DOCUMENTATION AND ANALYSIS OF CULTURAL HERITAGE BY
PHOTOGRAMETRIC METHODS AND GIS: A CASE STUDY
G. Toz, Z. Duran
ITU, Civil Engineering Faculty, 80626 Maslak Istanbul, Turkey — (tozg, duranza)@itu.edu.tr
DS,
Commission V, WG V/4
KEY WORDS: Photogrammetry, Cultural Heritage, GIS, Visualization, Internet/Web, Virtual Reality
ABSTRACT:
Turkey is one of the rare countries with a rich cultural heritage. We have been left with a historic heritage covering the centuries
from pre-historic to modern times, which have left the marks of their civilizations on the lands of Anatolia. Therefore these riches
should be preserved and left to the next generations with the care such treasures deserve. We have to be aware of the responsibility
of leaving these treasures to the next generations as well as displaying them to the tourists. The saving methods of these treasures are
supported by modern technology. Using these methods enables us to increase the efficiency and impact of the saving process. Using
the advanced technologies in the disciplines other than architecture and by cooperation among the different fields, the future of
cultural heritage can be guaranteed in order to save the historical objects and areas. It is necessary to organize the plans and works
covering the necessary technical documents of the objects and lands to preserve these objects and lands. With the help of these
documents, it will be possible to reach the desired information for the works carried on these objects and lands. The information
system generated by the use of digital photogrammetry and Geographical Information System together will enable any person
interested in saving the cultural heritage to reach the necessary data. As mentioned above, integration of photogrammetry and GIS
leads to the efficient use of data, analysis and presentation opportunities, which are very important for saving the cultural heritage.
The aim of this study is to use this technology for the photogrammetric documentation of the cultural heritage and to enable the use
of the documentation by using GIS.
1. INTRODUCTION
Architecture is a substantial part of our cultural heritage. But
whereas other elements of our cultural heritage may be
protected by putting them behind a glass in a museum,
architectural monuments are widely used and endangered by
long term influences like traffic or air pollution or destructive
events causing heavy damage like earthquakes, fire or war etc.
But by all means when monuments are seriously damaged, or
completely destroyed, the amount and quality of any surviving
documentation becomes highly important.
Therefore it is necessary to document the actual state of the
architectural monuments in a manner, which opens the
opportunity to detect continuous damage by change detection
techniques and to restore the monument in case of heavy
damage. Before starting to acquire new data on the monument
already existing data sources have to be obtained, e.g. existing
plans of previous restorations, ancient pictures or
documentation's of architectural research projects.
The 3D reconstruction of buildings has been an active research
topic in Computer Vision as well as in Digital Photogrammetry
in recent years. Three-dimensional building models are
increasingly necessary for urban planning, tourism, etc. (Suveg
and Vosselman, 2000).
Three-dimensional photo-models help us to understand spatial
objects, even if they are not accessible for us. Using photo-
models from existing objects can make it easier for us to
understand complex spatial structures. With the help of
methods coming from virtual reality we can link additional
information in the form of text or sound sequences to our photo-
models. An architect, for example, can generate an interactive
three-dimensional information system based on a photo-model,
which describes and visualizes an important building (Dorffner
and Forkert, 1998).
Visualization efforts in Photogrammetry do not have a long
history. In the beginning of 90's the first photogrammetric
attempts were mainly focused on the use of CAD software and
the generic visualization tools they had to offer. Most of the
research efforts at that time were concentrated to automating
the data acquisition and processing through Digital
Photogrammetry concepts, thus little attention was paid on how
to add value to the data.
2. TEXTURE MAPPING AND VISUALIZATION
A three-dimensional photo-model is an object model where the
texture information is taken from photographs or other optically
working recording systems. It consists of two parts. One part is
the three-dimensional object model in which the shape of the
object surface is stored. Adjoining surface patches
approximates the object itself. The second part is the photo-
texture, which is transformed to the patches (Dorffner and
Forkert, 1998).
To visualize the derived model the photogrammetric data are
converted to VRML Virtual Reality Modeling Language).
VRML is a format for 3D data with features like hierarchical
transformations, light sources, viewpoints, geometry,
animation, fog, mate-rial properties and texture mapping (Carey
and Bell, 1997). VRML is an open format that has become
popular because of its suitability for publishing 3D data on the
World Wide Web. For this reason there is a lot of software
available that can handle VRML. This software allows a user-
friendly interactive examination and visualization of the data.
The conversion to VRML is fully automatic and consists of two
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