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A NEW PERSPECTIVE FOR THE VISUALIZATION OF CARTOGRAPHIC DATA 
V. Tsioukas!, K. Papadopoulos®, M. Daniil', E. Daniil^ 
"The Aristotle University of Thessaloniki, Greece, Dept. of Cadastre, Photogrammetry and Cartography, 
National Center for Maps and Cartographic Heritage, Greece 
Email : tsioukas @egnatia.ee.auth.gr, kostas @maplibrary.gr 
Commission V, Working Group V/6 
KEY WORDS: 3D Map, visualization 
ABSTRACT: 
In a conventional map cartographic data are considered two-dimensional information that are used for navigational, educational and 
many other reasons. A conventional map is usually printed on 
paper in some certain and unchangeable scale. However a modern 
map is created using digital techniques and after it has been processed in a computer, it is printed on paper. Digital equipment 
provides many more opportunities to visualize information that is embedded on a map. 
The most important aspect that is presented in this paper is the use of the depth information (third dimension) that is usually drop out 
and is not visible on a conventional map. The visualization techni 
adopted to produce an innovative type of data: 3D map. 
1. INTRODUCTION 
Cartographic data, namely the maps have been used for various 
reasons during the years of their use. Their main usage was for 
navigational reasons especially for travellers. However the 
maps are not only constructed as a tool for navigation through 
the seas and the land. A map plays also the role of an 
information bank that demonstrates the features (thematic 
information) of a region on the earth using toponyms and 
specific symbols, showing the exact location (X, Y and in some 
cases Z coordinates) of these features on it. 
Generally speaking, a map is considered to be a 2D information 
base that is produced from the orthogonal projection of the 
main features of the 3D object space on paper using a specific 
scale. These are also the main characteristics that appear when 
creating a map: 
e The rejection of the depth information of the 3D 
world on the map 
e The creation of a product that represents information 
(with various importance levels) on the map in some 
unique ant non alterable scale 
Many maps allow the presentation of 3D information of the 
mapped region using either contour lines or an image 
background containing variations of colours. This depth 
information (through contour lines or using coloured variations 
of the background image of the map) is not a standard feature 
that appears on a typical map. It has been very difficult to 
embed 3D information on paper. On the other hand, the contour 
lines do not provide an easy way to extract the 3D information 
of the mapped objects. That's why new techniques must be 
introduced to provide an easy way to demonstrate all the 
valuable information of a map using a real 3D product. 
2. COMBINATION OF CARTOGRAPHIC DATA WITH 
IMAGE DATA 
With the advent of the digital era almost 10096 of the maps are 
created using the computers’ technology. Photogrammetry 
plays a very important role in this procedure, since it supplies 
the georeferenced digital images that are finally digitised and 
they provide the map of a region of the earth’s surface. 
ques that are used to present photogrammetric products have been 
Typical photogrammetric products are the Digital Elevation 
Model (DEM) of the imaged objects and the digital orthophoto, 
which present the object space in the same way as a map. The 
post processing of the digital orthophoto can certainly lead to 
the creation of a map using CAD Software applications. For 
example, the orthophoto (raster information) can be digitised 
and supply the vector information i.e. road, rivers, etc and many 
other geophysical features of a map. 
Raster and vector information of a map can be combined using 
advanced image processing software applications such as 
CorelDraw and Adobe Illustrator. In this way a digital map of a 
region of Mt. Athos in Greece has been created as it is 
illustrated in fig.1. 
The fussed image of the raster and vector data can be used to 
drape the object’s model that has been created from the DTM 
derived from the digitization of the contour lines of a map. 
This technique has been used quite a lot lately and has given 
some very good visualization products of photogrammetric data 
and has also given virtual reality models (VRML) of the imaged 
object. 
Instead of using the ortho image for the draping of the model, 
its combination with the vector image has been used. This way 
it has been accomplished to place in their exact location the 
whole set of cartographic data (i.e. roads, rivers, etc) since they 
are placed on a surface that is an actual 3D model of the real 
object and not on a just plane surface. An innovative kind of a 
map is created that we call a 3D map. 
3. VIDEO CREATION 
Additionally to the created 3D map that is only available 
through a CAD-CAM software application a video file that 
presents a virtual fly-over on the maps data can be created. 
Many researchers have used video files to visualize 
cartographic data but not many of them have combined 
cartographic and photogrammetric products to produce an 
animation around a 3D object’s model. The final product that 
has been produced in our case consists of a sequence of images 
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