1,050 research outputs found
Learning One Class Representations for Face Presentation Attack Detection using Multi-channel Convolutional Neural Networks
Face recognition has evolved as a widely used biometric modality. However,
its vulnerability against presentation attacks poses a significant security
threat. Though presentation attack detection (PAD) methods try to address this
issue, they often fail in generalizing to unseen attacks. In this work, we
propose a new framework for PAD using a one-class classifier, where the
representation used is learned with a Multi-Channel Convolutional Neural
Network (MCCNN). A novel loss function is introduced, which forces the network
to learn a compact embedding for bonafide class while being far from the
representation of attacks. A one-class Gaussian Mixture Model is used on top of
these embeddings for the PAD task. The proposed framework introduces a novel
approach to learn a robust PAD system from bonafide and available (known)
attack classes. This is particularly important as collecting bonafide data and
simpler attacks are much easier than collecting a wide variety of expensive
attacks. The proposed system is evaluated on the publicly available WMCA
multi-channel face PAD database, which contains a wide variety of 2D and 3D
attacks. Further, we have performed experiments with MLFP and SiW-M datasets
using RGB channels only. Superior performance in unseen attack protocols shows
the effectiveness of the proposed approach. Software, data, and protocols to
reproduce the results are made available publicly.Comment: 15 page
On the Effectiveness of Vision Transformers for Zero-shot Face Anti-Spoofing
The vulnerability of face recognition systems to presentation attacks has
limited their application in security-critical scenarios. Automatic methods of
detecting such malicious attempts are essential for the safe use of facial
recognition technology. Although various methods have been suggested for
detecting such attacks, most of them over-fit the training set and fail in
generalizing to unseen attacks and environments. In this work, we use transfer
learning from the vision transformer model for the zero-shot anti-spoofing
task. The effectiveness of the proposed approach is demonstrated through
experiments in publicly available datasets. The proposed approach outperforms
the state-of-the-art methods in the zero-shot protocols in the HQ-WMCA and
SiW-M datasets by a large margin. Besides, the model achieves a significant
boost in cross-database performance as well.Comment: 8 pages, 3 figures, Accepted for Publication in IJCB202
Bridging the Gap: Heterogeneous Face Recognition with Conditional Adaptive Instance Modulation
Heterogeneous Face Recognition (HFR) aims to match face images across
different domains, such as thermal and visible spectra, expanding the
applicability of Face Recognition (FR) systems to challenging scenarios.
However, the domain gap and limited availability of large-scale datasets in the
target domain make training robust and invariant HFR models from scratch
difficult. In this work, we treat different modalities as distinct styles and
propose a framework to adapt feature maps, bridging the domain gap. We
introduce a novel Conditional Adaptive Instance Modulation (CAIM) module that
can be integrated into pre-trained FR networks, transforming them into HFR
networks. The CAIM block modulates intermediate feature maps, to adapt the
style of the target modality effectively bridging the domain gap. Our proposed
method allows for end-to-end training with a minimal number of paired samples.
We extensively evaluate our approach on multiple challenging benchmarks,
demonstrating superior performance compared to state-of-the-art methods. The
source code and protocols for reproducing the findings will be made publicly
available.Comment: Accepted for publication in IJCB 202
Molecular structure, mechanical behavior and failure mechanism of the C-terminal cross-link domain in type I collagen
Collagen is a key constituent in structural materials found in biology, including bone, tendon, skin and blood vessels. Here we report a first molecular level model of an entire overlap region of a C-terminal cross-linked type I collagen assembly and carry out a nanomechanical characterization based on large-scale molecular dynamics simulation in explicit water solvent. Our results show that the deformation mechanism and strength of the structure are greatly affected by the presence of the cross-link, and by the specific loading condition of how the stretching is applied. We find that the presence of a cross-link results in greater strength during deformation as complete intermolecular slip is prevented, and thereby particularly affects larger deformation levels. Conversely, the lack of a cross-link results in the onset of intermolecular sliding during deformation and as a result an overall weaker structure is obtained. Through a detailed analysis of the distribution of deformation by calculating the molecular strain we show that the location of largest strains does not occur around the covalent bonding region, but is found in regions further away from this location. The insight developed from understanding collagenous materials from a fundamental molecular level upwards could play a role in advancing our understanding of physiological and disease states of connective tissues, and also enable the development of new scaffolding material for applications in regenerative medicine and biologically inspired materials
Deep Models and Shortwave Infrared Information to Detect Face Presentation Attacks
This paper addresses the problem of face presentation attack detection using
different image modalities. In particular, the usage of short wave infrared
(SWIR) imaging is considered. Face presentation attack detection is performed
using recent models based on Convolutional Neural Networks using only carefully
selected SWIR image differences as input. Conducted experiments show superior
performance over similar models acting on either color images or on a
combination of different modalities (visible, NIR, thermal and depth), as well
as on a SVM-based classifier acting on SWIR image differences. Experiments have
been carried on a new public and freely available database, containing a wide
variety of attacks. Video sequences have been recorded thanks to several
sensors resulting in 14 different streams in the visible, NIR, SWIR and thermal
spectra, as well as depth data. The best proposed approach is able to almost
perfectly detect all impersonation attacks while ensuring low bonafide
classification errors. On the other hand, obtained results show that
obfuscation attacks are more difficult to detect. We hope that the proposed
database will foster research on this challenging problem. Finally, all the
code and instructions to reproduce presented experiments is made available to
the research community
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