35 research outputs found
Cross-Spectral Periocular Recognition with Conditional Adversarial Networks
This work addresses the challenge of comparing periocular images captured in
different spectra, which is known to produce significant drops in performance
in comparison to operating in the same spectrum. We propose the use of
Conditional Generative Adversarial Networks, trained to con-vert periocular
images between visible and near-infrared spectra, so that biometric
verification is carried out in the same spectrum. The proposed setup allows the
use of existing feature methods typically optimized to operate in a single
spectrum. Recognition experiments are done using a number of off-the-shelf
periocular comparators based both on hand-crafted features and CNN descriptors.
Using the Hong Kong Polytechnic University Cross-Spectral Iris Images Database
(PolyU) as benchmark dataset, our experiments show that cross-spectral
performance is substantially improved if both images are converted to the same
spectrum, in comparison to matching features extracted from images in different
spectra. In addition to this, we fine-tune a CNN based on the ResNet50
architecture, obtaining a cross-spectral periocular performance of EER=1%, and
GAR>99% @ FAR=1%, which is comparable to the state-of-the-art with the PolyU
database.Comment: Accepted for publication at 2020 International Joint Conference on
Biometrics (IJCB 2020
Periocular Biometrics: A Modality for Unconstrained Scenarios
Periocular refers to the region of the face that surrounds the eye socket.
This is a feature-rich area that can be used by itself to determine the
identity of an individual. It is especially useful when the iris or the face
cannot be reliably acquired. This can be the case of unconstrained or
uncooperative scenarios, where the face may appear partially occluded, or the
subject-to-camera distance may be high. However, it has received revived
attention during the pandemic due to masked faces, leaving the ocular region as
the only visible facial area, even in controlled scenarios. This paper
discusses the state-of-the-art of periocular biometrics, giving an overall
framework of its most significant research aspects
A Reminiscence of ”Mastermind”: Iris/Periocular Biometrics by ”In-Set” CNN Iterative Analysis
Convolutional neural networks (CNNs) have
emerged as the most popular classification models in biometrics
research. Under the discriminative paradigm of pattern
recognition, CNNs are used typically in one of two ways: 1)
verification mode (”are samples from the same person?”), where
pairs of images are provided to the network to distinguish
between genuine and impostor instances; and 2) identification
mode (”whom is this sample from?”), where appropriate feature
representations that map images to identities are found. This
paper postulates a novel mode for using CNNs in biometric
identification, by learning models that answer to the question ”is
the query’s identity among this set?”. The insight is a reminiscence
of the classical Mastermind game: by iteratively analysing the
network responses when multiple random samples of k gallery
elements are compared to the query, we obtain weakly correlated
matching scores that - altogether - provide solid cues to infer
the most likely identity. In this setting, identification is regarded
as a variable selection and regularization problem, with sparse
linear regression techniques being used to infer the matching
probability with respect to each gallery identity. As main strength,
this strategy is highly robust to outlier matching scores, which
are known to be a primary error source in biometric recognition.
Our experiments were carried out in full versions of two
well known irises near-infrared (CASIA-IrisV4-Thousand) and
periocular visible wavelength (UBIRIS.v2) datasets, and confirm
that recognition performance can be solidly boosted-up by the
proposed algorithm, when compared to the traditional working
modes of CNNs in biometrics.info:eu-repo/semantics/publishedVersio
One-Shot Learning for Periocular Recognition: Exploring the Effect of Domain Adaptation and Data Bias on Deep Representations
One weakness of machine-learning algorithms is the need to train the models
for a new task. This presents a specific challenge for biometric recognition
due to the dynamic nature of databases and, in some instances, the reliance on
subject collaboration for data collection. In this paper, we investigate the
behavior of deep representations in widely used CNN models under extreme data
scarcity for One-Shot periocular recognition, a biometric recognition task. We
analyze the outputs of CNN layers as identity-representing feature vectors. We
examine the impact of Domain Adaptation on the network layers' output for
unseen data and evaluate the method's robustness concerning data normalization
and generalization of the best-performing layer. We improved state-of-the-art
results that made use of networks trained with biometric datasets with millions
of images and fine-tuned for the target periocular dataset by utilizing
out-of-the-box CNNs trained for the ImageNet Recognition Challenge and standard
computer vision algorithms. For example, for the Cross-Eyed dataset, we could
reduce the EER by 67% and 79% (from 1.70% and 3.41% to 0.56% and 0.71%) in the
Close-World and Open-World protocols, respectively, for the periocular case. We
also demonstrate that traditional algorithms like SIFT can outperform CNNs in
situations with limited data or scenarios where the network has not been
trained with the test classes like the Open-World mode. SIFT alone was able to
reduce the EER by 64% and 71.6% (from 1.7% and 3.41% to 0.6% and 0.97%) for
Cross-Eyed in the Close-World and Open-World protocols, respectively, and a
reduction of 4.6% (from 3.94% to 3.76%) in the PolyU database for the
Open-World and single biometric case.Comment: Submitted preprint to IEE Acces
Biometric presentation attack detection: beyond the visible spectrum
The increased need for unattended authentication in
multiple scenarios has motivated a wide deployment of biometric
systems in the last few years. This has in turn led to the
disclosure of security concerns specifically related to biometric
systems. Among them, presentation attacks (PAs, i.e., attempts
to log into the system with a fake biometric characteristic or
presentation attack instrument) pose a severe threat to the
security of the system: any person could eventually fabricate
or order a gummy finger or face mask to impersonate someone
else. In this context, we present a novel fingerprint presentation
attack detection (PAD) scheme based on i) a new capture device
able to acquire images within the short wave infrared (SWIR)
spectrum, and i i) an in-depth analysis of several state-of-theart
techniques based on both handcrafted and deep learning
features. The approach is evaluated on a database comprising
over 4700 samples, stemming from 562 different subjects and
35 different presentation attack instrument (PAI) species. The
results show the soundness of the proposed approach with a
detection equal error rate (D-EER) as low as 1.35% even in a
realistic scenario where five different PAI species are considered
only for testing purposes (i.e., unknown attacks