputs of augmented data from the current model to the outputs of weakly augmented data from the source model, forming a novel consistency regularization on the model to alleviate the accumulation of prediction errors.

Autonomous Driving Self-Knowledge Distillation +1

Unsupervised Deep Digital Staining For Microscopic Cell Images Via Knowledge Distillation

no code implementations3 Mar 2023 Ziwang Xu, Lanqing Guo, Shuyan Zhang, Alex C. Kot, Bihan Wen

In this work, we propose a novel unsupervised deep learning framework for the digital staining of cell images using knowledge distillation and generative adversarial networks (GANs).

Colorization Knowledge Distillation +1

Temporal Coherent Test-Time Optimization for Robust Video Classification

no code implementations28 Feb 2023 Chenyu Yi, Siyuan Yang, YuFei Wang, Haoliang Li, Yap-Peng Tan, Alex C. Kot

To exploit information in video with self-supervised learning, TeCo uses global content from video clips and optimizes models for entropy minimization.

Classification Self-Supervised Learning +1

Backdoor Attacks Against Deep Image Compression via Adaptive Frequency Trigger

no code implementations CVPR 2023 Yi Yu, YuFei Wang, Wenhan Yang, Shijian Lu, Yap-Peng Tan, Alex C. Kot

Extensive experiments show that with our trained trigger injection models and simple modification of encoder parameters (of the compression model), the proposed attack can successfully inject several backdoors with corresponding triggers in a single image compression model.

Backdoor Attack Face Recognition +2

Generalized Few-Shot Continual Learning with Contrastive Mixture of Adapters

1 code implementation12 Feb 2023 Yawen Cui, Zitong Yu, Rizhao Cai, Xun Wang, Alex C. Kot, Li Liu

The goal of Few-Shot Continual Learning (FSCL) is to incrementally learn novel tasks with limited labeled samples and preserve previous capabilities simultaneously, while current FSCL methods are all for the class-incremental purpose.

Continual Learning Contrastive Learning +2

Removing Image Artifacts From Scratched Lens Protectors

1 code implementation11 Feb 2023 YuFei Wang, Renjie Wan, Wenhan Yang, Bihan Wen, Lap-Pui Chau, Alex C. Kot

Removing image artifacts from the scratched lens protector is inherently challenging due to the occasional flare artifacts and the co-occurring interference within mixed artifacts.

JPEG Artifact Removal

Virtual Try-On with Pose-Garment Keypoints Guided Inpainting

1 code implementation ICCV 2023 Zhi Li, Pengfei Wei, Xiang Yin, Zejun Ma, Alex C. Kot

In our method, human pose and garment keypoints are extracted from source images and constructed as graphs to predict the garment keypoints at the target pose.

Virtual Try-on

Forensicability Assessment of Questioned Images in Recapturing Detection

no code implementations5 Sep 2022 Changsheng chen, Lin Zhao, Rizhao Cai, Zitong Yu, Jiwu Huang, Alex C. Kot

We integrate the trained FANet with practical recapturing detection schemes in face anti-spoofing and recaptured document detection tasks.

Face Anti-Spoofing Image Quality Assessment

Benchmarking Joint Face Spoofing and Forgery Detection with Visual and Physiological Cues

no code implementations10 Aug 2022 Zitong Yu, Rizhao Cai, Zhi Li, Wenhan Yang, Jingang Shi, Alex C. Kot

In this paper, we establish the first joint face spoofing and forgery detection benchmark using both visual appearance and physiological rPPG cues.

Benchmarking DeepFake Detection +3

One-Class Knowledge Distillation for Face Presentation Attack Detection

1 code implementation8 May 2022 Zhi Li, Rizhao Cai, Haoliang Li, Kwok-Yan Lam, Yongjian Hu, Alex C. Kot

Under this framework, a teacher network is trained with source domain samples to provide discriminative feature representations for face PAD.

Face Presentation Attack Detection

Towards Robust Rain Removal Against Adversarial Attacks: A Comprehensive Benchmark Analysis and Beyond

1 code implementation CVPR 2022 Yi Yu, Wenhan Yang, Yap-Peng Tan, Alex C. Kot

Finally, we examine various types of adversarial attacks that are specific to deraining problems and their effects on both human and machine vision tasks, including 1) rain region attacks, adding perturbations only in the rain regions to make the perturbations in the attacked rain images less visible; 2) object-sensitive attacks, adding perturbations only in regions near the given objects.

Rain Removal

DEX: Domain Embedding Expansion for Generalized Person Re-identification

no code implementations21 Oct 2021 Eugene P. W. Ang, Lin Shan, Alex C. Kot

With DEX and DEXLite, existing methods can gain significant improvements when tested on other unseen datasets, thereby demonstrating the general applicability of our method.

Domain Generalization Person Re-Identification

Asymmetric Modality Translation For Face Presentation Attack Detection

no code implementations18 Oct 2021 Zhi Li, Haoliang Li, Xin Luo, Yongjian Hu, Kwok-Yan Lam, Alex C. Kot

In this paper, we propose a novel framework based on asymmetric modality translation for face presentation attack detection in bi-modality scenarios.

Face Presentation Attack Detection Face Recognition +1

Disentangled Feature Representation for Few-shot Image Classification

1 code implementation26 Sep 2021 Hao Cheng, YuFei Wang, Haoliang Li, Alex C. Kot, Bihan Wen

In this work, we propose a novel Disentangled Feature Representation framework, dubbed DFR, for few-shot learning applications.

Benchmarking Classification +3

Low-Light Image Enhancement with Normalizing Flow

1 code implementation13 Sep 2021 YuFei Wang, Renjie Wan, Wenhan Yang, Haoliang Li, Lap-Pui Chau, Alex C. Kot

To enhance low-light images to normally-exposed ones is highly ill-posed, namely that the mapping relationship between them is one-to-many.

Low-Light Image Enhancement

Variational Disentanglement for Domain Generalization

1 code implementation13 Sep 2021 YuFei Wang, Haoliang Li, Hao Cheng, Bihan Wen, Lap-Pui Chau, Alex C. Kot

Domain generalization aims to learn an invariant model that can generalize well to the unseen target domain.

Disentanglement Domain Generalization +1

Skeleton Cloud Colorization for Unsupervised 3D Action Representation Learning

no code implementations ICCV 2021 Siyuan Yang, Jun Liu, Shijian Lu, Meng Hwa Er, Alex C. Kot

We investigate unsupervised representation learning for skeleton action recognition, and design a novel skeleton cloud colorization technique that is capable of learning skeleton representations from unlabeled skeleton sequence data.

3D Action Recognition Colorization +1

Embracing the Dark Knowledge: Domain Generalization Using Regularized Knowledge Distillation

no code implementations6 Jul 2021 YuFei Wang, Haoliang Li, Lap-Pui Chau, Alex C. Kot

Though convolutional neural networks are widely used in different tasks, lack of generalization capability in the absence of sufficient and representative data is one of the challenges that hinder their practical application.

Domain Generalization Image Classification +1

Panoramic Image Reflection Removal

no code implementations CVPR 2021 Yuchen Hong, Qian Zheng, Lingran Zhao, Xudong Jiang, Alex C. Kot, Boxin Shi

This paper studies the problem of panoramic image reflection removal, aiming at reliving the content ambiguity between reflection and transmission scenes.

Reflection Removal

Multi-Domain Adversarial Feature Generalization for Person Re-Identification

no code implementations25 Nov 2020 Shan Lin, Chang-Tsun Li, Alex C. Kot

To make Person Re-ID systems more practical and scalable, several cross-dataset domain adaptation methods have been proposed, which achieve high performance without the labeled data from the target domain.

Domain Generalization Person Re-Identification +1

Skeleton-based Relational Reasoning for Group Activity Analysis

no code implementations11 Nov 2020 Mauricio Perez, Jun Liu, Alex C. Kot

In this paper, we leverage the skeleton information to learn the interactions between the individuals straight from it.

Group Activity Recognition Optical Flow Estimation +1

Light Can Hack Your Face! Black-box Backdoor Attack on Face Recognition Systems

no code implementations15 Sep 2020 Haoliang Li, Yufei Wang, Xiaofei Xie, Yang Liu, Shiqi Wang, Renjie Wan, Lap-Pui Chau, Alex C. Kot

In this paper, we propose a novel black-box backdoor attack technique on face recognition systems, which can be conducted without the knowledge of the targeted DNN model.

Backdoor Attack Face Recognition

Heterogeneous Domain Generalization via Domain Mixup

no code implementations11 Sep 2020 Yufei Wang, Haoliang Li, Alex C. Kot

One of the main drawbacks of deep Convolutional Neural Networks (DCNN) is that they lack generalization capability.

Domain Generalization

Interaction Relational Network for Mutual Action Recognition

1 code implementation11 Oct 2019 Mauricio Perez, Jun Liu, Alex C. Kot

Our solution is able to achieve state-of-the-art performance on the traditional interaction recognition datasets SBU and UT, and also on the mutual actions from the large-scale dataset NTU RGB+D.

Action Recognition Human Interaction Recognition +1

NTU RGB+D 120: A Large-Scale Benchmark for 3D Human Activity Understanding

3 code implementations12 May 2019 Jun Liu, Amir Shahroudy, Mauricio Perez, Gang Wang, Ling-Yu Duan, Alex C. Kot

Research on depth-based human activity analysis achieved outstanding performance and demonstrated the effectiveness of 3D representation for action recognition.

Action Recognition One-Shot 3D Action Recognition +1

SPLINE-Net: Sparse Photometric Stereo through Lighting Interpolation and Normal Estimation Networks

no code implementations ICCV 2019 Qian Zheng, Yiming Jia, Boxin Shi, Xudong Jiang, Ling-Yu Duan, Alex C. Kot

This paper solves the Sparse Photometric stereo through Lighting Interpolation and Normal Estimation using a generative Network (SPLINE-Net).

Face Image Reflection Removal

no code implementations3 Mar 2019 Renjie Wan, Boxin Shi, Haoliang Li, Ling-Yu Duan, Alex C. Kot

Face images captured through the glass are usually contaminated by reflections.

Face Recognition Reflection Removal

Skeleton-Based Online Action Prediction Using Scale Selection Network

no code implementations8 Feb 2019 Jun Liu, Amir Shahroudy, Gang Wang, Ling-Yu Duan, Alex C. Kot

Since there are significant temporal scale variations in the observed part of the ongoing action at different time steps, a novel window scale selection method is proposed to make our network focus on the performed part of the ongoing action and try to suppress the possible incoming interference from the previous actions at each step.

Skeleton Based Action Recognition

Feature Boosting Network For 3D Pose Estimation

no code implementations15 Jan 2019 Jun Liu, Henghui Ding, Amir Shahroudy, Ling-Yu Duan, Xudong Jiang, Gang Wang, Alex C. Kot

Learning a set of features that are reliable and discriminatively representative of the pose of a hand (or body) part is difficult due to the ambiguities, texture and illumination variation, and self-occlusion in the real application of 3D pose estimation.

3D Hand Pose Estimation 3D Pose Estimation

Intermediate Deep Feature Compression: the Next Battlefield of Intelligent Sensing

no code implementations17 Sep 2018 Zhuo Chen, Weisi Lin, Shiqi Wang, Ling-Yu Duan, Alex C. Kot

The recent advances of hardware technology have made the intelligent analysis equipped at the front-end with deep learning more prevailing and practical.

Data Compression Feature Compression

Attention to Head Locations for Crowd Counting

no code implementations27 Jun 2018 Youmei Zhang, Chunluan Zhou, Faliang Chang, Alex C. Kot

Occlusions, complex backgrounds, scale variations and non-uniform distributions present great challenges for crowd counting in practical applications.

Crowd Counting Density Estimation

SSNet: Scale Selection Network for Online 3D Action Prediction

no code implementations CVPR 2018 Jun Liu, Amir Shahroudy, Gang Wang, Ling-Yu Duan, Alex C. Kot

As there are significant temporal scale variations of the observed part of the ongoing action at different progress levels, we propose a novel window scale selection scheme to make our network focus on the performed part of the ongoing action and try to suppress the noise from the previous actions at each time step.

Action Recognition Temporal Action Localization

Domain Generalization With Adversarial Feature Learning

no code implementations CVPR 2018 Haoliang Li, Sinno Jialin Pan, Shiqi Wang, Alex C. Kot

In this paper, we tackle the problem of domain generalization: how to learn a generalized feature representation for an “unseen” target domain by taking the advantage of multiple seen source-domain data.

Domain Generalization

CRRN: Multi-Scale Guided Concurrent Reflection Removal Network

1 code implementation CVPR 2018 Renjie Wan, Boxin Shi, Ling-Yu Duan, Ah-Hwee Tan, Alex C. Kot

Removing the undesired reflections from images taken through the glass is of broad application to various computer vision tasks.

Reflection Removal

Dual Attention Matching Network for Context-Aware Feature Sequence based Person Re-Identification

no code implementations CVPR 2018 Jianlou Si, Honggang Zhang, Chun-Guang Li, Jason Kuen, Xiangfei Kong, Alex C. Kot, Gang Wang

Typical person re-identification (ReID) methods usually describe each pedestrian with a single feature vector and match them in a task-specific metric space.

Person Re-Identification

Benchmarking Single-Image Reflection Removal Algorithms

no code implementations ICCV 2017 Renjie Wan, Boxin Shi, Ling-Yu Duan, Ah-Hwee Tan, Alex C. Kot

Removing undesired reflections from a photo taken in front of a glass is of great importance for enhancing the efficiency of visual computing systems.

Benchmarking Reflection Removal

Global Context-Aware Attention LSTM Networks for 3D Action Recognition

no code implementations CVPR 2017 Jun Liu, Gang Wang, Ping Hu, Ling-Yu Duan, Alex C. Kot

Hence we propose a new class of LSTM network, Global Context-Aware Attention LSTM (GCA-LSTM), for 3D action recognition, which is able to selectively focus on the informative joints in the action sequence with the assistance of global contextual information.

Action Analysis One-Shot 3D Action Recognition +1

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