2023 |
Zikas, Paul; Protopsaltis, Antonis; Lydatakis, Nick; Kentros, Mike; Geronikolakis, Stratos; Kateros, Steve; Kamarianakis, Manos; Evangelou, Giannis; Filippidis, Achilleas; Grigoriou, Eleni; Angelis, Dimitris; Tamiolakis, Michail; Dodis, Michael; Kokiadis, George; Petropoulos, John; Pateraki, Maria; Papagiannakis, George MAGES 4.0: Accelerating the World’s Transition to VR Training and Democratizing the Authoring of the Medical Metaverse Journal Article In: IEEE Computer Graphics and Applications, vol. 43, no. 2, pp. 43-56, 2023. Links | BibTeX | Tags: Behavioral sciences, Engines, Metaverse, Software, Task analysis, Training, visualization @article{Zikas2023, |
2021 |
Lourakis, Manolis; Pateraki, Maria Markerless Visual Tracking of a Container Crane Spreader Proceedings Article In: Proceedings of the IEEE/CVF International Conference on Computer Vision (ICCV) Workshops, pp. 2579-2586, 2021. Abstract | BibTeX | Tags: Cranes, Image segmentation, Motion segmentation, Solid modeling, Three-dimensional displays, Tracking, visualization @inproceedings{Lourakis_2021_ICCV, Crane systems play a crucial role in container transport logistics. This paper presents an approach for visually tracking the position and orientation in 3D space of a container crane spreader. An initial pose estimate is first employed to render a 3D triangle mesh model of the spreader as a wireframe with hidden lines removed. The initial pose is then refined so that the visible lines of the wireframe match the straight line segments detected in an input image. Line segment matching relies on fast, local one-dimensional searches along a segment’s normal direction. Matched line segments yield constraints on the spreader motion which are processed with robust parameter estimation techniques that safeguard against outliers stemming from mismatches. The tracker automatically determines the visibility of segments, without making limiting assumptions regarding the spreader’s 3D mesh model. It is also robust to parts of the tracked spreader being out of view, occluded, shadowed or simply undetected. Experimental results demonstrating the tracker’s performance are additionally included. |
Ioannidis, Charalabos; Soile, Sofia; Boutsi, Argyro-maria; Verykokou, Styliani; Bourexis, Fotios; Potsiou, Chryssy From 3D documentation to XR representation of Cultural Heritage buildings -The case of the Katholikon of St. Stephen, Meteora Proceedings Article In: FIG e-Working Week 2021, Smart Surveyors for Land and Water Management, 2021. Abstract | Links | BibTeX | Tags: 3D modelling, AR, Cultural heritage, Photogrammetry, visualization, VR @inproceedings{Ioannidis2021, Photogrammetric surveying and 3D modelling are of immense value for the diagnosis and conservation of historic and religious buildings. In case they are coupled with eXtended Reality (XR) technologies (i.e., Virtual, Augmented and Mixed Reality), different levels of interpretation, interaction and dissemination can be achieved. This paper presents a holistic approach to the multi-representation of the restoration phases of a Byzantine church. The aim is twofold; the introduction of a low-cost photogrammetric methodology for a detailed and accurate 3D geometric documentation of CH buildings, and the development of a web-based integrated 3D platform with XR functionalities. The proposed methodology is applied to the external and internal 3D reconstruction of the 16 th century old church (Katholikon) of St. Stephen's Monastery in Meteora, Greece, at two different periods: prior and after church maintenance work and restoration innervations. Close-range photogrammetry and computer vision are used for the collection of image data and the generation of dense point clouds, surface models and texture mapping. The final 3D models along with their supported metadata are integrated into an online XR viewer for a comparative temporal analysis through an immersive experience. The viewer has the following capabilities: (i) automated virtual tour on the 3D scene, (ii) points of interest, (iii) VR navigation as well as, (iv) marker-less AR based on hand pattern recognition. The 3D rendering and progressive loading, the interactive tools as well as the various visualization modes are built upon Three.js, Tween.js and AR.js libraries. The evaluation of the developed platform regarding performance and usability demonstrates the effectiveness of VR and AR in remote access, monitoring and preservation of tangible Cultural Heritage. |
2020 |
Ioannidis, Charalabos; Verykokou, Styliani; Soile, Sofia; Boutsi, Argyro-Maria A MULTI-PURPOSE CULTURAL HERITAGE DATA PLATFORM FOR 4D VISUALIZATION AND INTERACTIVE INFORMATION SERVICES Journal Article In: ISPRS - Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci., vol. XLIII-B4-2, no. B4, pp. 583–590, 2020, ISSN: 2194-9034. Abstract | Links | BibTeX | Tags: 4D modelling, Cultural heritage, Documentation, geospatial data, visualization @article{Ioannidis2020b, Abstract. The already arduous task of collecting, processing and managing heterogeneous cultural heritage data is getting more intense in terms of indexing, interaction and dissemination. This paper presents the creation of a 4D web-based platform as a centralized data hub, moving beyond advanced photogrammetric techniques for 3D capture and multi-dimensional documentation. Precise metric data, generated by a combination of image-based, range and surveying techniques, are spatially, logically and temporally correlated with cultural and historical resources, in order to form a critical knowledge base for multiple purposes and user types. Unlike conventional information systems, the presented platform, which adopts a relational database model, has the following front-end functionalities: (i) visualization of high-resolution 3D models based on distance dependent Level of Detail (LoD) techniques; (ii) web Augmented Reality; and (iii) interactive access and retrieval services. Information deduced from the developed services is tailored to different target audiences: scientific community, private sector, public sector and general public. The case study site is the UNESCO world heritage site of Meteora, Greece, and particularly, two inaccessible huge rocks, the rock of St. Modestos, known as Modi, and the Alyssos rock. |
2023 |
MAGES 4.0: Accelerating the World’s Transition to VR Training and Democratizing the Authoring of the Medical Metaverse Journal Article In: IEEE Computer Graphics and Applications, vol. 43, no. 2, pp. 43-56, 2023. |
2021 |
Markerless Visual Tracking of a Container Crane Spreader Proceedings Article In: Proceedings of the IEEE/CVF International Conference on Computer Vision (ICCV) Workshops, pp. 2579-2586, 2021. |
From 3D documentation to XR representation of Cultural Heritage buildings -The case of the Katholikon of St. Stephen, Meteora Proceedings Article In: FIG e-Working Week 2021, Smart Surveyors for Land and Water Management, 2021. |
2020 |
A MULTI-PURPOSE CULTURAL HERITAGE DATA PLATFORM FOR 4D VISUALIZATION AND INTERACTIVE INFORMATION SERVICES Journal Article In: ISPRS - Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci., vol. XLIII-B4-2, no. B4, pp. 583–590, 2020, ISSN: 2194-9034. |