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Publications

Publications by CTM

2021

On Filter Generalization for Music Bandwidth Extension Using Deep Neural Networks

Authors
Sulun, S; Davies, MEP;

Publication
IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING

Abstract
In this paper, we address a subtopic of the broad domain of audio enhancement, namely musical audio bandwidth extension. We formulate the bandwidth extension problem using deep neural networks, where a band-limited signal is provided as input to the network, with the goal of reconstructing a full-bandwidth output. Our main contribution centers on the impact of the choice of low-pass filter when training and subsequently testing the network. For two different state-of-the-art deep architectures, ResNet and U-Net, we demonstrate that when the training and testing filters are matched, improvements in signal-to-noise ratio (SNR) of up to 7 dB can be obtained. However, when these filters differ, the improvement falls considerably and under some training conditions results in a lower SNR than the band-limited input. To circumvent this apparent overfitting to filter shape, we propose a data augmentation strategy which utilizes multiple low-pass filters during training and leads to improved generalization to unseen filtering conditions at test time.

2021

Guest Editorial: BIOSIG 2020 special issue on trustworthiness of person authentication

Authors
Sequeira, AF; Gomez Barrero, M; Correia, PL;

Publication
IET BIOMETRICS

Abstract
[No abstract available]

2021

My Eyes Are Up Here: Promoting Focus on Uncovered Regions in Masked Face Recognition

Authors
Neto, PC; Boutros, F; Pinto, JR; Saffari, M; Damer, N; Sequeira, AF; Cardoso, JS;

Publication
Lecture Notes in Informatics (LNI), Proceedings - Series of the Gesellschaft fur Informatik (GI)

Abstract
The recent Covid-19 pandemic and the fact that wearing masks in public is now mandatory in several countries, created challenges in the use of face recognition systems (FRS). In this work, we address the challenge of masked face recognition (MFR) and focus on evaluating the verification performance in FRS when verifying masked vs unmasked faces compared to verifying only unmasked faces. We propose a methodology that combines the traditional triplet loss and the mean squared error (MSE) intending to improve the robustness of an MFR system in the masked-unmasked comparison mode. The results obtained by our proposed method show improvements in a detailed step-wise ablation study. The conducted study showed significant performance gains induced by our proposed training paradigm and modified triplet loss on two evaluation databases.

2021

Chairs’ Message - 20<sup>th</sup> anniversary of BIOSIG

Authors
Brömme A.; Busch C.; Damer N.; Dantcheva A.; Gomez-Barrero M.; Raja K.; Rathgeb C.; Sequeira A.F.; Uhl A.;

Publication
Lecture Notes in Informatics (LNI), Proceedings - Series of the Gesellschaft fur Informatik (GI)

Abstract

2021

Chairs' Message - 20th anniversary of BIOSIG

Authors
Brömme A.; Busch C.; Damer N.; Dantcheva A.; Gomez-Barrero M.; Raja K.; Rathgeb C.; Sequeira A.F.; Uhl A.;

Publication
BIOSIG 2021 - Proceedings of the 20th International Conference of the Biometrics Special Interest Group

Abstract

2021

Selected Works from International Workshop on Biometrics and Forensics 2020

Authors
Sequeira, AF; Ross, A;

Publication
IEEE Transactions on Biometrics, Behavior, and Identity Science

Abstract

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