Vasco Lopes

Mr. Vasco Lopes

Universidade da Beira Interior
+1
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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6 July 2020 in IEEE Journal of Selected Topics in Signal Processing
Verified
Journal Article
Closed access
João C. NevesJoão C. Neves
João C. Neves
RTRuben Tolosana
Ruben Tolosana
RVRuben Vera-Rodriguez
Ruben Vera-Rodriguez
Vasco LopesVasco Lopes
Vasco Lopes
Hugo ProençaHugo Proença
Hugo Proença
Julian FierrezJulian Fierrez
Julian Fierrez
The availability of large-scale facial databases, together with the remarkable progresses of deep learning technologies, in particular Generative Adversarial Networks (GANs), have led to the generation of extremely realistic fake facial content, raising obvious concerns about the potential for misuse. Such concerns have fostered the research on manipulation detection methods that, contrary to humans, have already achieved astonishing results in various scenarios. In this study, we focus on the synthesis of entire facial images, which is a specific type of facial manipulation. The main contributions of this study are four-fold: i) a novel strategy to remove GAN fingerprints from synthetic fake images based on autoencoders is described, in order to spoof facial manipulation detection systems while keeping the visual quality of the resulting images; ii) an in-depth analysis of the recent literature in facial manipulation detection; iii) a complete experimental assessment of this type of facial manipulation, considering the state-of-the-art fake detection systems (based on holistic deep networks, steganalysis, and local artifacts), remarking how challenging is this task in unconstrained scenarios; and finally iv) we announce a novel public database, named iFakeFaceDB, yielding from the application of our proposed GAN-fingerprint Removal approach (GANprintR) to already very realistic synthetic fake images. The results obtained in our empirical evaluation show that additional efforts are required to develop robust facial manipulation detection systems against unseen conditions and spoof techniques, such as the one proposed in this study.

7 September 2021
Verified
Book Chapter
Closed access
PDF file
Vasco LopesVasco Lopes
Vasco Lopes
SASaeid Alirezazadeh
Saeid Alirezazadeh
LALuís A. Alexandre
Luís A. Alexandre

9 April 2019 in Ledger
Verified
Journal Article
Open access
PDF file
Vasco LopesVasco Lopes
Vasco Lopes
LALuís A Alexandre
Luís A Alexandre
Blockchain technology is growing everyday at a fast-passed rhythm and it is possible to integrate it with many systems, namely Robotics with AI services. However, this is still a recent field and there is not yet a clear understanding of what it could potentially become. In this paper, we conduct an overview of many different methods and platforms that try to leverage the power of blockchains into robotic systems, to improve AI services, or to solve problems that are present in the major blockchains, which can lead to the ability of creating robotic systems with increased capabilities and security. We present an overview, discuss the methods, and conclude the paper with our view on the future of the integration of these technologies.

9 September 2020 in Mathematics
Verified
Journal Article
Open access
PDF file
Fernando M. L. MartinsFernando M. L. Martins
Fernando M. L. Martins
Ricardo GomesRicardo Gomes
Ricardo Gomes
Vasco LopesVasco Lopes
Vasco Lopes
FSFrutuoso G. M. Silva
Frutuoso G. M. Silva
Rui Manuel Sousa MendesRui Manuel Sousa Mendes
Rui Manuel Sousa Mendes
Pattern analysis is a well-established topic in team sports performance analysis, and is usually centered on the analysis of passing sequences. Taking a Bayesian approach to the study of these interactions, this work presents novel entropy mathematical models for Markov chain-based pattern analysis in team sports networks, with Relative Transition Entropy and Network Transition Entropy applied to both passing and reception patterns. To demonstrate their applicability, these mathematical models were used in a case study in football—the 2016/2017 Champions League Final, where both teams were analyzed. The results show that the winning team, Real Madrid, presented greater values for both individual and team transition entropies, which indicate that greater levels of unpredictability may bring teams closer to victory. In conclusion, these metrics may provide information to game analysts, allowing them to provide coaches with accurate and timely information about the key players of the game.

29 April 2021 in SN Applied Sciences
Verified
Journal Article
Open access
PDF file
Gaspar RamôaGaspar Ramôa
Gaspar Ramôa
Vasco LopesVasco Lopes
Vasco Lopes
LALuís A. Alexandre
Luís A. Alexandre
Sandra MogoSandra Mogo
Sandra Mogo
In this paper, we propose three methods for door state classification with the goal to improve robot navigation in indoor spaces. These methods were also developed to be used in other areas and applications since they are not limited to door detection as other related works are. Our methods work offline, in low-powered computers as the Jetson Nano, in real-time with the ability to differentiate between open, closed and semi-open doors. We use the 3D object classification, PointNet, real-time semantic segmentation algorithms such as, FastFCN, FC-HarDNet, SegNet and BiSeNet, the object detection algorithm, DetectNet and 2D object classification networks, AlexNet and GoogleNet. We built a 3D and RGB door dataset with images from several indoor environments using a 3D Realsense camera D435. This dataset is freely available online. All methods are analysed taking into account their accuracy and the speed of the algorithm in a low powered computer. We conclude that it is possible to have a door classification algorithm running in real-time on a low-power device.

16 March 2024 in Neurocomputing
Verified
Journal Article
Open access
Vasco LopesVasco Lopes
Vasco Lopes
MSMiguel Santos
Miguel Santos
BDBruno Degardin
Bruno Degardin
LALuís A. Alexandre
Luís A. Alexandre