Graffiti upset, please, provoke. However, they are also short-lived, and often exist only for several hours or days. If not documented, part of this unique cultural heritage will vanish forever. The INDIGO project tries to change this by building an online 3D platform to analyse and present graffiti scapes.
Graffiti are virtually in every urban area worldwide. Some consider the colourful (and mostly illegal) paintings vandalism, others consider them art. Some feel provoked while others appreciate their existence. No matter what we think about graffiti, they are part of our cultural heritage and deserve to be treated as such.
One of the largest and most vibrant graffiti scapes worldwide is the Donaukanal in Vienna, Austria. A new research project aims to systematically document and analyse the graffiti there by 3D modelling techniques for the long-term preservation of this unique form of cultural heritage.
Who cares about graffiti?
It is impossible to avoid them when strolling around a town: small scribblings on bridge pillars, trash cans, or huge paintings on house facades. Opinions on graffiti are diverging. While some love them and see the artistic value and a colourful variation between the grey city’s concrete, others would like to have them removed immediately. Graffiti are polarising, and that is what makes their documentation so interesting– one would think, at least. In fact, hardly any documentation exists of graffiti that pop up in our urban environments. Most graffiti vanish undocumented and are lost forever.
Graffiti hotspot Donaukanal
One of the largest and most famous graffiti hotspots worldwide is the Donauakanal (Eng.: Danube Channel) in Vienna. Located near the city centre, it is a popular recreational area for Viennese people. Since the early 1980s, Donaukanal has also become increasingly famous for graffiti spraying, which is why today there are almost no empty spots along a ca. 7 km stretch of the Donaukanal. This graffiti density also means that every time a new graffito is sprayed along the walls of Donaukanal, an existing graffito beneath is destroyed, and if not photographed, it is lost forever.
Documenting graffiti in project INDIGO
In September 2021, the graffiti research project INDIGO (INventory and DIsseminate
Graffiti along the dOnaukanal) was launched. INDIGO aims to digitally document the graffiti along Donaukanal and make them publicly available. As a part of the project, we create a 3D model in which users can take a virtual stroll along the Donaukanal, view, and analyse the graffiti that were sprayed there in the past few weeks, months and years.
The point clouds’ role in studying graffiti
To achieve a full 3D model of the graffiti-covered surfaces along the Donaukanal, the INDIGO team took ca. 27,000 images of the Donaukanal from which a 3D point cloud (of about 14 Million points) was derived. The technique behind this is “Photogrammetry“. It relies on the fact that a point (for example, a corner point of a wall) that is visible in two or more images can be three-dimensionally reconstructed. Specifically, here we use “Structure from Motion” (SfM), which also incorporates camera motion information to construct the 3D point cloud faster. This point cloud serves as the basis for a final, continuous 3D model (represented by a mesh), something the researchers are still working on.
An interactive point cloud of the Donaukanal graffiti. Navigate your way within this initial (and non-cleaned) point cloud created from tie points found in the images.
Find out more!
If you want to find out more about the graffiti at Donaukanal and how INDIGO digitally preserves them and makes them available to the public, check out our website, follow us on Instagram, or take a quick look at our Twitter feed:
INDIGO is funded by the Heritage Science Austria programme of the Austrian Academy of Sciences (ÖAW)
Technical Details
Acquisition by 27000 images along the Donauknal (approx. 14 km in total)
- 14 Million Points,
- ca. 80% overlap between the images
- 3D georeferenced (EPSG: 31256)
- About 560 Control Points were measured at 21 clusters along the Donaukanal
- Accuracy: ca. 2cm
Participants in Research
- Research Group Photogrammetry, TU Wien
- Norbert Pfeifer
- Benjamin Wild
- Ludwig Boltzmann Institut für Archäologische Prospektion und Virtuelle Archäologie
- Geert Verhoeven
- and many more
Further Reading
This post is based on the scientific paper(s)
Some images were taken from the paper Verhoeven, G., Wild, B., Schlegel, J., Wieser, M., Pfeifer, N., Wogrin, S., Eysn, L., Carloni, M., Koschiček-Krombholz, B., Molada-Tebar, A., Otepka-Schremmer, J., Ressl, C., Trognitz, M., Watzinger, A., 2022. Project INDIGO – document, disseminate & analyse a graffiti-scape. Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci. XLVI-2/W1-2022, 513–520. DOI: 10.5194/isprs-archives-XLVI-2-W1-2022-513-2022
Graffiti upset, please, provoke. However, they are also short-lived, and often exist only for several hours or days. If not documented, part of this unique cultural heritage will vanish forever. The INDIGO project tries to change this by building an online 3D platform to analyse and present graffiti scapes.
Graffiti are virtually in every urban area worldwide. Some consider the colourful (and mostly illegal) paintings vandalism, others consider them art. Some feel provoked while others appreciate their existence. No matter what we think about graffiti, they are part of our cultural heritage and deserve to be treated as such.
One of the largest and most vibrant graffiti scapes worldwide is the Donaukanal in Vienna, Austria. A new research project aims to systematically document and analyse the graffiti there by 3D modelling techniques for the long-term preservation of this unique form of cultural heritage.
Who cares about graffiti?
It is impossible to avoid them when strolling around a town: small scribblings on bridge pillars, trash cans, or huge paintings on house facades. Opinions on graffiti are diverging. While some love them and see the artistic value and a colourful variation between the grey city’s concrete, others would like to have them removed immediately. Graffiti are polarising, and that is what makes their documentation so interesting– one would think, at least. In fact, hardly any documentation exists of graffiti that pop up in our urban environments. Most graffiti vanish undocumented and are lost forever.
Graffiti hotspot Donaukanal
One of the largest and most famous graffiti hotspots worldwide is the Donauakanal (Eng.: Danube Channel) in Vienna. Located near the city centre, it is a popular recreational area for Viennese people. Since the early 1980s, Donaukanal has also become increasingly famous for graffiti spraying, which is why today there are almost no empty spots along a ca. 7 km stretch of the Donaukanal. This graffiti density also means that every time a new graffito is sprayed along the walls of Donaukanal, an existing graffito beneath is destroyed, and if not photographed, it is lost forever.
Documenting graffiti in project INDIGO
In September 2021, the graffiti research project INDIGO (INventory and DIsseminate
Graffiti along the dOnaukanal) was launched. INDIGO aims to digitally document the graffiti along Donaukanal and make them publicly available. As a part of the project, we create a 3D model in which users can take a virtual stroll along the Donaukanal, view, and analyse the graffiti that were sprayed there in the past few weeks, months and years.
The point clouds’ role in studying graffiti
To achieve a full 3D model of the graffiti-covered surfaces along the Donaukanal, the INDIGO team took ca. 27,000 images of the Donaukanal from which a 3D point cloud (of about 14 Million points) was derived. The technique behind this is “Photogrammetry“. It relies on the fact that a point (for example, a corner point of a wall) that is visible in two or more images can be three-dimensionally reconstructed. Specifically, here we use “Structure from Motion” (SfM), which also incorporates camera motion information to construct the 3D point cloud faster. This point cloud serves as the basis for a final, continuous 3D model (represented by a mesh), something the researchers are still working on.
An interactive point cloud of the Donaukanal graffiti. Navigate your way within this initial (and non-cleaned) point cloud created from tie points found in the images.
Find out more!
If you want to find out more about the graffiti at Donaukanal and how INDIGO digitally preserves them and makes them available to the public, check out our website, follow us on Instagram, or take a quick look at our Twitter feed:
INDIGO is funded by the Heritage Science Austria programme of the Austrian Academy of Sciences (ÖAW)
Technical Details
Acquisition by 27000 images along the Donauknal (approx. 14 km in total)
- 14 Million Points,
- ca. 80% overlap between the images
- 3D georeferenced (EPSG: 31256)
- About 560 Control Points were measured at 21 clusters along the Donaukanal
- Accuracy: ca. 2cm
Participants in Research
- Research Group Photogrammetry, TU Wien
- Norbert Pfeifer
- Benjamin Wild
- Ludwig Boltzmann Institut für Archäologische Prospektion und Virtuelle Archäologie
- Geert Verhoeven
- and many more
Further Reading
This post is based on the scientific paper(s)
Some images were taken from the paper Verhoeven, G., Wild, B., Schlegel, J., Wieser, M., Pfeifer, N., Wogrin, S., Eysn, L., Carloni, M., Koschiček-Krombholz, B., Molada-Tebar, A., Otepka-Schremmer, J., Ressl, C., Trognitz, M., Watzinger, A., 2022. Project INDIGO – document, disseminate & analyse a graffiti-scape. Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci. XLVI-2/W1-2022, 513–520. DOI: 10.5194/isprs-archives-XLVI-2-W1-2022-513-2022
