Konstantinos Makantasis

Dr. Konstantinos Makantasis

Institute of Digital Games, University of Malta, 20 Triq L-Esperanto, MSD2080 Msida, Malta
orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

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

Representative Publications

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1 July 2015
Verified
Conference Paper
Closed access
Konstantinos MakantasisKonstantinos Makantasis
Konstantinos Makantasis
Konstantinos KarantzalosKonstantinos Karantzalos
Konstantinos Karantzalos
ADAnastasios Doulamis
Anastasios Doulamis
NDNikolaos Doulamis
Nikolaos Doulamis
Spectral observations along the spectrum in many narrow spectral bands through hyperspectral imaging provides valuable information towards material and object recognition, which can be consider as a classification task. Most of the existing studies and research efforts are following the conventional pattern recognition paradigm, which is based on the construction of complex handcrafted features. However, it is rarely known which features are important for the problem at hand. In contrast to these approaches, we propose a deep learning based classification method that hierarchically constructs high-level features in an automated way. Our method exploits a Convolutional Neural Network to encode pixels' spectral and spatial information and a Multi-Layer Perceptron to conduct the classification task. Experimental results and quantitative validation on widely used datasets showcasing the potential of the developed approach for accurate hyperspectral data classification.

1 September 2015
Verified
Conference Paper
Closed access
Konstantinos MakantasisKonstantinos Makantasis
Konstantinos Makantasis
Eftychios ProtopapadakisEftychios Protopapadakis
Eftychios Protopapadakis
ADAnastasios Doulamis
Anastasios Doulamis
NDNikolaos Doulamis
Nikolaos Doulamis
CLConstantinos Loupos
Constantinos Loupos
The inspection, assessment, maintenance and safe operation of the existing civil infrastructure consists one of the major challenges facing engineers today. Such work requires either manual approaches, which are slow and yield subjective results, or automated approaches, which depend upon complex handcrafted features. Yet, for the latter case, it is rarely known in advance which features are important for the problem at hand. In this paper, we propose a fully automated tunnel assessment approach; using the raw input from a single monocular camera we hierarchically construct complex features, exploiting the advantages of deep learning architectures. Obtained features are used to train an appropriate defect detector. In particular, we exploit a Convolutional Neural Network to construct high-level features and as a detector we choose to use a Multi-Layer Perceptron due to its global function approximation properties. Such an approach achieves very fast predictions due to the feedforward nature of Convolutional Neural Networks and Multi-Layer Perceptrons.

14 August 2014 in Multimedia Tools and Applications
Verified
Journal Article
Closed access
PDF file
Konstantinos MakantasisKonstantinos Makantasis
Konstantinos Makantasis
ADAnastasios Doulamis
Anastasios Doulamis
NDNikolaos Doulamis
Nikolaos Doulamis
MIMarinos Ioannides
Marinos Ioannides

7 November 2019 in IET Intelligent Transport Systems
Verified
Journal Article
Open access
PDF file
Konstantinos MakantasisKonstantinos Makantasis
Konstantinos Makantasis
MKMaria Kontorinaki
Maria Kontorinaki
INIoannis Nikolos
Ioannis Nikolos
In this work, the problem of path planning for an autonomous vehicle that moves on a freeway is considered. The most common approaches that are used to address this problem are based on optimal control methods, which make assumptions about the model of the environment and the system dynamics. On the contrary, this work proposes the development of a driving policy based on reinforcement learning. In this way, the proposed driving policy makes minimal or no assumptions about the environment, since a priori knowledge about the system dynamics is not required. Driving scenarios where the road is occupied both by autonomous and manual driving vehicles are considered. To the best of the authors’ knowledge, this is one of the first approaches that propose a reinforcement learning driving policy for mixed driving environments. The derived reinforcement learning policy, firstly, is compared against an optimal policy derived via dynamic programming, and, secondly, its efficiency is evaluated under realistic scenarios generated by the established SUMO microscopic traffic flow simulator. Finally, some initial results regarding the effect of autonomous vehicles’ behaviour on the overall traffic flow are presented.

22 February 2021 in IEEE Transactions on Affective Computing
Verified
Journal Article
Closed access
Konstantinos MakantasisKonstantinos Makantasis
Konstantinos Makantasis
ALAntonios Liapis
Antonios Liapis
GYGeorgios N. Yannakakis
Georgios N. Yannakakis
What if emotion could be captured in a general and subject-agnostic fashion Is it possible, for instance, to design general-purpose representations that detect affect solely from the pixels and audio of a human-computer interaction video In this paper we address the above questions by evaluating the capacity of deep learned representations to predict affect by relying only on audiovisual information of videos. We assume that the pixels and audio of an interactive session embed the necessary information required to detect affect. We test our hypothesis in the domain of digital games and evaluate the degree to which deep classifiers and deep preference learning algorithms can learn to predict the arousal of players based only on the video footage of their gameplay. Our results from four dissimilar games suggest that general-purpose representations can be built across games as the arousal models obtain average accuracies as high as 85% using the challenging leave-one-video-out cross-validation scheme. The dissimilar audiovisual characteristics of the tested games showcase the strengths and limitations of the proposed method.

31 July 2013 in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Verified
Journal Article
Open access
PDF file
Marinos IoannidesMarinos Ioannides
Marinos Ioannides
AHA. Hadjiprocopi
A. Hadjiprocopi
NDN. Doulamis
N. Doulamis
ADA. Doulamis
A. Doulamis
Eftychios ProtopapadakisEftychios Protopapadakis
Eftychios Protopapadakis
Hans Dieter FritschHans Dieter Fritsch
Hans Dieter Fritsch
The advent of technology in digital cameras and their incorporation into virtually any smart mobile device has led to an explosion of the number of photographs taken every day. Today, the number of images stored online and available freely has reached unprecedented levels. It is estimated that in 2011, there were over 100 billion photographs stored in just one of the major social media sites. This number is growing exponentially. Moreover, advances in the fields of Photogrammetry and Computer Vision have led to significant breakthroughs such as the Structure from Motion algorithm which creates 3D models of objects using their twodimensional photographs. The existence of powerful and affordable computational machinery not only the reconstruction of complex structures but also entire cities. This paper illustrates an overview of our methodology for producing 3D models of Cultural Heritage structures such as monuments and artefacts from 2D data (pictures, video), available on Internet repositories, social media, Google Maps, Bing, etc. We also present new approaches to semantic enrichment of the end results and their subsequent export to Europeana, the European digital library, for integrated, interactive 3D visualisation within regular web browsers using WebGl and X3D. Our main goal is to enable historians, architects, archaeologists, urban planners and affiliated professionals to reconstruct views of historical structures from millions of images floating around the web and interact with them.