Urban Creativity Meets Engineering

Automated Graffiti Mapping along Vienna’s Donaukanal

  • Benjamin Wild TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria
  • Geert J. Verhoeven Ludwig Boltzmann Gesellschaft - LBI ArchPro, 1190 Vienna, Austria
  • Stefan Wogrin SprayCity, Austria
  • Martin Wieser Independent researcher
  • Camillo Ressl TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria
  • Johannes Otepka-Schremmer TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria
  • Norbert Pfeifer TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria
Keywords: AUTOGRAF, graffiti, orthophoto, photogrammetry, street art, structure from motion

Abstract

Graffiti are polarising. Some consider them vandalism, others part of our cultural heritage. If we consider graffiti to be part of our cultural heritage, we should also treat them as such. However, long-term and detailed graffiti documentation initiatives are sparse, so many of the existing archives with graffiti records are biased and incomplete. In addition, graffiti records usually suffer from decontextualisation, that is the lack of environmental information (be it spatially, temporally, but also smell and weather conditions). This means that graffiti documentation might not reflect the intended setting or meaning by the creator. INDIGO, a graffiti-centred academic project, largely overcomes the issue of decontextualisation by designing and implementing photogrammetric engineering approaches that support the ongoing documentation of an extensive graffiti-scape. The latter is situated along the Donaukanal, Vienna’s central waterway and one of the most prominent graffiti hotspots worldwide. One innovation developed in the framework of INDIGO is a freely available Metashape add-on called AUTOGRAF. AUTOGRAF employs photogrammetric computer vision techniques to automatically create ortophotographs from all photographed graffiti. Orthophotographs or orthophotomaps are distortion-free images, combining photographs’ visual qualities with characteristics of maps. They allow embedding the graffiti in their native, albeit virtual, 3D environment and can thus largely overcome decontextualisation.

In this contribution, we showcase the significant advantages of orthophotomaps over conventional photographs and introduce the AUTOGRAF-based workflow that allows the automated derivation of graffiti orthophotos. INDIGO will use this tailor-made tool to enable graffiti analysis in unprecedented detail by mapping and displaying graffiti in their original setting along the Donaukanal.

Author Biographies

Benjamin Wild, TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria

Benjamin Wild (°1996) is a PhD student and university assistant at the Photogrammetry unit at the Department for Geodesy and Geoinformation at Technische Universität Wien (TU Wien). He received his Master’s degree from TU Wien in Geodesy and Geoinformation in 2021. Since then, he has been part of the graffiti-centred academic project INDIGO. Before investigating photogrammetric solutions in the context of graffiti research, Benjamin was working in the same department but in the field of environmental microwave remote sensing. What connects both experiences is the interest in understanding our environment better. Be it the amazon rainforest or the graffiti along Donaukanal. Benjamin’s research output can be found at https://www.researchgate.net/profile/ Benjamin-Wild-5.

Geert J. Verhoeven, Ludwig Boltzmann Gesellschaft - LBI ArchPro, 1190 Vienna, Austria

Geert J. Verhoeven (°1978) is a senior researcher in archaeology at the LBI AchPro and is currently leading the academic graffiti project INDIGO. He received his Master’s and PhD degrees from Ghent University (Belgium) in 2002 and 2009, respectively. Since 2010, Geert has been working on many 3D modelling, remote sensing and data visualisation topics at the LBI AchPro, a research institute of which he is currently the vice director. In September 2021, Geert took a deep dive into the colourful graffiti world through project INDIGO. His research output can be found at https://www.researchgate.net/profile/Geert- Verhoeven-2.

Stefan Wogrin, SprayCity, Austria

Stefan Wogrin (°1989) is an art historian and graffiti documenter. In 2001 he founded the “Spraycity “graffiti writing archive (https://spraycity.at), which is also an online platform where 100.000 graffiti photos are accessible online. The archive is based in Vienna. He received his Bachelor of Arts in art history and European ethnology from the University of Vienna in 2017. Since 2001 Stefan is also an active graffiti writer. Furthermore, he photographs graffiti from all different public surfaces in Vienna and the entire Europe. Since 2013, Stefan has also been researching the history of graffiti in Vienna, which is his main research interest. Stefan curated several exhibitions about graffiti, and he is the editor of the “Offline Graffiti Magazine “. The research Stefan is involved in can be found at https:// spraycity.at/research.

Martin Wieser, Independent researcher

Martin Wieser (°1986) is an independent researcher in photogrammetry and remote sensing. He received his Master’s degree from the Technical University of Vienna (TU Wien, Austria) in 2012. From 2010–2019, Martin worked on many photogrammetry, 3D modelling, remote sensing and data visualisation topics at the TU Wien as a project and university assistant. Since 2016, Martin has also been developing geospatial soft- and hardware prototypes for researchers worldwide (Historic England, University of Vienna, Murdoch University Perth).

Camillo Ressl, TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria

Camillo Ressl (°1971) is a senior scientist at the Department for Geodesy and Geoinformation at Technische Universität Wien (TU Wien). He received his Master’s and PhD degrees from TU Wien in 1997 and 2003, respectively. His general research interests cover photogrammetry, laser scanning and point cloud processing. He mainly focuses on parameter estimation, error minimisation and geometric modelling. From 2004–2008 he was chair of the Commission III working group on ‘Automatic Calibration and Orientation of Optical Cameras’ of ISPRS (International Society of Photogrammetry and Remote Sensing). Camillo acts as a reviewer for many scientific journals and (co-)authored many publications, which can be found here: https://repositum.tuwien.at/cris/rp/rp04464.

Johannes Otepka-Schremmer, TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria

Johannes Otepka-Schremmer (°1975) is a senior scientist at the Department of Geodesy and Geoinformation at the TU Wien. He wrote his Master and PhD thesis at the TU Wien (Austria) and Melbourne University (Australia) about close-range photogrammetry and received the corresponding degrees in 2001 and 2004. Since 2004, he has been working on various geomatic topics, including point cloud processing, laser scanning, spatial indices, efficient processing concepts and least-squares at the TU Wien. He supports the INDIGO project with his expertise in creating, storing, and visualising 3D geodata. His publications can be found at https://pub-geo.tuwien.ac.at/publist.php?lang=2&zuname=Otepka&vorname=Johannes.

Norbert Pfeifer, TU Wien - Department of Geodesy and Geoinformation, 1040-Vienna, Austria

Norbert Pfeifer received his PhD. from TU Wien in 2002. He then worked at TU Delft, the University of Innsbruck, and the alp-S Centre for Natural Hazard Management, before taking the position of Professor of Photogrammetry at TU Wien. His research interests are laser scanning and photogrammetry, including sensors, calibration, 3D modelling and application of these models in environmental and cultural heritage sciences. List of publications: https://scholar.google.at/citations?user=-HuwYEMAAAAJ.

Published
2023-05-10
How to Cite
Wild, B., Verhoeven, G., Wogrin, S., Wieser, M., Ressl, C., Otepka-Schremmer, J., & Pfeifer, N. (2023). Urban Creativity Meets Engineering. Document | Archive | Disseminate Graffiti-Scapes, 131 - 145. https://doi.org/10.48619/indigo.v0i0.705