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• Curriculum Vitae

DI Dr. Stefan Lengauer

About

Senior Researcher at the Institute of Visual Computing (IVC), Graz University of Technology.

Research Interests:

• Visual analytics
• Visualization
• Similarity search
• Cultural heritage,
• Image processing

Contact:

• Address: Inffeldgasse 16, 8010 Graz, AUSTRIA
• Email: s.lengauer@tugraz.at
• Phone (TU Graz): +43 316 873 - 5407
• Platforms: Scholar, ORCiD, ResearchGate DBLP Github

Ongoing Projects:

• (Since 2024) HEREDITARY: HetERogeneous sEmantic Data integratIon for the guT-bRain interplaY
• (Since 2020) A⁺CHIS: Novel Concepts and Testbed Systems for Visual Adaptive Consumer Health Information.

Publications

• Journal Article (9)
• Conference or Workshop Paper (17)
• Book chapter (1)
• Poster or demo (8)
• Other Publication (1)
• Awards (4)

2026

• [c17] Tytarenko, M., Atzberger, D., Bedek, M., Lengauer, S., Schreck, T., "Confirmation Bias Awareness in Visual Information Retrieval via LLM-Guided Interaction-Trace Monitoring," in 2026 IEEE 19th Pacific Visualization Conference (PacificVis), 2026.
• [c16] Tytarenko, M., Söls, C., Atzberger, D., Lengauer, S., Schreck, T., "Eye-Tracking Support for Adaptive Document Exploration: Design Space Model and Application Examples," in 21st International Conference on Computer Graphics, Interaction and Visualization Theory and Applications: GRIVAPP 2026, 2026.
• [j9] Lengauer, S., Shao, L., Miri, H., Bedek, M., Kupfer, C., Zangl, M., Kubicek, B., Dienstbier, B., Jeitler, K., Krenn, C., Semlitsch, T., Zipp, C., Albert, D., Siebenhofer, A., Schreck, T., "A Visual Approach for Health Information Exploration: Adaptive Levels of Visual Granularity and Interaction Analysis," Journal of Universal Computer Science (J.UCS), 32(1), 2026, pp.4-32. 10.3897/jucs.150679
  pdf preprint bibtex

2025

• [p8] Kantz, B., Waldert, P., Lengauer, S., Schreck, T. "Visual Exploration of Ontologies Supported by Language Models and Interactive Lenses" 18th International Symposium on Visual Information Communication and Interaction (VINCI), 2025.
• [c15] Lengauer, S., Götz, S. A., Hoesch, M. T., Steinwidder, F., Bedek, M., Schreck, T., "GUIDÆTA — A Versatile Interactions Dataset with extensive Context Information and Metadata" Smart Tools and Applications in Graphics - Eurographics Italian Chapter Conference, 2025. 10.2312/stag.20251335
  pdf bibtex presentation dataset code
• [c14] Kantz, B., Innerebner, K., Waldert, P., Lengauer, S., Lex, E., Schreck, T. "Graph Queries from Natural Language using Constrained Language Models and Visual Editing" 2025 IEEE International Conference on Knowledge Graph (ICKG), 2025.
• [c13] Tytarenko, M., Rutar, T. W., Lengauer, S., Schreck, T. "LLM-Agent Support for Two-Document Comparison Using Hierarchical Topic Maps" 1st Workshop on GenAI, Agents, and the Future of VIS @ IEEE VIS, 2025.
  pdf
• [p7] Kantz, B., Lengauer, S., Waldert, P., Schreck, T. "AlloyInter: Visualising Alloy Mixture Interpolations in t-SNE Representations" SciVis Challenge @ IEEE VIS, , 2025.
  Most Innovative Approach
  bibtex
• [p6] Kantz, B., Lengauer, S., Waldert, P., Schreck, T. "Constrained Linked Entity ANnotation using RAG (CLEANR)" BioASQ Task GutBrainIE, 2025.
• [p5] Kantz, B., Innerebner, K., Waldert, P., Lengauer, S., Lex, E., Schreck, T. "OnSET: Ontology and Semantic Exploration Toolkit, " in Proceedings of the 48th International ACM SIGIR Conference on Research and Development in Information Retrieval, 2025 (Demo), 2025.
  bibtex
• [p4] Lengauer, S., Proprentner, F., Tytarenko, M., Krenn, C., Jeitler, K., Schreck, T. "Automatische Beantwortung von Gesundheitsfragen durch generative KI mittels Retrieval Augmented Generation – Vergleich und Potentiale von Großen Sprachmodellen anhand des Beispiels Diabetes mellitus Typ 2," 26. Jahrestagung des Deutschen Netzwerks Evidenzbasierte Medizin, Freiburg, 2025.
  poster presentation
• [c12] Tytarenko, M., Burtscher, C.W., Atzberger, D., Jobst, A., Scheibl, W., Lengauer, S., Schreck, T. "A User-Centric Adaption Model for Document Visualizations with Different Levels of Detail," in Proceedings of the 30th International Conference on Intelligent User Interfacese, 2025.
  pdf presentation bibtex

2024

• [j8] Vergara , M., Bustos, B., Sipiran, I., Schreck, T., Lengauer, S., "Multi-label learning on low label density sets with few examples," Expert Systems with Applications, 2024. 10.3389/fpubh.2024.1252244
  bibtex
• [p3] Lengauer, S., Waldert, P., Schreck, T., "Droplets: A Marker Design for visually enhancing Local Cluster Association" in BioMed+VIS Challenge @ IEEE VIS, 2024. 10.5281/zenodo.14049796
  Best Challenge Entry: Novelty
  pdf poster video bibtex
• [c11] Houska, P., Masur, A., Kloiber, S., Lengauer, S., Karl, S., Preiner, R. "Computer-Assisted Collaborative Fragment Matching of Incomplete Stone Artifacts," in Eurographics Workshop on Graphics and Cultural Heritage, The Eurographics Association, 2024. 10.2312/gch.20241244
  Best Paper
  pdf bibtex
• [p2] Lengauer, S., Shao, L., Tytarenko, M., Klaffenböck, M., Schreck, T., "Interaction Visualization for Analysing and Improving User Models" in 32nd ACM Conference on User Modeling, Adaptation and Personalization (UMAP), 2024. 10.1145/3631700.3664877
  pdf poster video bibtex
• [c10] Tytarenko, M., Shao, L., Rutar, T. W., Bedek, M. A., Krenn, C., Lengauer, S., Schreck, T. "Hierarchical Topic Maps for Visual Exploration and Comparison of Documents," in EuroVis Workshop on Visual Analytics (EuroVA), The Eurographics Association, 2024. 10.2312/eurova.20241119
  pdf bibtex
• [b1] Trinkl, E., Karl, S., Lengauer, S., Preiner, R., Schreck, T., "Cross-modal search and exploration of greek painted pottery," in The 3 Dimensions of Digitalised Archaeology. State-of-the-art, Data Management and Current Challenges in Archaeological 3D Documentation, Cham: Springer International Publishing, 2024, pp. 109–128. 10.1007/978-3-031-53032-6_7
  bibtex
• [j7] Krenn, C., Semlitsch, T., Zipp, C., Lengauer, S., Shao, L., Schreck, T., Bedek, M., Kupfer, C., Albert, D., Kubicek, B., Siebenhofer, A., Jeitler, K., "Customization options in consumer health information materials on type 2 diabetes mellitus – an analysis of modifiable features in different types of media," Frontiers in public health, vol. 12, p. 1 252 244, 2024. 10.3389/fpubh.2024.1252244
  pdf bibtex

2023

• [j6] Lengauer, S., Shao, L., Mayerhofer, M., Preiner, R., Karl, S., Trinkl, E., Sipiran, I., Bustos, B., Schreck, T., "Visual Exploration of Repetitive Patterns on Ancient Peruvian Pottery," Journal of WSCG, vol. 31, pp. 25–33, 2023. 10.24132/JWSCG.2023.3
  pdf bibtex
• [c9] Lengauer, S., Bedek, M., Kupfer, C., Shao, L., Albert, D., Schreck, T., "Recognizing user behavior from interactions for adaptive consumer information systems," in International Conference on Interactive Media, Smart Systems and Emerging Technologies (IMET), The Eurographics Association, 2023. 10.2312/imet.20231251
  pdf bibtex
• [c8] Shao, L., Lengauer, S., Miri, H., Bedek, M., Kubicek, B., Kupfer, C., Zangl, M., Dienstbier, B., Jeitler, K., Krenn, C., Semlitsch, T., Zipp, C., Albert, D., Siebenhofer, A., Schreck, T., "Visual document exploration with adaptive level of detail: Design, implementation and evaluation in the health information domain," in 18th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications: VISIGRAPP 2023, SciTePress-Science and Technology Publications, vol. 3, 2023, pp. 133–141. 10.5220/0011621800003417
  pdf bibtex
• [p1] Houska, P., Kloiber, S., Masur, A., Lengauer, S., Karl, S., Preiner, R., "Towards crowd-sourced collaborative fragment matching," in Eurographics Workshop on Graphics and Cultural Heritage, The Eurographics Association, 2023. 10.2312/gch.20231180
  pdf flyer poster bibtex

2022

• [c7] Lengauer, S., Preiner, R., Sipiran, I., Karl, S., Trinkl, E., Bustos, B., Schreck, T., "Context-based Surface Pattern Completion of Ancient Pottery," in Eurographics Workshop on Graphics and Cultural Heritage, The Eurographics Association, 2022. 10.2312/gch.20221234
  pdf bibtex
• [c6] Lengauer, S., Houska, P., Preiner, R., "Efficient Point Cloud Skeletonization with Locally Adaptive L1-Medial Projection," Computer Science Research Notes, vol. 3201, pp. 38–47, 2022. 10.24132/CSRN.3201.6
  pdf bibtex
• [j5] Lengauer, S., Houska, P., Preiner, R., Trinkl, E., Karl, S., Sipiran, I., Bustos, B., Schreck, T., "Interactive annotation of geometric ornamentation on painted pottery assisted by deep learning," it - Information Technology, vol. 64, no. 6, pp. 217–231, 2022. 10.1515/itit-2022-0007
  pdf bibtex
• [j4] Karl, S., Houska, P., Lengauer, S., Haring, J., Trinkl, E., Preiner, R., "Advances in digital pottery analysis," it - Information Technology, vol. 64, no. 6, pp. 195–216, 2022. 10.1515/itit-2022-0006
  pdf bibtex

2021

• [j3] Sipiran, I., Lazo, P., Lopez, C., Jimenez, M., Bagewadi, N., Bustos, B., Dao, H., Gangisetty, S., Hanik, M., Ho-Thi, N.-P., Holenderski, M., Jarnikov, D., Labrada, A., Lengauer, S., Licandro, R., Nguyen, D.-H., Nguyen-Ho, T.-L., Perez Rey, L. A., Pham, B.-D., Pham, M.-K., "Shrec 2021: Retrieval of cultural heritage objects," Computers & Graphics, vol. 100, pp. 1–20, 2021. 10.1016/j.cag.2021.07.010
  bibtex
• [c5] Houska, P., Lengauer, S., Karl, S., Preiner, R., "Direct Elastic Unrollings of Painted Pottery Surfaces from Sparse Image Sets," in Eurographics Workshop on Graphics and Cultural Heritage, The Eurographics Association, 2021. 10.2312/gch.20211417
  pdf bibtex
• [j2] Lengauer, S., Sipiran, I., Preiner, R., Schreck, T., Bustos, B., "A Benchmark Dataset for Repetitive Pattern Recognition on Textured 3D Surfaces," Computer Graphics Forum, 2021. 10.1111/cgf.14352
  pdf dataset video bibtex

2020

• [j1] Lengauer, S., Komar, A., Labrada, A., Karl, S., Trinkl, E., Preiner, R., Bustos, B., Schreck, T., "A sketch-aided retrieval approach for incomplete 3d objects," Computers & Graphics, vol. 87, pp. 111–122, 2020. 10.1016/j.cag.2020.02.001
  pdf bibtex
• [c4] Lengauer, S., Komar, A., Karl, S., Trinkl, E., Sipiran, I., Schreck, T., Preiner, R., "Semi-automated Annotation of Repetitive Ornaments on 3D Painted Pottery Surfaces," in Eurographics Workshop on Graphics and Cultural Heritage, The Eurographics Association, 2020, pp. 1–4. 10.2312/gch.20201285
  Honorable Mention in the category "Impact on Society" at the "Computer Graphics Night 2020" by Fraunhofer IGD, Darmstadt
  pdf video bibtex
• [c3] Lengauer, S., Komar, A., Karl, S., Trinkl, E., Preiner, R., Schreck, T., "Visual Exploration of Cultural Heritage Collections with Linked Spatiotemporal, Shape and Metadata Views," in Vision, Modeling, and Visualization, The Eurographics Association, 2020. 10.2312/3dor.20191057
  pdf spotlight presentation bibtex

2019

• [o1] Schreck, T., Lengauer, S., Preiner, R., "Forschungsprojekt crossmodale suche und visuelle exploration von 3d kulturgutobjekten," in Forum Archaeologiae, vol. 91, 2019
  pdf bibtex
• [c2] Lengauer, S., Komar, A., Labrada, A., Karl, S., Trinkl, E., Preiner, R., Bustos, B., Schreck, T., "Motif-driven retrieval of greek painted pottery," in Eurographics Workshop on Graphics and Cultural Heritage, Eurographics-European Association for Computer Graphics, The Eurographics Association, 2019, pp. 91–98. 10.2312/gch.20191354
  pdf bibtex
• [c1] Lengauer, S., Komar, A., Labrada, A., Karl, S., Trinkl, E., Preiner, R., Bustos, B., Schreck, T., "Sketch-Aided Retrieval of Incomplete 3D Cultural Heritage Objects," in Eurographics Workshop on 3D Object Retrieval, The Eurographics Association, 2019, pp. 17–24. 10.2312/3dor.20191057
  pdf bibtex

Teaching

Students

BSc. Students:

1. Andi Kondi (co-advised with Benedikt Kantz): "Underlay Visibility Enhancement in Images through Overlay Minimization." 2026.
2. Giuliano Privoznik (co-advised with Mariia Tytarenko): "Semantic Annotation in consumer health information." 2025.
3. Mateo Bajkuša: "Behavior Modelling in Consumer Health Information Systems." 2025.
4. Christian Wolfgang Burtscher (co-advised with Tobias Schreck and Mariia Tytarenko): "Adaptive Visual Health Information." 2024. (Later published in a peer-reviewed journal [c12]).
5. Patrick Balent: "Deep Learning for Geometric Pattern Recognition in Cultural Heritage." (ongoing).
6. Vladimir Sandić (co-advised with Lin Shao and Mariia Tytarenko): "Medical Chatbot for Diabetes." 2024.
7. Florian Wachter (co-advised with Tobias Schreck and Volker Settgast): "Augmented and Mixed Reality Applications for Ancient Pottery." 2022.
8. Fabian Proprentner (co-advised with Lin Shao and Mariia Tytarenko): "Chatbots for Health Information." 2024. (Later published in a poster [p4]).
9. Alexander Vordermeier (co-advised with Tobias Schreck): "Graph-based Comparison of 3D Building Objects." 2021.
10. Daniel Bruncic (co-advised with Tobias Schreck): "A System for Visual Exploration and Analysis of 3D Building Models." 2021.
11. Markus Schleifer (co-advised with Tobias Schreck): "Sketch-Interface for Similarity Search." 2021.

MSc. Students:

1. Armin Weiss: "Migrating Annotations in PDF Documents over the Document Life cycle." 2026.
2. Joseph Juri (co-advised with Peter Houska): "CNN-Based Depth Estimation for Direct Elastic Unrolling of Painted Pottery Surfaces." 2025.
3. Christoph Söls (co-advised with Tobias Schreck): "Eye Tracking in Adaptive Visual Exploration." (ongoing).
4. Magdalena Mayerhofer (co-advised with Tobias Schreck): "Multimodal Visualization and Exploration of CH Data." 2022. (Later published in a peer-reviewed journal [j6]).
5. Thomas Leh (co-advised with Tobias Schreck): "Visual Exploration of 3D CH Repositories." 2023.

I kindly ask students who submit their theses for feedback to ensure that their work is free from the these [frequent-errors-in-scientific-writing].

Courses

• (2020 – Current) [700.200] Introduction to Scientific Working (as Lecturer/Teaching Assistant)
• (2019 – 2025) [711.010] Digital Libraries (as Teaching Assistant)
• (2019 – 2021) [711.027] 3D Object Retrieval (as Teaching Assistant)

Curriculum Vitae

Obtained Degrees

• (2018 – 2022) Ph.D., Graz University of Technology in Computer Science (Graduated with distinction).
  Thesis: "Crossmodal Search, Visual Exploration, and Restoration of Digital Pottery Artifacts"
  pdf bibtex
• (2015 – 2018) MSc., Graz University of Technology in Space Sciences.
  Thesis: "SLR Validation for Kinematic Orbit Determination"
  pdf bibtex
• (2014 – 2022) BSc., Graz University of Technology in Computer Science.
  Thesis: "Efficient Point Cloud Skeletonization with Locally Adaptive L1-Medial Projection"
  (Later published in a peer-reviewed journal [c6])
• (2012 – 2015) BSc., FH JOANNEUM University of Applied Sciences in Aviation.
  Thesis: "Large Eddy Simulation of Heat Transfer on Wing surfaces in 3D"

Current & Recent Projects (Positions)

• (2024 – Current) HEREDITARY, Project Assistant.
  HORIZON Europe Project HetERogeneous sEmantic Data integratIon for guT-bRain interplaY, together with 16 international research organizations.
  url
• (2022 – Current) A⁺CHIS, Project Assistant.
  FWF Research Group on Human-Centered Interactive Adaptive Visual Approaches in High-Quality Health Information, together with the Medical University of Graz and the University of Graz.
  url
• (2019 – 2022) CrossSAVE-CH, Project Assistant.
  FWF Project Crossmodal Search and Visual Exploration of 3D Cultural Heritage Objects, together with University of Graz and University of Chile.
  url

Invited Talks

• (2025) Invited talk to the VUES on Spatial Biology (Visualization and User Experience Seminar) at Harvard Medical School, Boston, "Droplets: A Marker Design for visually enhancing Local Cluster Association".
  slides
• (2023) Invited talk to the 4th Annual Workshop on Analysen von digitalen Daten musealer Objekte at Karl-Franzens-Universität, Graz, "Computerbasierte Ornamentklassifizierung in der geometrischen Vasenmalerei".
• (2022) Invited talk to the 3D-Erfassung archäologischer Objekte in den eHumanities (Seminar) at Martin-Luther-Universität, Halle-Wittenberg, "Selected Topics of the CrossSAVE-CH Project".
  slides
• (2021) Invited talk to the 3rd Annual Workshop on Analysen von digitalen Daten musealer Objekte at Karl-Franzens-Universität, Graz, "Bildbasierte Suche in Kulturgutobjekten und Visuelle Exploration mit Linked Views".
• (2019) Invited talk to the 2nd Annual Workshop on Neue Analysen von digitalen Daten musealer Objekte at Karl-Franzens-Universität, Graz, "Crossmodale Suche und visuelle Exploration von digitalen Kulturgutobjekten".

Reviewing Activities

• (2026) Springer Nature, Journal on Computing and Cultural Heritage
• (2026) ACM, Workshop on Intelligent & Interactive Health User Interfaces (HealthIUI), as part of the Program Committee.
• (2025/26) Springer Nature, Humanities & Social Sciences Communications
• (2025) Springer Nature, npj Heritage Science.
• (2025) International Conference on Computer Technology and Information Science (CTIS).
• (2024) Journal of Cloud Computing.
• (2024) Conference on Theory and Practice of Digital Libraries (TPDL), as part of the Program Committee.
• (2024/25) International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision (WSCG).
• (2024/25) Springer Nature, Pattern Analysis and Applications (PAA).
• (2023) it - Information Technology.