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Publications

Publications by CTM

2018

Cross-eyed 2017: Cross-spectral iris/periocular recognition competition

Authors
Sequeira A.F.; Chen L.; Ferryman J.; Wild P.; Alonso-Fernandez F.; Bigun J.; Raja K.B.; Raghavendra R.; Busch C.; De Freitas Pereira T.; Marcel S.; Behera S.S.; Gour M.; Kanhangad V.;

Publication
IEEE International Joint Conference on Biometrics, IJCB 2017

Abstract
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.

2018

Mobile NIR iris recognition: Identifying problems and solutions

Authors
Hofbauer H.; Jalilian E.; Sequeira A.F.; Ferryman J.; Uhl A.;

Publication
2018 IEEE 9th International Conference on Biometrics Theory, Applications and Systems, BTAS 2018

Abstract
The spread of biometric applications in mobile devices handled by untrained users opened the door to sources of noise in mobile iris recognition such as larger extent of rotation in the capture and more off-angle imagery not found so extensively in more constrained acquisition settings. As a result of the limitations of the methods in handling such large degrees of freedom there is often an increase in segmentation errors. In this work, a new near-infrared iris dataset captured with a mobile device is evaluated to analyse, in particular, the rotation observed in images and its impact on segmentation and biometric recognition accuracy. For this study a (manually annotated) ground truth segmentation was used which will be published in tandem with the paper. Similarly to most research challenges in biometrics and computer vision in general, deep learning techniques are proving to outperform classical methods in segmentation methods. The utilization of parameterized CNN-based iris segmentations in biometric recognition is a new but promising field. The results presented show how this CNN-based approach outperformed the segmentation traditional methods with respect to overall recognition accuracy for the dataset under investigation.

2018

PROTECT Multimodal DB: Fusion evaluation on a novel multimodal biometrics dataset envisaging Border Control

Authors
Sequeira, AF; Chen, L; Ferryman, J; Galdi, C; Chiesa, V; Dugelay, JL; Maik, P; Gmitrowicz, P; Szklarski, L; Prommegger, B; Kauba, C; Kirchgasser, S; Uhl, A; Grudzie, A; Kowalski, M;

Publication
2018 International Conference of the Biometrics Special Interest Group, BIOSIG 2018

Abstract
This work presents a novel multimodal database comprising 3D face, 2D face, thermal face, visible iris, finger and hand veins, voice and anthropometrics. This dataset will constitute a valuable resource to the field with its number and variety of biometric traits. Acquired in the context of the EU PROTECT project, the dataset allows several combinations of biometric traits and envisages applications such as border control. Based upon the results of the unimodal data, a fusion scheme was applied to ascertain the recognition potential of combining these biometric traits in a multimodal approach. Due to the variability on the discriminative power of the traits, a leave the n-best out fusion technique was applied to obtain different recognition results. © 2018 Gesellschaft fuer Informatik.

2018

On the Use of Natural User Interfaces in Physical Rehabilitation: A Web-based Application for Patients with Hip Prosthesis

Authors
Rybarczyk, Y; Cointe, C; Goncalves, T; Minhoto, V; Deters, JK; Villarreal, S; Gonzalo, AA; Baldeon, J; Esparza, D;

Publication
JOURNAL OF SCIENCE AND TECHNOLOGY OF THE ARTS

Abstract
This study aims to develop a telemedicine platform for self-motor rehabilitation and remote monitoring by health professionals, in order to enhance recovery in patients after hip replacement. The implementation of such a technology is justified by medical (improvement of the recovery process by the possibility to perform rehabilitation exercises more frequently), economic (reduction of the number of medical appointments and the time patients spend at the hospital), mobility (diminution of the transportation to and from the hospital) and ethics (healthcare democratization and increased empowerment of the patient) purposes. The Kinect camera is used as a Natural User Interface to capture the physical exercises performed at home by the patients. The quality of the movement is evaluated in real-time by an assessment module implemented according to a Hidden-Markov Model approach. The results show a high accuracy in the evaluation of the movements (92% of correct classification). Finally, the usability of the platform is tested through the System Usability Scale (SUS). The overall SUS score is 81 out of 100, which suggests a good usability of the Web application. Further work will focus on the development of additional functionalities and an evaluation of the impact of the platform on the recovery process.

2018

Supervised learning methods for pathological arterial pulse wave differentiation: A SVM and neural networks approach

Authors
Paiva, JS; Cardoso, J; Pereira, T;

Publication
INTERNATIONAL JOURNAL OF MEDICAL INFORMATICS

Abstract
Objective: The main goal of this study was to develop an automatic method based on supervised learning methods, able to distinguish healthy from pathologic arterial pulse wave (APW), and those two from noisy waveforms (non-relevant segments of the signal), from the data acquired during a clinical examination with a novel optical system. Materials and methods: The APW dataset analysed was composed by signals acquired in a clinical environment from a total of 213 subjects, including healthy volunteers and non-healthy patients. The signals were parameterised by means of 39 pulse features: morphologic, time domain statistics, cross-correlation features, wavelet features. Multiclass Support Vector Machine Recursive Feature Elimination (SVM RFE) method was used to select the most relevant features. A comparative study was performed in order to evaluate the performance of the two classifiers: Support Vector Machine (SVM) and Artificial Neural Network (ANN). Results and discussion: SVM achieved a statistically significant better performance for this problem with an average accuracy of 0.9917 +/- 0.0024 and a F-Measure of 0.9925 +/- 0.0019, in comparison with ANN, which reached the values of 0.9847 +/- 0.0032 and 0.9852 +/- 0.0031 for Accuracy and F-Measure, respectively. A significant difference was observed between the performances obtained with SVM classifier using a different number of features from the original set available. Conclusion: The comparison between SVM and NN allowed reassert the higher performance of SVM. The results obtained in this study showed the potential of the proposed method to differentiate those three important signal outcomes (healthy, pathologic and noise) and to reduce bias associated with clinical diagnosis of cardiovascular disease using APW.

2018

AUTOMATIC METHODS FOR CAROTID CONTRAST-ENHANCED ULTRASOUND IMAGING QUANTIFICATION OF ADVENTITIAL VASA VASORUM

Authors
Pereira, T; Muguruza, J; Mária, V; Vilaprtnyo, E; Sorribas, A; Fernandez, E; Fernandez Armenteros, JM; Baena, JA; Rius, F; Betriu, A; Solsona, F; Alves, R;

Publication
ULTRASOUND IN MEDICINE AND BIOLOGY

Abstract

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