Soon, both tourists and Dresden inhabitants are to dive into the past.
A small movement – and the time travel starts. All of a sudden the Dresden square Neumarkt changes its view. The church Frauenkirche’s light façade changes to dark and old. Looking left towards Johanneum, Jüdenhof, Dinglingerhaus – the colours fade away, everything turns to black and white, and different somehow.
The buildings present a reality long gone. A state of 100 years ago. Soon everybody standing on Neumarkt can see this. All they have to do is holding a smartphone in front of their eyes. Dresden scientists are working on a project intending to bring the history of Dresden alive.
For now, it is a test version. Sander Münster is turning around, holding a tablet. This device contains the functionality that tourists and Dresden inhabitants are to use in a few years’ time. While he is moving, the images of Neumarkt are changing on the small screen in his hands. Reality is overlaid by the past. History is moving in front of the newly built houses in the centre of Dresden. It becomes obvious what this place looked like before war destroyed it all.
This is made possible by Augmented Reality. This technology adds an aspect to reality, explains Münster. The postdoctoral scientist has been heading the department Media Design and Production at TU Dresden’s Media Center since 2012. Three years ago he started leading the project whose intention it is to regard Dresden’s history from different viewpoints. To reach this, Münster and his colleagues are diving into the past. Around 30,000 photographs from Deutsche Fotothek are at their disposal. These historical images serve not just one but two applications that do not exist yet.
The original idea is simple: How can urban history be conveyed intuitively? This is not just an opportunity for tourists, but also a tool for scientists, says the project leader. Kristina Friedrichs, who is the expert in architectural history within the project, regards the many images of historic Dresden very closely. She is interested in these questions: How did the photographers capture the buildings? From which point of views? And how did they influence the image of Dresden we have in our heads, and which has been revived by the reconstruction work around the Frauenkirche?
Those searching for historical city images use keywords: Frauenkirche, Zwinger, Semperoper. We were looking for a way to make it possible to move straight to the desired place, explains Münster. A computer Dresden city model as also used by the administration forms the basis. The buildings are roughly shaped. Details are visible only through added photos. This is what Jonas Bruschke is responsible for. He covers the computer model with information from the images, thus giving the buildings a texture. Bruschke shows how this is to work later.
The monitor shows the 3D model of the Zwinger, which still appears grey. Small dots around the model show which viewpoints photos are available for. As Bruschke clicks on one, the position changes to the position of the photographer immediately and the Zwinger is draped in the contents of the image. Another click makes another change, and Zwinger shows more historical cover. This opens up completely new research opportunities, explains Bruschke, who works together with computer scientists from HTW Dresden.
Until 2020, this 4D city model will be created at the computer. For this, the scientists are not only including spatial but also temporal information. It will be possible to see later how a building has changed over time. At the moment, the researchers restrict their work to the historical old town of Dresden. If the technology should work at the end of the project, the work radius could be expanded, says Münster. The technical solution was not simple. Earlier algorithms had difficulties to filter the necessary information from the historical photo material. Others have already become aware of the know-how of the Dresden team. The city of Venice has shown interest in a 4D model such as the Dresden example. And the researchers are also talking to the city of Amsterdam.
At the university of Würzburg, Florian Niebling is working towards the application for tourists. He has worked in Dresden for a few years, and is now also part of the project, which is supported by the Bundesforschungsministerium with 2 million Euros. His work is on a prototype of the technology that is supposed to make the Augmented Reality of Dresden’s old town possible. For this, the images linked to the 3D model need to be linked with real places. So the observer will have the correct images displayed on their phone according to their position. In addition, information about the buildings and possibly links to websites might be shown at a later stage. The requirements are a fast smartphone, a stable internet connection and appropriate lighting conditions.
By the end of the project most of these features are planned to be available to the public. A fully functional mobile app for everybody will still not be available then, however, moderates Münster. He hopes for a secondary project, though, whose task will be just that. So that everybody will soon be able to use their smartphones for time travels.