Search Results for author: Chun Pong Lau

Found 25 papers, 4 papers with code

Towards more transferable adversarial attack in black-box manner

no code implementations23 May 2025 Chun Tong Lei, Zhongliang Guo, Hon Chung Lee, Minh Quoc Duong, Chun Pong Lau

Traditional black-box methods have generally focused on improving the optimization framework (e. g., utilizing momentum in MI-FGSM) to enhance transferability, rather than examining the dependency on surrogate white-box model architectures.

Adversarial Attack Adversarial Purification +3

My Face Is Mine, Not Yours: Facial Protection Against Diffusion Model Face Swapping

no code implementations21 May 2025 Hon Ming Yam, Zhongliang Guo, Chun Pong Lau

The proliferation of diffusion-based deepfake technologies poses significant risks for unauthorized and unethical facial image manipulation.

Face Swapping Image Manipulation

Combining Clusters for the Approximate Randomization Test

no code implementations6 Feb 2025 Chun Pong Lau

In this paper, I develop computationally efficient procedures to combine clusters when this identification requirement does not hold.

valid

T2ICount: Enhancing Cross-modal Understanding for Zero-Shot Counting

1 code implementation CVPR 2025 Yifei Qian, Zhongliang Guo, Bowen Deng, Chun Tong Lei, Shuai Zhao, Chun Pong Lau, Xiaopeng Hong, Michael P. Pound

To address this challenge, we propose a Hierarchical Semantic Correction Module that progressively refines text-image feature alignment, and a Representational Regional Coherence Loss that provides reliable supervision signals by leveraging the cross-attention maps extracted from the denoising U-Net.

Denoising Object Counting +1

MMAD-Purify: A Precision-Optimized Framework for Efficient and Scalable Multi-Modal Attacks

no code implementations17 Oct 2024 Xinxin Liu, Zhongliang Guo, Siyuan Huang, Chun Pong Lau

With the rise of multimodality, diffusion models have emerged as powerful tools not only for generative tasks but also for various applications such as image editing, inpainting, and super-resolution.

Super-Resolution

Instant Adversarial Purification with Adversarial Consistency Distillation

no code implementations CVPR 2025 Chun Tong Lei, Hon Ming Yam, Zhongliang Guo, Chun Pong Lau

Neural networks, despite their remarkable performance in widespread applications, including image classification, are also known to be vulnerable to subtle adversarial noise.

Adversarial Purification image-classification +1

Sensitivity Analysis for Dynamic Discrete Choice Models

no code implementations29 Aug 2024 Chun Pong Lau

This paper proposes two sensitivity analysis procedures for dynamic discrete choice models with respect to the fixed parameters.

Discrete Choice Models

A Grey-box Attack against Latent Diffusion Model-based Image Editing by Posterior Collapse

no code implementations20 Aug 2024 Zhongliang Guo, Lei Fang, Jingyu Lin, Yifei Qian, Shuai Zhao, Zeyu Wang, Junhao Dong, Cunjian Chen, Ognjen Arandjelović, Chun Pong Lau

Recent advancements in generative AI, particularly Latent Diffusion Models (LDMs), have revolutionized image synthesis and manipulation.

Image Generation

Instruct2Attack: Language-Guided Semantic Adversarial Attacks

no code implementations27 Nov 2023 Jiang Liu, Chen Wei, Yuxiang Guo, Heng Yu, Alan Yuille, Soheil Feizi, Chun Pong Lau, Rama Chellappa

We propose Instruct2Attack (I2A), a language-guided semantic attack that generates semantically meaningful perturbations according to free-form language instructions.

Whole-body Detection, Recognition and Identification at Altitude and Range

no code implementations9 Nov 2023 Siyuan Huang, Ram Prabhakar Kathirvel, Chun Pong Lau, Rama Chellappa

In this paper, we address the challenging task of whole-body biometric detection, recognition, and identification at distances of up to 500m and large pitch angles of up to 50 degree.

Body Detection TAR

Distillation-guided Representation Learning for Unconstrained Gait Recognition

no code implementations27 Jul 2023 Yuxiang Guo, Siyuan Huang, Ram Prabhakar, Chun Pong Lau, Rama Chellappa, Cheng Peng

Gait recognition holds the promise of robustly identifying subjects based on walking patterns instead of appearance information.

Gait Recognition Representation Learning

DiffProtect: Generate Adversarial Examples with Diffusion Models for Facial Privacy Protection

1 code implementation23 May 2023 Jiang Liu, Chun Pong Lau, Rama Chellappa

In this work, we ask: can diffusion models be used to generate adversarial examples to improve both visual quality and attack performance?

Image Generation

Attribute-Guided Encryption with Facial Texture Masking

no code implementations22 May 2023 Chun Pong Lau, Jiang Liu, Rama Chellappa

In this paper, we propose Attribute Guided Encryption with Facial Texture Masking (AGE-FTM) that performs a dual manifold adversarial attack on FR systems to achieve both good visual quality and high black box attack success rates.

Adversarial Attack Attribute +1

Multi-Modal Human Authentication Using Silhouettes, Gait and RGB

no code implementations8 Oct 2022 Yuxiang Guo, Cheng Peng, Chun Pong Lau, Rama Chellappa

In this work, we propose Dual-Modal Ensemble (DME), which combines both RGB and silhouette data to achieve more robust performances for indoor and outdoor whole-body based recognition.

Gait Recognition

Segment and Complete: Defending Object Detectors against Adversarial Patch Attacks with Robust Patch Detection

1 code implementation CVPR 2022 Jiang Liu, Alexander Levine, Chun Pong Lau, Rama Chellappa, Soheil Feizi

In addition, we design a robust shape completion algorithm, which is guaranteed to remove the entire patch from the images if the outputs of the patch segmenter are within a certain Hamming distance of the ground-truth patch masks.

Adversarial Attack Detection Adversarial Defense +5

Identification of Attack-Specific Signatures in Adversarial Examples

no code implementations13 Oct 2021 Hossein Souri, Pirazh Khorramshahi, Chun Pong Lau, Micah Goldblum, Rama Chellappa

The adversarial attack literature contains a myriad of algorithms for crafting perturbations which yield pathological behavior in neural networks.

Adversarial Attack

Dual Manifold Adversarial Robustness: Defense against Lp and non-Lp Adversarial Attacks

no code implementations NeurIPS 2020 Wei-An Lin, Chun Pong Lau, Alexander Levine, Rama Chellappa, Soheil Feizi

Using OM-ImageNet, we first show that adversarial training in the latent space of images improves both standard accuracy and robustness to on-manifold attacks.

Adversarial Robustness

ATFaceGAN: Single Face Image Restoration and Recognition from Atmospheric Turbulence

no code implementations7 Oct 2019 Chun Pong Lau, Hossein Souri, Rama Chellappa

To mitigate the degradation due to turbulence which includes deformation and blur, we propose a generative single frame restoration algorithm which disentangles the blur and deformation due to turbulence and reconstructs a restored image.

Disentanglement Face Recognition +1

Subsampled Turbulence Removal Network

no code implementations12 Jul 2018 Wai Ho Chak, Chun Pong Lau, Lok Ming Lui

Instead of requiring a massive training sample size in deep networks, we purpose a training strategy that is based on a new data augmentation method to model turbulence from a relatively small dataset.

Data Augmentation

Variational models for joint subsampling and reconstruction of turbulence-degraded images

no code implementations8 Dec 2017 Chun Pong Lau, Yu Hin Lai, Lok Ming Lui

The energy consists of a fidelity term measuring the discrepancy between the extracted image and the subsampled frames, as well as regularization terms on the extracted image and the subsample.

Image retargeting via Beltrami representation

no code implementations11 Oct 2017 Chun Pong Lau, Chun Pang Yung, Lok Ming Lui

In this paper, we propose a simple and yet effective method to resize an image, which preserves the geometry of the important content, using the Beltrami representation.

Image Retargeting

Restoration of Atmospheric Turbulence-distorted Images via RPCA and Quasiconformal Maps

no code implementations11 Apr 2017 Chun Pong Lau, Yu Hin Lai, Lok Ming Lui

The subsampled image sequence is then stabilized by applying the Robust Principal Component Analysis (RPCA) on the deformation fields between image frames and warping the image frames by a quasiconformal map associated with the low-rank part of the deformation matrix.

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