2025

• V. E. Kotsis-Panakakis, I. Evangelou, F. Bistas, A. Gkaravelis, N. Vitsas, A. A. Vasilakis, G. Papaioannou, HOPE: Holographic Optimized Processing Engine, EuroXR 2025, poster session, 2025.
• G. Papaioannou, Approximate Dynamic Global Illumination for VR, Virtual Reality 29, 54, 2025.
• G. Papaioannou, E. Pertesi, D. Michailidis, A. A. Vasilakis, Corrective Hybrid 3D Digitization, Proc. 52nd Int. Conf. Computer Applications and Quantitative Methods in Archaeology (CAA), 2025.
• S. Costopoulos, G. Papaioannou, The Impact of Normal Mapping on the Geometric Simplification of Archaeological 3D Data, Proc. 52nd Int. Conf. Computer Applications and Quantitative Methods in Archaeology (CAA), 2025.
• M. Grigoriadi, G. Papaioannou, Spatiotemporal Reconstruction of Pot Burial Excavations, Proc. 52nd Int. Conf. Computer Applications and Quantitative Methods in Archaeology (CAA), 2025.

2024

• I. Evangelou, N. Vitsas, G. Papaioannou, A. Gkaravelis, A Generative Approach to Light Placement for Street Lighting, Proc. Eurographics 2024 (short paper track), 2024.

2023

• N. Vitsas, I. Evangelou, G. Papaioannou, A. Gkaravelis, Opening Design using Bayesian Optimization, Proc. Comp. Graphics International, Virtual Reality and Intelligent Hardware, 5(6), pp. 550-564, https://doi.org/10.1016/j.vrih.2023.06.001, 2023.
• I. Evangelou, G. Papaioannou, K. Vardis, A. Gkaravelis, A neural builder for spatial subdivision hierarchies, The Visual Computer, 39, pp. 3797–3809, https://doi.org/10.1007/s00371-023-02975-y, 2023.
• N. Vitsas, I. Evangelou, G. Papaioannou, A. Gkaravelis, Parallel Transformation of Bounding Volume Hierarchies into Oriented Bounding Box Trees, Computer Graphics Forum (Proc. Eurographics), 42(2), pp. 245-254, 2023.
• I. Evangelou, A. Gkaravelis, G. Papaioannou, Real-Time Volume Editing on Low-Power Virtual Reality Devices, Proc. 18th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (GRAPP), 2023.

2022

• A. Benardou, A. M. Droumpouki, G. Papaioannou, First-person Interactive Experience of a Concentration Camp: The Case of Block 15, Difficult Heritage and Immersive Experiences (A. Benardou, A. M. Droumpouki - Eds.), ISBN 9781032060866, Routledge, pp. 145 - 160, 2022.
• P. Platanou, J. Pavlopoulos, G. Papaioannou, Handwritten Paleographic Greek Text Recognition: A Century-Based Approach, Proc. Conference on Language Resources and Evaluation (LREC 2022), pp. 6585–6589, 2022.

2021

• A. A. Vasilakis, G. Papaioannou, N. Vitsas, A. Gkaravelis, Remote Teaching Advanced Rendering Topics Using the Rayground Platform, IEEE Computer Graphics and Applications, 41(5), p. 99-103, 2021.
• I. Evangelou, N. Vitsas, G. Papaioannou, M. Georgioudakis, A. Chatzisymeon, Shape Classification of Building Information Models using Neural Networks, short paper, Proc. Eurographics Workshop on 3D Object Retrieval (3DOR), 2021.
• N. Vitsas, A. Gkaravelis, A. A. Vasilakis, G. Papaioannou, WEBRAYS: Ray Tracing on the Web, Ray Tracing Gems II, A. Marrs (Ed.), P. Shirley (Ed.), I. Wald (Ed.), ISBN 978-1-4842-4427-2, p. 281-299, 2021.
• N. Vitsas, K. Vardis, G. Papaioannou, Sampling Clear Sky Models using Truncated Gaussian Mixtures, Proc. Eurographics Symposium on Rendering, 2021.
• K. Vardis, A. A. Vasilakis, G. Papaioannou, Illumination-driven Light Probe Placement, Proc. Eurographics 2021, poster.
• I. Evangelou, G. Papaioannou, K. Vardis, and A. A. Vasilakis, Fast Radius Search Exploiting Ray Tracing Frameworks, Journal of Computer Graphics Techniques (JCGT), vol. 10(1), pp. 25-48, 2021. Available online at: http://jcgt.org/published/0010/01/02/.
• I. Evangelou, M. Savelonas, G. Papaioannou, PU learning-based recognition of structural elements in architectural floor plans. Multimedia Tools & Applications, 2021. https://doi.org/10.1007/s11042-020-10295-9.

2020

• I. Evangelou, G. Papaioannou, K. Vardis, A. A. Vasilakis, Rasterisation-based progressive photon mapping. The Visual Computer, 2020. The final publication is available at link.springer.com, https://doi.org/10.1007/s00371-020-01897-3.
• N. Vitsas, G. Papaioannou , A. Gkaravelis, A. A. Vasilakis, Illumination-guided Furniture Layout Optimization, Computer Graphics Forum (Proc. Eurographics), 39 (2), 2020.
• A. A. Vasilakis and K. Vardis, G. Papaioannou, A Survey of Multifragment Rendering, Computer Graphics Forum (Proc. Eurographics - STARs), 39(2), 2020.
• N. Vitsas, A. Gkaravelis, A. A. Vasilakis , K. Vardis, G. Papaioannou, Rayground: An Online Educational Tool for Ray Tracing, Proc. Eurographics (education papers), 2020.

2019

• G. Papaioannou, I. Koutsopoulos, Tile-based Caching Optimization for 360° Videos, Proc. ACM International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc),2019.

2018

• A. Gkaravelis, G. Papaioannou, Light Optimization for Detail Highlighting, Computer Graphics Forum (proc. Pacific Graphics 2018), 37(7), pp. 37-44, October, 2018.
• P. Mavridis, G. Papaioannou, Practical Elliptical Texture Filtering on the GPU, GPU Pro 360 Guide to Rendering, 1st edition, W. Engel (Ed.), book chapter, A K Peters/CRC Press, ISBN 9780815365501, p. 161-173, 2018.
• A. Gaitatzes, G. Papaioannou, Progressive Screen-Space Multichannel Surface Voxelization, GPU Pro 360 Guide to Rendering, 1st edition, W. Engel (Ed.), book chapter, A K Peters/CRC Press, ISBN 9780815365501, pp. 299-315, 2018.
• I. Pratikakis, M. Savelonas, P. Mavridis, G. Papaioannou, K. Sfikas, F. Arnaoutoglou, D. Rieke-Zapp, Predictive Digitisation of Cultural Heritage Objects, Multimedia Tools and Applications, Springer, 77(10), pp. 12991-13021, May, 2018.

2017

• M. A. Savelonas, A. Andreadis, G. Papaioannou, P. Mavridis, Exploiting Unbroken Surface Congruity for the Acceleration of Fragment Reassembly, Proc. EUROGRAPHICS Workshop on Graphics and Cultural Heritage, 2017.
• A. A. Vasilakis, K. Vardis, G. Papaioannou, K. Moustakas, Variable k-Buffer using Importance Maps, Proc. Eurographics 2017, short paper track, 2017.
• A. Gkaravelis, G. Papaioannou, Detail Highlighting using a Shadow Edge Histogram, Proc. Eurographics 2017, short paper track, 2017.
• G. Papaioannou, T. Schreck, A. Andreadis, P. Mavridis, R. Gregor, I. Sipiran, K. Vardis, From Reassembly to Object Completion: A Complete Systems Pipeline. ACM Journal on Computing and Cultural Heritage, 10(2), Article 8, DOI: http://dx.doi.org/10.1145/3009905, 2017

2016

• K. Vardis, A. Vasilakis, G. Papaioannou, DIRT: Deferred Image-based Ray Tracing, proc. High Performance Graphics, 2016.
• A. Gkaravelis, G. Papaioannou, Inverse Lighting Design using a Coverage Optimization Strategy, Visual Computer (proc. CGI 2016), Springer, DOI 10.1007/s00371-016-1237-9, 2016.
• K. Kalampokis, G. Papaioannou, A. Gkaravelis, A Generic Physically-based Approach to the Opening Design Problem, Proc. Eurographics 2016 (short paper), 2016.
• A. Andeadis, G. Papaioannou, P. Mavridis, GPU Accelerated Computation of Geometric Descriptors in Parametric Space (chapter), In book Computer Vision, Imaging and Computer Graphics Theory and Applications, Springer, pp 41-61, 2016.
• K. Vardis, A. Vasilakis, G. Papaioannou, A Multiview and Multilayer Approach for Interactive Ray Tracing, Proc. ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (i3D 2016), pp. 171-178, 2016.

2015

• P. Mavridis, I. Sipiran, A. Andreadis, G. Papaioannou, Object Completion using k-Sparse Optimization, Computer Graphics Forum (proc. Pacific Graphics), vol. 34, no. 7, 2015.
• A. Andreadis, G. Papaioannou, P. Mavridis, Generalized Digital Reassembly using Geometric Registration, Proc. IEEE/ACM Digital Heritage 2015.
• P. Mavridis, G. Papaioannou, MSAA-Based Coarse Shading for Power-Efficient Rendering on High Pixel-Density Displays, High Performance Graphics (quick talk, poster), 2015.
• A. Andreadis, R. Gregor, I. Sipiran, P. Mavridis, G. Papaioannou, T. Schreck, Fractured 3D Object Restoration and Completion, ACM SIGGRAPH 2015 Poster.
• A. A. Vasilakis, G. Papaioannou, I. Fudos, k+-buffer: An Efficient, Memory-Friendly and Dynamic k-buffer Framework, IEEE Transactions on Visualization and Computer Graphics, 2015.
• P. Mavridis, A. Andreadis, G. Papaioannou, Efficient Sparse ICP, Computer Aided Geometric Design (Proc. Geometric Modeling and Processing), vol. 35–36, pp. 16-26, 2015.
• A. A. Vasilakis, G. Papaioannou, Improving k-buffer methods via Occupancy Maps, Eurographics 2015 (short paper).
• P. Mavridis, A. Andreadis, G. Papaioannou, Fractured Object Reassembly via Robust Surface Registration, Eurographics 2015 (short paper).
• A. A. Vasilakis, G. Papaioannou, Accelerating k+-buffer using efficient fragment culling, Proc. 19th Symposium on Interactive 3D Graphics and Games (i3D - poster). ACM, San Francisco, California, pp. 129, 2015 (poster abstract).
• A. Gkaravelis, G. Papaioannou, K. Kalampokis, Inverse Light Design for High-Occlusion Environments, proc. GRAPP 2015.
• A. Andreadis, G. Papaioannou, P. Mavridis, A Parametric Space Approach to the Computation of Multi-Scale Geometric Features, proc. GRAPP 2015.

2014

• K. Vardis, G. Papaioannou, A. Gkaravelis, Real-time Radiance Caching using Chrominance Compression, Journal of Computer Graphics Techniques (JCGT), 3(4), pp. 111-131, 2014.
• R. Gregor, Sipiran, I., Papaioannou, G., Schreck, T., Andreadis, A., and Mavridis, P., Towards Automated 3D Reconstruction of Defective Cultural Heritage Objects, Proc. Eurographics Workshop on Graphics and Cultural Heritage. pp. 135-144, 2014.
• A. Andreadis, P. Mavridis, G. Papaioannou, Facet Extraction and Classification for the Reassembly of Fractured 3D Objects, Eurographics poster. Strasbourg, 2014.

2013

• T. Theoharis, G. Papaioannou, K. Bjørlykke, Ø. Ekroll, D. Riekke-Zapp, A. Lein, A. Andreadis, Multi-scale 3D Digitization at Nidaros Cathedral: From Archiving to Large-scale Visualization, 18th Conference on Cultural Heritage and New Technologies. 2013.
• S. Katsigiannis, G. Papaioannou, D. Maroulis, A GPU-based Real-time Video Compression Method for Video Conferencing. Proc. 18th IEEE/EURASIP Int. Conf. on Digital Signal Processing (DSP2013), 2013.
• P. Mavridis, G. Papaioannou, Practical Frame Buffer Compression, GPU Pro 4. CRC Press, 2013.
• A. Gaitatzes, G. Papaioannou, Progressive Screen-space Multi-channel Surface Voxelization, GPU Pro 4. CRC Press, 2013.
• K. Vardis, G. Papaioannou, A. Gaitatzes,Multi-view Ambient Occlusion with Importance Sampling. Proc. ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (i3D 2013), pp. 111-118.
• S. Katsigiannis, G. Papaioannou, D. Maroulis. A Real-Time Video Encoding Scheme Based on the Contourlet Transform, Design and Architectures for Digital Signal Processing, Dr. Gustavo Ruiz (Ed.), ISBN: 978-953-51-0874-0, InTech, 2013.

2012

• P. Mavridis, G. Papaioannou, The Compact YCoCg Frame Buffer, Journal of Computer Graphics Techniques, 1(1), 19-35, 2012.
• P. Mavridis, G. Papaioannou, Texture Compression using Wavelet Decomposition, Computer Graphics Forum (Proc. Pacific Graphics 2012), 31(7), 2012.
• S. Katsigiannis, G. Papaioannou, D. Maroulis, A Contourlet Transform based algorithm for real-time video encoding, SPIE Photonics Europe, Real-Time Image and Video processing Conference, 16-19 April, Brussels, Belgium, 2012 (best student paper award).
• P. Mavridis, G. Papaioannou, Practical Elliptical Texture Filtering, GPU Pro 3. A. K. Peters/CRC Press, 2012.
• P. Mavridis, G. Papaioannou, Texture compression using wavelet decomposition: A preview. Poster, Proc. I3D 2012: ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, p. 218.

2011

• A. Gaitatzes, P. Mavridis, G. Papaioannou, Two Simple Single-pass GPU methods for Multi-channel Surface Voxelization of Dynamic Scenes, Proc. Pacific Graphics 2011.
• G. Papaioannou, Real-Time Diffuse Global Illumination Using Radiance Hints, Proc.ACM SIGGRAPH Symposium on High Performance Graphics (HPG '11), pp. 15-24.
• P. Mavridis, G. Papaioannou, Global Illumination Using Imperfect Volumes. Proc. GRAPP 2011.
• P. Mavridis, G. Papaioannou, High Quality Elliptical Texture Filtering on GPU, Proc. 2011 ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D 2011), San Francisco, CA, USA, pp. 23-30, 2011.

2010

• P. Mavridis, A. Gaitatzes, G. Papaioannou, Volume-based Diffuse Glocal Illumination. Proc. CGVCVIP ’10: Proceedings of Computer Graphics, Visualization, Computer Vision and Image Processing 2010.
• A. Gaitatzes, P. Mavridis, G Papaioannou, Interactive Volume-based Indirect Illumination of Dynamic Scenes, Proc. 3IA’10: Proceedings of the 2010 International Conference on Computer Graphics and Artificial Intelligence, May 2010.
• P. Papiotis, G. Papaioannou, Kettle: A Real-time model for Orchestral Timpani, Proc. Sound and Music Computing 2010, Barcelona, Spain.
• G. Papaioannou, M. L. Menexi, C. Papadopoulos, Real-Time Volume-Based Ambient Occlusion, IEEE Transactions on Visualization and Computer Graphics, pp. 752-762, September/October, 2010.
• A. Gaitatzes, A. Andreadis, G. Papaioannou, Y. Chrysanthou, Fast Approximate Visibility on the GPU Using Precomputed 4D Visibility Fields, Proc. WSCG 2010, pp. 131-138, 2010.

2009

• C. Papadopoulos, G. Papaioannou, Realistic Real-time Underwater Caustics and Godrays, Proc. GraphiCon '09, pp. 89-95, 2009.
• C. Koniaris, A. Gaitatzes, G. Papaioannou, An Automated Modeling Method for Multiple Detail Levels Of Real-time Trees, Proc. IEEE Int. conf. Games and Virtual Worlds for Serious Applications, pp.53-60, 2009.

2008

• A. Gaitatzes, Y. Chrysanthou, G. Papaioannou, Presampled Visibility for Ambient Occlusion, Proc. WSCG 2008, Journal of WSCG, 16(1-3), pp. 17-24, 2008.

2007

• P. Stavrou, G. Papaioannou, T. Theoharis, Mending Fractured Models Using Surface Patches, Proc. 10th Computer Graphics and Artificial Intelligence Conference, Athens, May 2007.

2006

• D. Christopoulos, A. Gaitatzes, G. Papaioannou, G. Zyba, Designing a Real-time Playback System for a Dome Theater, Proc. Eurographics 7th International Symposium on Virtual Reality, Archaeology and Intelligent Cultural Heritage VAST, pp. 35-40, 2006.
• A. Gaitatzes, G. Papaioannou, D. Christopoulos, G. Zyba, Media Productions for a Dome Display System, Proc. ACM Symposium on Virtual Reality Software and Technology (VRST) 2006, pp. 261-264, 2006.
• G. Papaioannou, A. Gaitatzes, D. Christopoulos, Efficient Occlusion Culling using Solid Occluders. Proceedings of the 14-th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision (WSCG '2006), pp. 85-93, 2006.
• P. Stavrou, P. Mavridis, G. Papaioannou, G. Passalis, T. Theoharis, 3D Object Repair Using 2D Algorithms, Proc. International Conference on Computational Science 2006 (ICCS 2006), LNCS, Springer.

2005

• A. Gaitatzes, D. Christopoulos, G. Papaioannou, Virtual Reality Systems and Applications: The Ancient Olympic Games. Proc. 10th Panhellenic Conference on Informatics (PCI'05), Springer LNCS 3746, pp. 155-165.
• G. Papaioannou, Interactive Dynamics for Large Virtual Reality Applications, Proc. 10th Panhellenic Conference on Informatics (PCI'05), LNCS 3746, pp. 307-316, 2005.

2004

• A. Gaitatzes, D. Christopoulos, G. Papaioannou, The Ancient Olympic Games: Being Part of the Experience, Proc. Eurographics 5th International Symposium on Virtual Reality, Archaeology and Intelligent Cultural Heritage (VAST), pp. 19-28, 2004.
• N. Vajramushti, I. A. Kakadiaris, T. Theoharis, G. Papaioannou, Efficient 3D Object Retrieval Using Depth Images, 6th ACM SIGMM International Workshop on Multimedia Information Retrieval (ACM SIGMM MIR '04), New York, USA, pp. 189-196, 2004.

2003

• G. Papaioannou, E. A. Karabassi, On the Automatic Assemblage of Arbitrary Broken Solid Artefacts, Image & Vision Computing, Elsevier, 21(5), pp. 401-412, 2003.
• E. A. Karabassi, G. Papaioannou, C. Fretzagias and T. Theoharis, Exploiting Multiresolution Models to Accelerate Ray Tracing, Computers & Graphics, Elsevier, 27(1), pp. 91-98, 2003. 
• G. Papaioannou, A. Gaitatzes, D. Christopoulos, Enhancing Virtual Walkthroughs of Archaeological Sites, Proc. Eurographics 4th International Symposium on Virtual Reality, Archaeology and Intelligent Cultural Heritage (VAST), pp. 175-184, 2003.
• G. Papaioannou, T. Theoharis, Fast Fragment Assemblage Using Boundary Line and Surface Matching, IEEE ICPR/ACVA 2003 proceedings.
• D. Christopoulos, A. Gaitatzes, G. Papaioannou, Image-based Techniques for Enhancing Virtual Reality Environments, Proc. of 2nd International Workshop on ICT's, Arts and Cultural Heritage, Athens, Greece, 2003.

2002

• G. Papaioannou, E.A. Karabassi, T. Theoharis, Reconstruction of Three-dimensional Objects through Matching of their Parts, IEEE Transactions on Pattern Analysis and Machine Intelligence, 24(1), pp.114-124, 2002.

2001

• G. Papaioannou, E.A. Karabassi, T. Theoharis, Virtual Archaeologist: Assembling the Past, IEEE Computer Graphics and Applications, 21(2), pp. 53-59, 2001. 
• T. Theoharis, G. Papaioannou, E. A. Karabassi, The Magic of the Z-Buffer: A Survey, Proceedings of the 9-th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision (WSCG '2001), pp. 379-386, 2001.

2000

• G. Papaioannou, E.A. Karabassi, T. Theoharis, Segmentation and Surface Characterization of Arbitrary 3D Meshes for Object Reconstruction and Recognition, Proceedings of the International Conference on Pattern Recognition ‘2000, IEEE, 2000, pp. 734-737.
• G. Papaioannou, E.A. Karabassi, T. Theoharis, Automatic Reconstruction of Archaeological Finds - A Graphics Approach, Proc. of the 4th International Conference on Computer Graphics and Artificial Intelligence (3IA' 2000), Limoges, France, pp117-125, 2000.
• M. Hatzitheodorou, A. Karabassi, G. Papaioannou, A. Boehm, T. Theoharis, Stereo Matching Using Optic Flow, Real Time Imaging, Academic Press, 6(4), pp. 251-266, 2000.

1999

• E.A. Karabassi, G. Papaioannou, T. Theoharis, A Fast Depth Buffer Based Voxelization Algorithm, Journal of Graphics Tools, ACM, 4(4), pp.5-10, 1999.
• E. A. Karabassi, G. Papaioannou, Th. Theoharis, Intersection Test for Collision Detection in Particle Systems, Journal of Graphics Tools, ACM, 4(1), pp 25-37, 1999.

1998

• G. Papaioannou, T. Theoharis, A. Boehm, A Texture Controller, The Visual Computer, Springer-Verlag, 14(10), pp 488-496, 1998.

• Graphics and Visualization: Principles & Algorithms, T. Theoharis, G. Papaioannou, N. Platis, N. M. Patrikalakis, Symmetria, GR, 2010.
• Graphics and Visualization: Principles & Algorithms, T. Theoharis, G. Papaioannou, N. Platis, N. M. Patrikalakis, AK Peters, USA, 2008.
• Graphics: Principles and Algorithms, T. Theoharis and A. Boem, Symmetria, 1999 (Greek computer graphics textbook - chapters).

• Stamos Katsigiannis, Georgios Papaioannou, Dimitris Maroulis,  CVC: The Contourlet Video Compression algorithm for real-time applications, arXiv.org, 2015
• A. A. Vasilakis, K. Vardis, A. Gkaravelis, G. Papaioannou, K. Kalampokis, State of the Art Report on Interactive Global Illumination Techniques and Inverse Lighting Problems, GLIDE project, 2014.
• Georgios Papaioannou, A Simple and Fast Technique for Fur Rendering, Tech. Report, Department of Informatics & Telecommunications, National and Kapodistrian University of Athens, 2002.
• Georgios Papaioannou, Evaggelia-Aggeliki Karabassi, Semiautomatic Vessel Isolation in Vascular Angiography, Tech. Report, Department of Informatics, National and Kapodistrian University of Athens, 1999.

• G. Papaioannou, Automatic Reconstruction of Objects from their Parts and its Application to Digital Archaeology, Ph.D. Dissertation (in Greek), Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, Greece, 2001.

• T. Theoharis, G. Papaioannou, P. Mavridis, A. Andreadis, M. Savelonas, I. Sipiran, P. Perakis, C. Schelewald, D. R. Zapp, workshop on Predictive Techniques for 3D Data Augmentation in Cultural Heritage, Computer Applications and Quantitative Methods in Archaeology (CAA), 2015.
• A. Gaitatzes, G. Papaioannou, and D. Christopoulos. 2006. Virtual reality systems and applications. In Proceedings of the ACM symposium on Virtual reality software and technology (VRST '06). ACM, New York, NY, USA, pp. 384.