2021
Autores
Sulun, S; Davies, MEP;
Publicação
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
Autores
Sequeira, AF; Gomez Barrero, M; Correia, PL;
Publicação
IET BIOMETRICS
Abstract
[No abstract available]
2021
Autores
Neto, PC; Boutros, F; Pinto, JR; Saffari, M; Damer, N; Sequeira, AF; Cardoso, JS;
Publicação
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
Autores
Brömme A.; Busch C.; Damer N.; Dantcheva A.; Gomez-Barrero M.; Raja K.; Rathgeb C.; Sequeira A.F.; Uhl A.;
Publicação
Lecture Notes in Informatics (LNI), Proceedings - Series of the Gesellschaft fur Informatik (GI)
Abstract
2021
Autores
Brömme A.; Busch C.; Damer N.; Dantcheva A.; Gomez-Barrero M.; Raja K.; Rathgeb C.; Sequeira A.F.; Uhl A.;
Publicação
BIOSIG 2021 - Proceedings of the 20th International Conference of the Biometrics Special Interest Group
Abstract
2021
Autores
Sequeira, AF; Ross, A;
Publicação
IEEE Transactions on Biometrics, Behavior, and Identity Science
Abstract
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