8 cm), by 5 couples
on of stereoscopics
of the plant and the
carried out, using a
n photograms) with
n focal length and
Le
gram
‘ilm Camera (n. 8
ulon 65mm,
camera (7mm focal
ition allowed by the
s for each one.
| cameras have been
grammetric Scanner
>s of about 200 MB
era
pic models through
by SISCAM
| a suitable stereo
ith procedures of
btained the Digital
h the automatic
of the Stereometric
ain a grid of 5x5cm
s a very interesting
laboration.
)XF files in order to
the cloud of points
of image in digital
canner (Fig. n.4).
Figure 3: Photogrammetric cloud of points
Figure 4 : Laser Scanner cloud of points
These different files have been treated in GIS enviroment
(Arcview 3.1 with 3D Analyst ) to obtain three-dimensional
models ( DEM) with the typical instruments of 3D analysis,
like shows in the following images : results of
photogrammetric survey (Fig. n. 5) and results of Laser Scanner
(Fig. n. 6).
Later we have compared the results of the two techniques of
DEM production by pointing out the qualitative characteristics
and verifying the usability in order to extract metric
informations by digital representation of the architectonic
building.
In spite of remarkable problems concerning the corrected
definition of suitable breaklines and difficult extraction, the first
DEM by photogrammetric survey with 5 x 5 cm grid of
acquisition, gives a very interesting result.
Figure 5: Photogrammetric DEM
The second DEM produces a more detailed model than the
previous one, thanks to the denser grid allowed by the Laser
scannning methodology, and presents less accuracy in the part
where the Scanner Laser has produced a little number of
extracted points.
This problem will be resolved when all the four model by Laser
Scanner will be linked in only one reference local system that
involves all the Church.
Figure 6: Laser Scanner DEM
3D Model
An interesting experience was the realization of a three-
dimensional model of the Church starting from the digital
images of the EOS Systems Inc. Photomodeler software, which
let us realize the 3D model of the building using at less two
digital photos.
The result consists of a 3D model easily navigable in the three
dimensions even with a normal browser internet ( Internet
Explorer ...) equipped with a plug-in for the VRML.
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