Ana Sequeira

Dr. Ana Sequeira

INESC TEC, Porto, Portugal
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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10 October 2022
Verified
Conference Paper
Closed access
MHMarco Huber
Marco Huber
FBFadi Boutros
Fadi Boutros
ALAnh Thi Luu
Anh Thi Luu
KRKiran Raja
Kiran Raja
RRRaghavendra Ramachandra
Raghavendra Ramachandra
VSVitomir Struc
Vitomir Struc
This paper presents a summary of the Competition on Face Morphing Attack Detection Based on Privacy-aware Synthetic Training Data (SYN-MAD) held at the 2022 In-ternational Joint Conference on Biometrics (IJCB 2022). The competition attracted a total of 12 participating teams, both from academia and industry and present in 11 differ-ent countries. In the end, seven valid submissions were submitted by the participating teams and evaluated by the organizers. The competition was held to present and at-tract solutions that deal with detecting face morphing at-tacks while protecting people's privacy for ethical and le-gal reasons. To ensure this, the training data was limited to synthetic data provided by the organizers. The submitted solutions presented innovations that led to out-performing the considered baseline in many experimental settings. The evaluation benchmark is now available at: https://github.com/marcohuber/SYN-MAD-2022.

16 August 2022 in IEEE Access
Verified
Journal Article
Open access
PNPedro C. Neto
Pedro C. Neto
JPJoao Ribeiro Pinto
Joao Ribeiro Pinto
FBFadi Boutros
Fadi Boutros
NDNaser Damer
Naser Damer
Ana SequeiraAna Sequeira
Ana Sequeira
JCJaime Cardoso
Jaime Cardoso
Over the years, the evolution of face recognition (FR) algorithms has been steep and accelerated by a myriad of factors. Motivated by the unexpected elements found in real-world scenarios, researchers have investigated and developed a number of methods for occluded face recognition (OFR). However, due to the SarS-Cov2 pandemic, masked face recognition (MFR) research branched from OFR and became a hot and urgent research challenge. Due to time and data constraints, these models followed different and novel approaches to handle lower face occlusions, i.e., face masks. Hence, this study aims to evaluate the different approaches followed for both MFR and OFR, find linked details about the two conceptually similar research directions and understand future directions for both topics. For this analysis, several occluded and face recognition algorithms from the literature are studied. First, they are evaluated in the task that they were trained on, but also on the other. These methods were picked accordingly to the novelty of their approach, proven state-of-the-art results, and publicly available source code. We present quantitative results on 4 occluded and 5 masked FR datasets, and a qualitative analysis of several MFR and OFR models on the Occ-LFW dataset. The analysis presented, sustain the interoperable deployability of MFR methods on OFR datasets, when the occlusions are of a reasonable size. Thus, solutions proposed for MFR can be effectively deployed for general OFR.

1 September 2016
Verified
Conference Paper
Closed access
Ana SequeiraAna Sequeira
Ana Sequeira
LCLulu Chen
Lulu Chen
PWPeter Wild
Peter Wild
JFJames Ferryman
James Ferryman
FAFernando Alonso-Fernandez
Fernando Alonso-Fernandez
JBJoseph Bigun
Joseph Bigun
This work presents a novel dual-spectrum database containing both iris and periocular images synchronously captured from a distance and within a realistic indoor environment. This database was used in the 1st Cross-Spectrum Iris/Periocular Recognition Competition (Cross-Eyed 2016). This competition aimed at recording recent advances in cross- spectrum iris and periocular recognition. Six submissions were evaluated for cross-spectrum periocular recognition, and three for iris recognition. The submitted algorithms are briefly introduced. Detailed results are reported in this paper, and comparison of the results is discussed.

1 October 2017
Verified
Conference Paper
Closed access
Ana SequeiraAna Sequeira
Ana Sequeira
LCLulu Chen
Lulu Chen
JFJames Ferryman
James Ferryman
PWPeter Wild
Peter Wild
FAFernando Alonso-Fernandez
Fernando Alonso-Fernandez
VKVivek Kanhangad
Vivek Kanhangad
This work presents the 2nd Cross-Spectrum Iris/Periocular Recognition Competition (Cross-Eyed2017). The main goal of the competition is to promote and evaluate advances in cross-spectrum iris and periocular recognition. This second edition registered an increase in the participation numbers ranging from academia to industry: five teams submitted twelve methods for the periocular task and five for the iris task. The benchmark dataset is an enlarged version of the dual-spectrum database containing both iris and periocular images synchronously captured from a distance and within a realistic indoor environment. The evaluation was performed on an undisclosed test-set. Methodology, tested algorithms, and obtained results are reported in this paper identifying the remaining challenges in path forward.

1 September 2014
Verified
Conference Paper
Closed access
Ana SequeiraAna Sequeira
Ana Sequeira
HOHelder Oliveira
Helder Oliveira
JMJoão Pedro Monteiro
João Pedro Monteiro
JCJaime Cardoso
Jaime Cardoso
Biometric systems based on iris are vulnerable to several attacks, particularly direct attacks consisting on the presentation of a fake iris to the sensor. The development of iris liveness detection techniques is crucial for the deployment of iris biometric applications in daily life specially in the mobile biometric field. The 1 st Mobile Iris Liveness Detection Competition (MobILive) was organized in the context of IJCB2014 in order to record recent advances in iris liveness detection. The goal for (MobILive) was to contribute to the state of the art of this particular subject. This competition covered the most common and simple spoofing attack in which printed images from an authorized user are presented to the sensor by a non-authorized user in order to obtain access. The benchmark dataset was the MobBIOfake database which is composed by a set of 800 iris images and its corresponding fake copies (obtained from printed images of the original ones captured with the same handheld device and in similar conditions). In this paper we present a brief description of the methods and the results achieved by the six participants in the competition.

1 December 2016
Verified
Conference Paper
Closed access
Ana SequeiraAna Sequeira
Ana Sequeira
STShejin Thavalengal
Shejin Thavalengal
JFJames Ferryman
James Ferryman
Peter CorcoranPeter Corcoran
Peter Corcoran
JCJaime Cardoso
Jaime Cardoso
Iris liveness detection methods have been developed to overcome the vulnerability of iris biometric systems to spoofing attacks. In the literature, it is typically assumed that a known attack modality will be perpetrated. Then liveness models are designed using labelled samples from both real/live and fake/spoof distributions, the latter derived from the assumed attack modality. In this work it is argued that a comprehensive modelling of the spoof samples is not possible in a real-world scenario where the attack modality cannot be known with a high degree of certainty. In fact making this assumption will render the liveness detection system more vulnerable to attacks that were not included in the original training. To provide a more realistic evaluation, this work proposes: a) testing the binary models with unknown spoof samples that were not present in the training step; b) the use of a single-class classification designing the classifier by modelling only the distribution of live samples. The results obtained support the assertion that many evaluation methods from the literature are misleading and may lead to optimistic estimates of the robustness of liveness detection in practical use cases.