Chenqi Kong

Dr. Chenqi Kong

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 April 2022 in IEEE Transactions on Information Forensics and Security
Verified
Journal Article
Closed access
CKChenqi Kong
Chenqi Kong
BCBaoliang Chen
Baoliang Chen
HLHaoliang Li
Haoliang Li
SWShiqi Wang
Shiqi Wang
ARAnderson Rocha
Anderson Rocha
KWONG Tak Wu SamKWONG Tak Wu Sam
KWONG Tak Wu Sam
The technological advancements of deep learning have enabled sophisticated face manipulation schemes, raising severe trust issues and security concerns in modern society. Generally speaking, detecting manipulated faces and locating the potentially altered regions are challenging tasks. Herein, we propose a conceptually simple but effective method to efficiently detect forged faces in an image while simultaneously locating the manipulated regions. The proposed scheme relies on a segmentation map that delivers meaningful high-level semantic information clues about the image. Furthermore, a noise map is estimated, playing a complementary role in capturing low-level clues and subsequently empowering decision-making. Finally, the features from these two modules are combined to distinguish fake faces. Extensive experiments show that the proposed model achieves state-of-the-art detection accuracy and remarkable localization performance.

13 November 2023 in IEEE Transactions on Information Forensics and Security
Verified
Journal Article
Closed access
ALAnwei Luo
Anwei Luo
CKChenqi Kong
Chenqi Kong
JHJiwu Huang
Jiwu Huang
YHYongjian Hu
Yongjian Hu
XKXiangui Kang
Xiangui Kang
AKAlex C. Kot
Alex C. Kot
Face forgery detection is essential in combating malicious digital face attacks. Previous methods mainly rely on prior expert knowledge to capture specific forgery clues, such as noise patterns, blending boundaries, and frequency artifacts. However, these methods tend to get trapped in local optima, resulting in limited robustness and generalization capability. To address these issues, we propose a novel Critical Forgery Mining (CFM) framework, which can be flexibly assembled with various backbones to boost their generalization and robustness performance. Specifically, we first build a fine-grained triplet and suppress specific forgery traces through prior knowledge-agnostic data augmentation. Subsequently, we propose a fine-grained relation learning prototype to mine critical information in forgeries through instance and local similarity-aware losses. Moreover, we design a novel progressive learning controller to guide the model to focus on principal feature components, enabling it to learn critical forgery features in a coarse-to-fine manner. The proposed method achieves state-of-the-art forgery detection performance under various challenging evaluation settings. The source code is available at: https://github.com/LoveSiameseCat/CFM .

11 February 2025 in IEEE Transactions on Pattern Analysis and Machine Intelligence
Verified
Journal Article
Closed access
CKChenqi Kong
Chenqi Kong
ALAnwei Luo
Anwei Luo
SWShiqi Wang
Shiqi Wang
HLHaoliang Li
Haoliang Li
ARAnderson Rocha
Anderson Rocha
AKAlex C. Kot
Alex C. Kot
Digital image forensics plays a crucial role in image authentication and manipulation localization. Despite the progress powered by deep neural networks, existing forgery localization methodologies exhibit limitations when deployed to unseen datasets and perturbed images (i.e., lack of generalization and robustness to real-world applications). To circumvent these problems and aid image integrity, this paper presents a generalized and robust manipulation localization model through the analysis of pixel inconsistency artifacts. The rationale is grounded on the observation that most image signal processors (ISP) involve the demosaicing process, which introduces pixel correlations in pristine images. Moreover, manipulating operations, including splicing, copy-move, and inpainting, directly affect such pixel regularity. We, therefore, first split the input image into several blocks and design masked self-attention mechanisms to model the global pixel dependency in input images. Simultaneously, we optimize another local pixel dependency stream to mine local manipulation clues within input forgery images. In addition, we design novel Learning-to-Weight Modules (LWM) to combine features from the two streams, thereby enhancing the final forgery localization performance. To improve the training process, we propose a novel Pixel-Inconsistency Data Augmentation (PIDA) strategy, driving the model to focus on capturing inherent pixel-level artifacts instead of mining semantic forgery traces. This work establishes a comprehensive benchmark integrating 16 representative detection models across 12 datasets. Extensive experiments show that our method successfully extracts inherent pixel-inconsistency forgery fingerprints and achieve state-of-the-art generalization and robustness performances in image manipulation localization.

26 August 2022 in IEEE Transactions on Information Forensics and Security
Verified
Journal Article
Closed access
CKChenqi Kong
Chenqi Kong
KZKexin Zheng
Kexin Zheng
SWShiqi Wang
Shiqi Wang
ARAnderson Rocha
Anderson Rocha
HLHaoliang Li
Haoliang Li
2D face presentation attacks are one of the most notorious and pervasive face spoofing types, which have caused pressing security issues to facial authentication systems. While RGB-based face anti-spoofing (FAS) models have proven to counter the face spoofing attack effectively, most existing FAS models suffer from the overfitting problem (i.e., lack generalization capability to data collected from an unseen environment). Recently, many models have been devoted to capturing auxiliary information ( $e.g$ ., depth and infrared maps) to achieve a more robust face liveness detection performance. However, these methods require expensive sensors and cost extra hardware to capture the specific modality information, limiting their applications in practical scenarios. To tackle these problems, we devise a novel and cost-effective FAS system based on the acoustic modality, named Echo-FAS, which employs the crafted acoustic signal as the probe to perform face liveness detection. We first propose to build a large-scale, high-diversity, and acoustic-based FAS database, Echo-Spoof. Then, based upon Echo-Spoof, we propose designing a novel two-branch framework that combines the global and local frequency clues of input signals to distinguish inputs, live vs. spoofing faces accurately. The devised Echo-FAS comprises the following three merits: (1) It only needs one available speaker and microphone as sensors while not requiring any expensive hardware; (2) It can successfully capture the 3D geometrical information of input queries and achieve a remarkable face anti-spoofing performance; and (3) It can be handily allied with other RGB-based FAS models to mitigate the overfitting problem in the RGB modality and make the FAS model more accurate and robust. Our proposed Echo-FAS provides new insights regarding the development of FAS systems for mobile devices.

29 August 2025 in IEEE Transactions on Dependable and Secure Computing
Verified
Journal Article
Closed access
CKChenqi Kong
Chenqi Kong
ALAnwei Luo
Anwei Luo
PBPeijun Bao
Peijun Bao
YYYi Yu
Yi Yu
HLHaoliang Li
Haoliang Li
AKAlex C. Kot
Alex C. Kot
Deepfakes have recently raised significant trust issues and security concerns among the public. Compared to CNN-based face forgery detectors, ViT-based methods take advantage of the expressivity of transformers, achieving superior detection performance. However, these approaches still exhibit the following limitations: (1) Fully fine-tuning ViT-based models from ImageNet weights demands substantial computational and storage resources; (2) ViT-based methods struggle to capture local forgery clues, leading to model bias; (3) These methods limit their scope on only one or few face forgery features, resulting in limited generalizability. To tackle these challenges, this work introduces Mixture-of-Experts modules for Face Forgery Detection (MoE-FFD), a generalized yet parameter-efficient ViT-based approach. MoE-FFD only updates lightweight Low-Rank Adaptation (LoRA) and Adapter layers while keeping the ViT backbone frozen, thereby achieving parameter-efficient training. Moreover, MoE-FFD leverages the expressivity of transformers and local priors of CNNs to simultaneously extract global and local forgery clues. Additionally, novel MoE modules are designed to scale the model's capacity and smartly select optimal forgery experts, further enhancing forgery detection performance. Our proposed learning scheme can be seamlessly adapted to various transformer backbones in a plug-and-play manner. Extensive experimental results demonstrate that the proposed method achieves state-of-the-art face forgery detection performance with significantly reduced parameter overhead in cross-dataset, cross-manipulation, and robustness evaluations. Our ablation studies further validate the effectiveness of the designed components and the proposed learning scheme. The code is available at: https://github.com/LoveSiameseCat/MoE-FFD.

28 June 2024 in IEEE Transactions on Information Forensics and Security
Verified
Journal Article
Closed access
RCRizhao Cai
Rizhao Cai
ZYZitong Yu
Zitong Yu
CKChenqi Kong
Chenqi Kong
HLHaoliang Li
Haoliang Li
CCChangsheng Chen
Changsheng Chen
AKAlex C. Kot
Alex C. Kot
Face Anti-Spoofing (FAS) aims to detect malicious attempts to invade a face recognition system by presenting spoofed faces. State-of-the-art FAS techniques predominantly rely on deep learning models but their cross-domain generalization capabilities are often hindered by the domain shift problem, which arises due to different distributions between training and testing data. In this study, we develop a generalized FAS method under the Efficient Parameter Transfer Learning (EPTL) paradigm, where we adapt the pre-trained Vision Transformer models for the FAS task. During training, the adapter modules are inserted into the pre-trained ViT model, and the adapters are updated while other pre-trained parameters remain fixed. We find the limitations of previous vanilla adapters in that they are based on linear layers, which lack a spoofing-aware inductive bias and thus restrict the cross-domain generalization. To address this limitation and achieve cross-domain generalized FAS, we propose a novel Statistical Adapter (S-Adapter) that gathers local discriminative and statistical information from localized token histograms. To further improve the generalization of the statistical tokens, we propose a novel Token Style Regularization (TSR), which aims to reduce domain style variance by regularizing Gram matrices extracted from tokens across different domains. Our experimental results demonstrate that our proposed S-Adapter and TSR provide significant benefits in both zero-shot and few-shot cross-domain testing, outperforming state-of-the-art methods on several benchmark tests. We will release the source code upon acceptance.