E. Charou

• PhD
• National Centre of Scientific Research "Demokritos"

Current Multi-View Stereo (MVS) algorithms are tools for high-quality 3D model reconstruction, strongly depending on image spatial resolution. In this context, the combination of image Super-Resolution (SR) with image-based 3D reconstruction is turning into an interesting research topic in photogrammetry, around which however only a few works have...

Geoscientists make huge efforts in order to develop techniques by the use of real-time predictive and analytical methods, in order to achieve better planning for constructions, Earth exploitation and prevention of natural hazard. A newly emerging approach for understanding remote sensing data, which is gradually becoming widely available, comes by...

Hyperspectral Imaging (HSI), or imaging spectroscopy, is an imaging method with numerous applications. Unlike conventional images, hyperspectral data contain information collected in narrow wavelength intervals at hundreds of bands across the electromagnetic spectrum. The resulting image has a high spatial and spectral resolution allowing for multi...

Climate change could exacerbate floods on agricultural plains by increasing the frequency of extreme and adverse meteorological events. Flood extent maps could be a valuable source of information for agricultural land decision makers, risk management and emergency planning. We propose a method that combines various types of data and processing tech...

This paper introduces the Class-wise Principal Component Analysis, a supervised feature extraction method for hyperspectral data. Hyperspectral Imaging (HSI) has appeared in various fields in recent years, including Remote Sensing. Realizing that information extraction tasks for hyperspectral images are burdened by data-specific issues, we identify...

Monitoring construction sites from space using high-resolution (HR) imagery enables remote tracking instead of physically traveling to a site. Thus, valuable resources are saved while recording of the construction site progression at anytime and anywhere in the world is feasible. In the present work Sentinel-2 (S2) images at 10 m (m) are spatially...

Procedural 3D Terrain generation has become a necessity in open world games, as it can provide unlimited content, through a functionally infinite number of different areas, for players to explore. In our approach, we use Generative Adversarial Networks (GAN) to yield realistic 3D environments based on the distribution of remotely sensed images of l...

In this paper we present our work on developing an automated system for land cover classification. This system takes a multiband satellite image of an area as input and outputs the land cover map of the area at the same resolution as the input. For this purpose convolutional machine learning models were trained in the task of predicting the land co...

The well-known technique outlined in the paper of Leon A. Gatys et al., A Neural Algorithm of Artistic Style, has become a trending topic both in academic literature and industrial applications. Neural Style Transfer (NST) constitutes an essential tool for a wide range of applications, such as artistic stylization of 2D images, user-assisted creati...

In this work, very deep super-resolution (VDSR) method is presented for improving the spatial resolution of remotely sensed (RS) images for scale factor 4. The VDSR net is re-trained with Sentinel-2 images and with drone aero orthophoto images, thus becomes RS-VDSR and Aero-VDSR, respectively. A novel loss function, the Var-norm estimator, is propo...

Deep learning techniques are applied so as to increase the spatial resolution of Sentinel2 satellite imagery, depicting the Amynteo lignite mine in Ptolemaida, Greece. Resolution enhancement by factors 2 and 4 as well as by factors 2 and 6 using Very-Deep SuperResolution (VDSR) and DSen2 networks, respectively, provides fairly well results on Amynt...

Generating Digital Elevation Models (DEM) from satellite imagery or other data sources constitutes an essential tool for a plethora of applications and disciplines, ranging from 3D flight planning and simulation, autonomous driving and satellite navigation, such as GPS, to modeling water flow, precision farming and forestry. The task of extracting...

Artificial Neural Networks (ANN) are mathematical computing paradigms imitating the operations of biological neural systems. Their nonlinear nature and ability to learn from the environment make them highly suited to solve real-world problems from those that are still under development. In the field of Physics there are many problems which cannot b...

Modern Information and Communication Technologies (ICT) have evolved into an ever developing digital ecosystem. In such a sophisticated system information is typically transmitted through interconnected software and hardware structures, better described as the well-known concept of Internet of Things (IoT). Embedded physical devices are producing d...

Due to the significant increase of tanker traffic from and to the Black Sea that pass through narrow straits formed by the 1600 Greek islands, the Aegean Sea is characterized by an extremely high marine environmental risk. Therefore it is vital to all socio-economic and environmental sectors to reduce the risk of a ship accident in that area. In th...

We live in an era where typical measures towards the mitigation of environmental degradation follow the identification and recording of natural parameters closely associated with it. In addition, current scientific knowledge on the one hand may be applied to minimize the environmental impact of anthropogenic activities, whereas informatics on the o...

The detailed three-dimensional modeling of buildings utilizing elevation data, such as those provided by light detection and ranging (LiDAR) airborne scanners, is increasingly demanded today. There are certain application requirements and available datasets to which any research effort has to be adapted. Our dataset includes aerial orthophotos, wit...

The amount of water flowing into the seas and oceans has slowly but steadily increased in recent years, signifying a possible speeding up of the water cycle due to climate change. The detection of the water outflows and the exploitation of them are very important to the rational water management. Remote sensing techniques has been proven a valuable...

Integrated techniques have been applied to support Geo-environmental studies of urban areas. The cities of Igoumenitsa and Volos, Greece have been selected as pilot project areas. Both optical and radar remote sensing systems have been used in order to study land cover changes, update geological maps and analyse areas of potential subsidence. Inter...

In a great variety of applications, such as real-time robot localization and visual navigation, architectural design, 3D city reconstruction, building recognition in urban environments is required. In this work a comparative study of visual feature extraction methods for building retrieval on urban databases is performed. To this end, a database of...

The Aegean Sea is characterized by an extremely high marine safety risk, mainly due to the significant increase of the traffic of tankers from and to the Black Sea that pass through narrow straits formed by the 1600 Greek islands. Reducing the risk of a ship accident is therefore vital to all socio-economic and environmental sectors. This paper pre...

Aegean Sea is an extremely sensitive marine area anticipating a catastrophic event to occur any time now, owing both to hazardous vessel crossing its waters and the significant rise of the intensive traffic. This paper aims to present a probabilistic Bayesian model predicting the probability of a collision, contact or grounding occurrence in the Ae...

Urban density is an important factor for several fields, e.g. urban design, planning and land management. Modern remote sensors deliver ample information for the estimation of specific urban land classification classes (2D indicators), and the height of urban land classification objects (3D indicators) within an Area of Interest (AOI). In this rese...

The Aegean Sea is characterized by an extremely high marine safety risk, mainly due to the significant increase of the traffic of tankers from and to the Black Sea that pass through narrow straits formed by the 1600 Greek islands. Reducing the risk of a ship accident is therefore vital to all socio-economic and environmental sectors. This paper pre...

Nowadays there is an increasing demand for detailed 3D modeling of buildings using elevation data such as those acquired from LiDAR airborne scanners. The various techniques that have been developed for this purpose typically perform segmentation into homogeneous regions followed by boundary extraction and are based on some combination of LiDAR dat...

The study presented here uses satellite information from Envisat Medium Resolution Imaging Spectrometer (MERIS), ground data and ancillary maps to access the use of MERIS satellite data in mapping burnt forest areas and monitoring their regeneration. A time series of MERIS images for 5 consecutive years 2007 to 2011 was processed. The MERIS based N...

Building detection has been a prominent area in the area of image classification. Most of the research effort is adapted to the specific application requirements and available datasets. In this paper we present a comparative analysis of different classification techniques for building block extraction. Our dataset includes aerial orthophotos (with...

Hyperspectral remote sensing images are consisted of several hundreds of contiguous spectral bands that can provide very rich information and has the potential to differentiate land cover classes with similar spectral characteristics. LIDAR data gives detailed height information and thus can be used complementary with Hyperspectral data. In this wo...

Vegetation is important because it provides the foundation of all terrestrial ecosystems. Indicators on vegetation can help track changes in the health and integrity of ecosystems. Also, indicators on vegetation responses to stresses like pollution and land uses can provide early warning of changes in ecosystems that are harder to measure. Various...

The study presented here uses satellite information from Envisat..Medium Resolution Imaging Spectrometer (MERIS), ground data and ancillary maps to access the use of MERIS satellite data in mapping burnt forest areas and monitoring their regeneration. A time series of MERIS images for 5 consecutive years 2007 to 2011 was processed. The MERIS based...

Monitoring of the lake ecosystems is of paramount importance for the overall development of a region. Remote sensing is a time- and cost-saving technique that enables the observation of the hydrological and limnological development of the lakes. The objective of this paper is to illustrate how multi-sensor and multi-platform remote sensing data and...

Sperchios river basin covers an area of 2116 km2, with an average altitude of approximately 810 m, while the river is recharged by many streams of permanent and periodic flow. The high gradients which are present within approximately 2/3 of the total length of the river course form a rather mountainous topography -streamy, with crucial flooding pea...

As concluded in the relevant UN Convention in 1994, desertification has affected large areas within the European Mediterranean coastal regions and is threatening even larger territories. Desertification as a means of land degradation can be resulted from a series of factors including climatic changes and anthropogenic activities; while appears more...

Research and monitoring is essential to assess baseline conditions in reservoirs and their watershed and provide necessary information to guide decision-makers. Erosion and degradation of mountainous areas can lead to gradual aggradation of reservoirs reducing their lifetime. Collected measurements and observations have to be communicated to the ma...

Mediterranean basin is considered as being highly susceptible to climate changes, especially as arid and semi-arid climate conditions as well as periodic draughts have caused a series of water-related rising problems. This issue becomes more pronounced in coastal river basins, which usually suffer major anthropogenic pressures such as growing water...

The environmental impacts following the closure of mining activities are investigated in the area of Aliveri, located in Evia Island, Central East Greece. The mining works resulted in new and very complex hydrogeological and geomechanical conditions, that caused cracks and huge gaps in the surface. The remnant mining voids were filled with water, t...

Traditional monitoring of lakes requires specialized personel and instrumentation for in situ and laboratory analysis. Continuous, up to date information is essential to all aspects of lake monitoring. The methodology presented here uses remote sensing technology, Geographical Information Systems (GIS) and hydrodynamic simulation for the study of l...

Environmental impact assessment is now an integral part of mining operations. Remote sensing data enables the identification, delineating, and monitoring of pollution sources and affected areas, including derelict land, and changes in surface land use and to water bodies. The aim of this work was to evaluate the use of multi-temporal Landsat-5 and...

In this paper a combination of traditional GIS along with multimedia, remotely sensed and GPS derived data is realised. Such a combination results in a multimedia GIS for accurate and valuable information concerning geotourism. A special feature of the multimedia GIS that was developed is that it contains information about the environmental challen...

Ecolourism as a growing source of revenue for the long-term management and care of vulnerableI natural destinations worldwide it's not just about driving more tourists to these locations. This research is ; focused on setting up a network of environmental routes through the utilization of new technologies (GIS and GPS). Corfu and Paxi islands were...

This paper presents the software life-cycle for the development of a knowledge-based GIS. The life-cycle framework used is called MBIUI and provides the experimental studies that are required for designing, implementing and testing a decision making theory in a graphical user interface. The decision making theory has been adapted in the user interf...

The research presented in this paper introduces a user context approach for the implementation of an adaptive Geographical Information System (GIS). The main focus of the paper is on presenting some implementation issues about the data used and their evaluation with respect to their suitability for the user interacting with the system. For the eval...

Image viewing and processing software in computed radiography manipulates image contrast in such a way that all relevant image features are rendered to an appropriate degree of visibility, and improves image quality using enhancement algorithms. The purpose of this study was to investigate procedures for the quality assessment of image processing s...

The Greek and EU legislatives' prescriptions in Environmental Impact Assessments Studies (EIA) impose habitat dynamic assessment and maps at large scale. Such studies need to exploit already accessible data as the ones from the Natura 2000 network. These data are insufficient to assess the habitat dynamics unless combining them with other character...

In this paper, some aspects of the usefulness of intelligent techniques in environmental data processing are discussed. The capabilities of neural networks in improving memory requirements for storage of environmental data and the increase in processing speed are analyzed. Finally, a software package for processing multi-source (geophysical, geoche...

The environmental monitoring of the quality of water is required by national laws and EU directives and in particular by the Water Framework Directive 2000/60. For a proper management, up to date information on the current status of the internal waters is needed. In this work multi sensor satellite data i.e. LANDSAT-ETM, ASTER and MERIS data are us...

The overall objectives of the GeoNickel project were to enhance geological and geophysical knowledge of nickel ore deposits and to develop novel, integrated exploration methods and tools for the European base-metals industry. The technologies developed are aimed at increasing the potential for success in exploration for sulphide and laterite nickel...

INTRODUCTION Lineaments are line features or patterns on earth's surface which reflect geological structure such as faults or fractures and should be discriminated from other line features (e.g. roads, airports) that are not due to geological structures. Detection and mapping of lineaments is an important operation in Environmental Geology for the...

A methodology based on self-organizing feature maps and indexing techniques for time and memory efficient neural network training and classification of large volumes of remotely sensed data is presented. Results on land-cover classification of multispectral satellite images using two popular neural models show orders of magnitude of speedup with re...

User’s manual

A time and memory efficient methodology for supervised and unsupervised land-cover classification of multispectral remote sensing (MRS) data based on artificial neural network (ANN) techniques is presented. The proposed methodology first performs a vector quantization (VQ) using the self-organizing maps (SOM) algorithm to compress the MRS data foll...

An automated lineament detection method based on a modified Hough transform is presented. The method first performs an efficient data clustering using Kohonen's self-organizing maps then binarizes the classification result and finally applies the modified Hough transform in order to identify lineaments. The capabilities of the method are described...

The proper management of water resources is an issue of worldwide concern nowadays. Lake Vegoritis is an important water impoundment located in the northern part of Greece, at an altitude of 510m and a northern latitude of 40 o 47΄, in an area with industrial, mining and agricultural activities which in various ways affect the qualitative and quant...

Various conventions have been established for the Protection and Use of Trans-boundary Watercourses and International Lakes which aim to strengthen national measures for the protection and ecologically sound management of trans-boundary surface waters and groundwater and establish concrete procedural obligations of cooperation between littoral stat...

post-processes the classification result with classical image processing techniques and finally applies the modified Hough transform in order to identify lineaments. The capabilities of the method are described using geophysical (airborne magnetic and electromagnetic) data from the Vammala area in Finland. The results of the automated analysis show...

In this work, a new methodology based on artificial neural networks (ANN) and indexing techniques is used with the aim to improve memory requirements for storing multi-source or multispectral remote sensing (MRS) data and at the same time increase classification speed. This methodology fea-tures: a) data quantization using a self-organizing map, b)...