Xenophon Zabulis

• PhD
• Researcher at Foundation for Research and Technology Hellas

This paper presents an augmented reality environment for students' improved learning, which is based on unobtrusive monitoring of the natural reading and writing process. This environment, named SESIL, is able to perform recognition of book pages and of specific elements of interest within a page, as well as to perceive interaction with actual book...

We propose a method for human head pose estimation based on images acquired by a depth camera. During an initialization phase, a reference depth image of a human subject is obtained. At run time, the method searches the 6-dimensional pose space to find a pose from which the head appears identical to the reference view. This search is formulated as a...

This publication highlights the strategic combination of the preservation of heritage and innovation for supporting the sustainability of traditional crafts in Europe. Demonstrating both challenges and opportunities faced by artisans, there is a need to balance cultural authenticity and the pressures of current markets and environmental imperatives...

Digital tools exhibit the potential to support the sustainability of traditional crafts through training and presentation applications. This work presents an integrated approach, combining state-of-the-art simulation and visualisation techniques to model mechanical actions characteristic of traditional crafts. This integration promotes a deeper und...

The problem of modelling and simulating traditional crafting actions is addressed, motivated by the goals of craft understanding, documentation, and training. First, the physical entities involved in crafting actions are identified, physically, and semantically characterised, including causing entities, conditions, properties, and objects, as well...

We address the problem of systematizing the authoring of digital dictionaries for craft education from ethnographic studies and recordings. First, we present guidelines for the collection of ethnographic data using digital audio and video and identify terms that are central in the description of crafting actions, products, tools, and materials. Sec...

In this paper, we present a comprehensive methodology to support the multifaceted process involved in the digitization, curation, and virtual exhibition of cultural heritage artifacts. The proposed methodology is applied in the context of a unique collection of contemporary dresses inspired by antiquity. Leveraging advanced 3D technologies, includi...

The evolution of digital technologies has resulted in the emergence of diverse interaction technologies. In this paper, we conducted a review of seven domains under a human-centric approach user interface design, human-centered web-based information systems, semantic knowledge representation, X-reality applications, human motion and 3D digitization...

Craft education and training are important for preserving cultural heritage and fostering artisanal skills. However, the pedagogical challenges in this domain are numerous. This research paper presents a comprehensive framework for applying Cognitive Load Theory to enhance craft education and training via eLearning platforms. In this study, practic...

The practical, rapid, and accurate optical 3D reconstruction of transparent objects with contemporary non-contact optical techniques, has been an open challenge in the field of optical metrology. The combination of refraction, reflection, and transmission in transparent objects makes it very hard to use common off-the-shelf 3D reconstruction soluti...

This entry discusses the challenge of safeguarding crafts in Europe. Safeguarding is defined herein as the systematic process of understanding, representing, preserving, and valorizing crafts following the recommendations of UNESCO and the UN-World Tourism Organization. The abovementioned challenges are discussed through a multidisciplinary prism s...

A close-range photogrammetric approach and its implementation using a CNC device and a macro camera are proposed. A tailored image acquisition approach is proposed that is implemented using this device. To increase reconstruction robustness and accuracy, the key point features detected in the acquired images are tracked across multiple views from m...

A roadmap is proposed that defines a systematic approach for craft preservation and its evaluation. The proposed roadmap aims to deepen craft understanding so that blueprints of appropriate tools that support craft documentation, education, and training can be designed while achieving preservation through the stimulation and diversification of prac...

A roadmap is proposed that defines a systematic approach for craft preservation and its evaluation. The proposed roadmap aims at deepening craft understanding, so blueprints of appropriate tools that support craft documentation, education, and training can be designed while achieving preservation through the stimulation and diversification of pract...

Objective Central blood pressure (cBP) has been more closely associated with target-organ damage compared with brachial BP, although a bidirectional interplay between central and peripheral arteries exists. Brachial short term BP variability (BPV) has been increasingly related to impaired macro- and microvascular function. However, scarce data exis...

Advances in digitization technologies have made possible the digitization of entire archaeological sites through a combination of technologies, including aerial photogrammetry, terrestrial photogrammetry, and terrestrial laser scanning. At the same time, the evolution of computer algorithms for data processing and the increased processing power mad...

Modern digitization technologies have created an increasing number of possibilities for capturing the physical dimensions and appearance of archaeological artifacts and sites in 3D. The usage of such data is usually targeted to the research, study, and documentation of our cultural heritage. At the same time, the increasing quality of the produced...

The population ageing problem and the need for finding feasible solutions and tools to support elderly people in self-managing their well-being and maintaining their independence and Quality of Life (QoL) have drawn the attention of the research community of multiple disciplines. In particular, mHealth taking advantage of advances in wearables that...

Objectives: Increased blood pressure variability (BPV) has been associated with an increased risk of subclinical organ damage and cardiovascular events, independently of elevated average BP values. We aimed to investigate the association of BPV indices with micro- and macrovascular parameters, some of them not previously studied. Methods: We eva...

Food preparation is one of the essential tasks in daily life and involves a large number of physical interactions between hands, utensils, ingredients, etc. The fundamental unit in the food preparation activity is the concept of a recipe. The recipe describes the cooking process—the way to make a dish in a sequential order of cooking steps. Frequen...

An approach to the representation and documentation of craft processes is proposed. The proposed approach is a method for the systematic identification and digital representation of pertinent data, information, and knowledge. The outcome representation is compatible with contemporary digitisation practices and digital preservation standards. The im...

Virtual humans (VHs) are gaining increasing attention in various fields, including games and cultural heritage and technological contexts including virtual reality and augmented reality. Recently, since VHs can simulate human-like behavior, VHs have been proposed as virtual assistants (VAs) for all sorts of education and training applications, incl...

Temporary exhibitions have not only been the oldest, but also the most successful model of art mediation (e.g., the Venice Biennale). In this research work, we are interested in the subject of preserving periodic exhibitions in the form of an interactive virtual memory to be revisited in the future. Although popular forms for doing so include photo...

This work compares four different image processing algorithms for the analysis of image data obtained during the Multiscale Boiling Experiment of ESA, executed on-board the International Space Station. Two separate experimental campaigns have been performed in 2019 and 2020, aiming to investigate boiling phenomena in microgravity, with and without...

Intangible heritage is often linked to human actions and performances. The use of digital humans (DHs) for its digital representation and therefore its preservation, allows reframing the way to transmit and deal with content that is difficult to visualize. To that end, the digital human becomes an important element establishing the connection betwe...

A web-based authoring platform for the representation of traditional crafts is proposed. This platform is rooted in a systematic method for craft representation, the adoption, knowledge, and representation standards of the cultural heritage (CH) domain, and the integration of outcomes from advanced digitization techniques. In this paper, we present...

Caves can be considered as features of the landscape that have been formatted through a long period and are signs of the past climatological conditions, of prehistoric animal and human inhabitation, and provide habitat for species. In the near past, caves have also gained tourism interest since they offer unique sightseeing experiences. The sustain...

Visualizing human motion is a topic that has gained increasing attention in the domain of cultural heritage, due to the need for capturing intangible dimensions, existing for example in theatrical performances, dances, and crafts. In this respect, virtual humans are typically employed to re-enact human motion, executing movements reproduced through...

A protocol for the representation of traditional crafts and the tools to implement this are proposed. The proposed protocol is a method for the systematic collection and organization of digital assets and knowledge, their representation into a formal model, and their utilization for research, education, and preservation. A set of digital tools acco...

This publication lays the foundation for the description of the Multiscale Boiling Experiment, which was conducted within two measurement campaigns on the International Space Station between 2019 and 2021. The experiment addresses fundamental questions about two-phase heat transfer during boiling processes. For this purpose, single or few subsequen...

In this paper, a representation based on digital assets and semantic annotations is established for Traditional Craft instances, in a way that captures their socio-historic context and preserves both their tangible and intangible Cultural Heritage dimensions. These meaningful and documented experiential presentations are delivered to the target aud...

In this article, the Mingei Online Platform is presented as an authoring platform for the representation of social and historic context encompassing a focal topic of interest. The proposed representation is employed in the contextualised presentation of a given topic, through documented narratives that support its presentation to diverse audiences....

This work regards the representation of handicrafts for craft training and demonstration in the environment of an ethnographic heritage museum. The craft of mastic cultivation is chosen as a use case. This paper presents the process of representation and presentation of this craft, following an articulated pipeline approach for data collection, ann...

An approach to the representation and documentation of craft processes is proposed. The proposed approach is a method for the systematic identification and digital representation of pertinent data, information, and knowledge. The outcome representation is compatible with contemporary digitisation practices and digital preservation standards. The im...

An approach to the representation and presentation of spatial and geographical context of cultural heritage sites is proposed. The goal is to combine semantic representations of social and historical context with 3D representations of cultural heritage sites acquired through 3D reconstruction and 3D modeling technologies, to support their interpret...

Traditional crafts exhibit tangible and intangible dimensions. Intangible dimensions include the practitioner’s gestural know-how in craft practice and have received smaller attention than tangible dimensions in digitization projects. This work presents the process of representation and presentation of the glasswork and is exemplified in the re-cre...

The accessibility of Cultural Heritage content for the diverse user population visiting Cultural Heritage Institutions and accessing content online has not been thoroughly discussed. Considering the penetration of new digital media in such physical and virtual spaces, lack of accessibility may result in the exclusion of a large user population. To...

Traditional crafts involve craft artefacts, materials and tools while encompassing craftsmanship as a form of intangible cultural heritage (ICH). In modern societies, the production of traditional crafts (TCs) has decreased due to the lack of interest and the reduction in the number of practitioners. In this context, we explore modern digital techn...

Virtual Humans are becoming a commodity in computing technology and lately have been utilized in the context of interactive presentations in Virtual Cultural Heritage environments and exhibitions. To this end, this research work underlines the importance of aligning and fine-tuning Virtual Humans’ appearance to their roles and highlights the import...

A valuable aspect during crime scene investigation is the digital documentation of the scene. Traditional means of documentation include photography and in situ measurements from experts for further analysis. Although 3D reconstruction of pertinent scenes has already been explored as a complementary tool in investigation pipelines, such technology...

The design and implementation of a contactless scanner and its software are proposed. The scanner regards the photographic digitization of planar and approximately planar surfaces and is proposed as a cost-efficient alternative to off-the-shelf solutions. The result is 19.8 Kppi micrometer scans, in the service of several applications. Accurate sur...

Visualization techniques for the usage of tools, handicrafts, and assembly operations are employed for demonstrating processes (e.g., assembly instructions). Until today, most commonly used techniques include written information, sketches in manuals, video instructions, etc. The evolution of technology nowadays has generated mature methods for tran...

This paper presents a knowledge representation framework and provides tools to allow the representation and presentation of the tangible and intangible dimensions of culinary tradition as cultural heritage including the socio-historic context of its evolution. The representation framework adheres to and extends the knowledge representation standard...

Advances in Cultural Heritage (CH) representation and presentation technologies are explored concerning new potentials brought by the gaming industry. These include the use of digitisation technologies for the creation of realistic digital assets, educational gaming concepts, and immersive technologies. In this context, it is shown how the creative...

Improving the well-being and quality of life of the elderly population is closely related to assisting them to effectively manage age-related conditions such as chronic illnesses and anxiety, and to maintain their independence and self-sufficiency as much as possible. This paper presents the design, architecture and implementation structure of an a...

Existing, fully supervised methods for person re-identification (ReID) require annotated data acquired in the target domain in which the method is expected to operate. This includes the IDs as well as images of persons in that domain. This is an obstacle in the deployment of ReID methods in novel settings. For solving this problem, semi-supervised...

Background and Objective: The study of small vessels allows for the analysis and diagnosis of diseases with strong vasculopathy. This type of vessels can be observed non-invasively in the retina via fundoscopy. The analysis of these vessels can be facilitated by applications built upon Retinal Image Registration (RIR), such as mosaicing, Super Reso...

A wide spectrum of digital data are becoming available to researchers and industries interested in the recording, documentation, recognition, and reproduction of human activities. In this work, we propose an approach for understanding and articulating human motion recordings into multimodal datasets and VR demonstrations of actions and activities r...

The visualization of 3D human motion on a 2D canvas or display is employed by a wide spectrum of disciplines to abstract and provide insight on the motion of human subjects that is depicted by the 2D medium. Painters, illustrators and directors use motion lines, contrast, superimposition as well as juxtaposition of visual frames for a better convey...

Heritage Crafts (HCs) involve craft artefacts, materials, and tools and encompass craftsmanship as a form of Intangible Cultural Heritage. Intangible HC dimensions include dexterity, know-how, and skilled use of tools, as well as identity and traditions of the communities in which craftsmanship is, or was, practiced. HCs are part of history and hav...

The Mingei Crafts Ontology

formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> $Objective:$ In-vivo assessment of small vessels can promote accurate diagnosis and monitoring of diseases related to vasculopathy, such as hypertension and diabetes. The eye provides a unique, open, and accessible window for directly imaging small v...

Despite the cultural, societal, economic and traditional significance and value of Heritage Crafts and Intangible Cultural Heritage, efforts towards their digital representation and presentation, and subsequently their preservation, are scattered. To that end, this paper proposes an approach for their visualization in Virtual Environments, within w...

This work regards the digital representation of tangible and intangible dimensions of heritage crafts, towards craft preservation. Based on state-of-the-art digital documentation, knowledge representation and narrative creation approach are presented. Craft presentation methods that use the represented content to provide accurate, intuitive, engagi...

Heritage Crafts (HCs) involve tangible craft artefacts, materials, and tools and encompass traditional craftsmanship as a form of Intangible Cultural Heritage. Intangible HC dimensions include dexterity, know-how, and skilled use of tools, as well as identity and traditions of the communities in which craftsmanship is, or was, practiced. Despite th...

Heritage Crafts (HCs) involve tangible craft artefacts, materials, and tools and encompass traditional craftsmanship as a form of Intangible Cultural Heritage. Intangible HC dimensions include dexterity, know-how, and skilled use of tools, as well as identity and traditions of the communities in which craftsmanship is, or was, practised. Despite th...

Preprocessing and enhancement is a prerequisite for a wide range of retinal image analysis methods. The goals of such tasks are to improve images and facilitate their subsequent analysis. Registration of retinal images enables the generation of images of higher definition retinal mosaics and facilitates the comparison of images from different exami...

Increased mobile autonomy is a vital requisite for future planetary exploration rovers. Stereo vision is a key enabling technology in this regard, as it can passively reconstruct in three dimensions the surroundings of a rover and facilitate the selection of science targets and the planning of safe routes. Nonetheless, accurate dense stereo algorit...

Future autonomous spacecraft rendezvous with uncooperative or unprepared objects will be enabled by vision-based navigation, which imposes great computational challenges. Targeting short duration missions in low Earth orbit, this paper develops high-performance avionics supporting custom computer vision algorithms of increased complexity for satell...

Future autonomous spacecraft rendezvous with uncooperative or unprepared objects will be enabled by visionbased navigation, which imposes great computational challenges. Targeting short duration missions in low Earth orbit, this paper develops high-performance avionics supporting custom computer vision algorithms of increased complexity for satelli...

Evidence suggests that increased salt consumption induces blood pressure- (BP) mediated organ damage, yet it remains unclear whether it reflects a generalized micro- and macrovascular malfunction independent of BP. We studied 197 newly diagnosed and never-treated individuals with hypertension, intermediate hypertensive phenotypes, and normal BP, cl...

Objective Increased urinary albumin excretion (UAE) is a marker of generalized vascular damage in high cardiovascular risk patients. However, it remains unknown whether it corresponds to a state of diffuse vasculopathy in high‐risk patients with rheumatoid arthritis (RA). Methods UAE was estimated in 24‐hour urine samples in RA and non‐RA individu...

We propose a benchmark for 6D pose estimation of a rigid object from a single RGB-D input image. The training data consists of a texture-mapped 3D object model or images of the object in known 6D poses. The benchmark comprises of: (i) eight datasets in a unified format that cover different practical scenarios, including two new datasets focusing on...

We propose a benchmark for 6D pose estimation of a rigid object from a single RGB-D input image. The training data consists of a texture-mapped 3D object model or images of the object in known 6D poses. The benchmark comprises of: i) eight datasets in a unified format that cover different practical scenarios, including two new datasets focusing on...

The case of mixed-reality projector-camera systems is considered and, in particular, those which employ hand-held boards as interactive displays. This work focuses upon the accurate, robust, and timely detection and pose estimation of such boards, to achieve high-quality augmentation and interaction. The proposed approach operates a camera in the n...

This paper presents an Ambient Intelligence infrastructure that fuses state-of-the-art technologies and related applications with digital cultural resources to deliver interactive and immersive user encounters through on-site Virtual Exhibitions (VEs) which respond to the demands of ‘new museology’. The practical exploitation of the concept is pres...

The Tourism Office of the city of Heraklion is a truly original facility that provides visitors with novel ways to access information through the use of modern technologies and innovative interactive systems developed by ICS-FORTH. This paper presents the innovative technologies employed at the tourist information office in order to enhance the inf...

This paper presents COIN-O-RAMA, an interactive exhibit designed for exploring and further engaging with coins in physical exhibitions. The key motivation was to create an appealing and user friendly system, augmenting and complementing the overall experience of visiting the exhibition, also offering the means for creating a personalized digital so...

Autonomous navigation of planetary exploration rovers has become a key element to attain mission success, as it can significantly improve the length of daily traverses, particularly when driving in unknown areas away from the lander. Future missions, such as the Mars Sample Return or the Lunar Polar Sample Return, already demand longer and faster t...

A new software tool is developed for droplet image analysis for the study of wetting of solid substrates. The tool extracts information exclusively from images and does not require the use of any properties of the system. Moreover, its applicability covers both axisymmetric and non-axisymmetric droplets. The developed software processes independent...

Objective Capillary rarefaction is observed in various cardiovascular diseases, yet it remains understudied in RA, a chronic inflammatory disease accompanied by excess cardiovascular risk. We quantified capillary density in RA patients and explored potential associations with macrocirculatory disorders, inflammation and cardiovascular risk. Method...

Despite the extensive study of wetting in literature, there are still many unresolved issues regarding forced wetting. One of them refers to the effect of the initial droplet shape on the force required for spreading and sliding along a solid surface; an effect that has not ever been explicitly reported. Previous experimental works, in general, ass...

Vision-based navigation has become increasingly important in a variety of space appli- cations for enhancing autonomy and dependability. Future missions such as Active Debris Removal will rely on novel high-performance avionics to support advanced image process- ing algorithms with large workloads. However, constraints relating to the use of electr...

Estimating the pose of objects from depth data is a problem of considerable practical importance for many vision applications. This paper presents an approach for accurate and efficient 3D pose estimation from noisy 2.5D depth images obtained from a consumer depth sensor. Initialized with a coarsely accurate pose, the proposed approach applies a hy...

Objective: Quantification of retinal vessel morphology has emerged as a marker of cardiovascular health. We examined retinal microvascular diameters in RA, particularly in regard with systemic inflammation, subclinical atherosclerosis and cardiovascular risk. Methods: Retinal images from RA patients and controls were processed using computerized...