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LASERSCANNING AND PHOTOGRAMMETRY FOR THE MODELLING OF 
THE STATUE MARC ANTON 
Ch. Briese a ’ *, N. Pfeifer b , A. Haring a 
a Institute of Photogrammetry and Remote Sensing, Vienna University of Technology, Gusshausstrasse 27-29, 
A-1040 Vienna, Austria - (cb, aharing)@ipf.tuwien.ac.at 
b Department of Geodesy, Delft University of Technology, Thijsseweg 11, 
N-2629 JA Delft, The Netherlands - n.pfeifer@citg.tudelft.nl 
KEY WORDS: Laser scanning, Close Range Photogrammetry, Heritage Conservation Research, Adjustment, 
3D Modelling, Triangulation, CAD, NURBS 
ABSTRACT: 
Photogrammetry is a well-established method for the use of heritage recording and documentation, whereas terrestrial 
laserscanning is a rather new technique for 3D object modelling. Both sensor systems have their individual advantages. 
This paper describes the combined use of both techniques for the modelling of the statue Marc Anton. This statue, 
located in the city center of Vienna, has an approximate size of 2.5m by 5m and has a height of 3m. The statue 
represents Marc Anton sitting on a chariot pulled by three lions. The aim is to determine a 3D model of the whole 
sculpture for documentation purposes (e.g.: showing differences in the used material, decomposition and offering the 
possibility of adding further information to certain parts of the statue). First, we describe our experiences during data 
capture and focus on a description of the acquired data sets. The following work can be split into two parts. The 
first part deals with the registration of the different sensor positions and the orientation of the digital photos into one 
statue co-ordinate system using hybrid adjustment techniques, whereas the second part concentrates on the 3D surface 
modelling. The surface modelling is performed with the software package GeomagicStudio. After a 3D-triangulation the 
surface is simplified using NURBS (Non-Uniform Rational B-Splines) in order to generate a CAD model. Finally, our 
experiences with the combined use of both data capture methods ancl the modelling are presented. 
1 INTRODUCTION 
For a detailed heritage recording a lot of different 
attributes have to be captured and stored to certain 
parts of the object. For this aim a sufficient accurate 
geometric representation of the object is necessary. For 
the generation of such an object model different surveying 
methods do exist. Depending on the necessary accuracy, 
the complexity of the object and other limitations (e.g. 
time for data acquisition) the most suitable measurement 
system has to be selected. After the data capturing a 
geometric representation of the object has to be defined on 
the basis of the acquired data. This object representation 
has to offer the possibility to decompose the object into 
smaller parts in order to add local object attributes. 
Photogrammetry offering - additionally to the possi 
bility of accurate 3D point or line/curve measurements - 
texture information, being very important for the purpose 
of interpretation, is a widely used technique for 3D 
object modelling. However, the measurement capabilities 
are limited by the fact that point identification is only 
possible in textured areas and that a high degree of 
automatization can not be achieved on complex surfaces. 
In contrast to photogrammetry laserscanning pro 
vides a very high point density on the object surface, 
within a more or less automatic recording procedure 
([Pfeifer and Rottensteiner, 2001]). This allows a very 
detailed surface description. Additionally laserscanning 
is independent of texture information. In the moment 
the disadvantages of this measurement method lie in 
the measurement resolution and in the fact that laser 
scanner systems do not provide high quality RGB-texture 
information. 
This paper deals with the combined use of both 
methods in order to use the individual advantages of 
"Corresponding author. 
both mentioned measuring techniques for the recording 
of the statue Marc Anton (see Fig. 1). The statue 
located in the city center of Vienna has an approximate 
size of 2.5m by 5m and has a height of 3m. The statue 
represents Marc Anton sitting on a chariot pulled by 
three lions. A fourth lion can be found on the back 
side of the statue. The data capturing is described 
in Sec. 2, whereas Sec. 3 describes the registration of 
the different data sets, including also an accuracy analysis. 
Challenging is the modelling of the detailed struc 
tured surface (cf. Sec. 4). Details with extensions less 
than 1cm can be found on the object, e.g. in the face of the 
lions or Marc Anton. From the geometrical point of view 
no parametrization over a plane or another simple surface 
(e.g. a sphere or cylinder) of the whole statue is possible. 
Furthermore, small holes (e.g. between the spokes of the 
wheels) increase the complexity of the object. Due to the 
overall complex structure occlusions cannot be avoided 
and some areas cannot be digitized without tremendous 
effort (e.g. underside of the lions bodies). To reduce the 
time for data acquisition we accepted some data gaps and 
some loss of detail. The following final section is devoted 
to the discussion of the results. 
2 DATA CAPTURING 
For the data capturing we used the digital camera Ko 
dak Professional DCS460c and the Riegl LMS-Z360 (cf. 
K , 20031) laser scanner. The camera based on a Nikon 
ses a CCD-array with 2036 x 3060 elements (6.2 mil 
lion pixels) in the image plane with a pixel size of 9/xm. 
50% of the pixels record the intensity of green radiation, 
whereas 25% of the pixels are used to store the red and the 
blue, resp. color information. With the help of an inter 
polation method digital pictures with 2036 x 3060 pixels 
are computed. To capture the object and the surrounding 
tie points we used a 28mm lens with an average distance