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Title
International cooperation and technology transfer
Author
Mussio, Luigi

320
4. CONCLUSIONS
Figure 5
- Test Control
Points
1
1,55
27,06
1,50
27,09
0,05
-0,03
2
1,57
25,17
1,53
25,15
0,04
0,02
3
1,57
24,72
1,55
24,71
0,02
0,01
4
0,47
27,48
0,44
27,50
0,03
-0,02
5
3,00
24,00
3,00
23,97
0,00
0,03
6
3,02
21,14
3,03
21,15
-0,01
-0,01
7
3,02
19,99
3,04
19,97
-0,02
0,02
8
3,04
17,07
3,05
17,06
-0,01
0,01
9
4,17
27,08
4,19
27,08
-0,02
0,00
10
7,44
27,10
7,44
27,10
0,00
0,00
11
10,77
27,16
10,76
27,17
0,01
-0,01
12
13,66
27,19
13,71
27,17
-0,05
0,02
13
17,59
27,19
17,63
27,19
-0,04
0,00
14
21,08
27,21
21,08
27,21
0,00
0,00
16
6,27
24,00
6,24
24,01
0,03
-0,01
17
8,40
24,04
8,37
24,05
0,03
-0,01
18
9,58
24,03
9,54
24,03
0,04
0,00
19
11,69
24,10
11,71
24,07
-0,02
0,03
20
12,79
24,12
12,83
24,11
-0,04
0,01
21
14,93
24,10
14,94
24,10
-0,01
0,00
22
16,40
24,11
16,39
24,11
0,01
0,00
23
19,92
24,09
19,93
24,07
-0,01
0,02
27
8,43
21,19
8,41
21,19
0,02
0,00
28
9,56
21,19
9,55
21,20
0,01
-0,01
31
8,45
20,02
8,45
20,00
0,00
0,02
32
9,60
20,02
9,59
20,01
0,01
0,01
33
11,75
20,08
11,75
20,07
0,00
0,01
38
8,45
17,10
8,47
17,09
-0,02
0,01
39
9,58
17,11
9,60
17,09
-0,02
0,03
0,02
0,02
Table 6 - Comparison between Object Test Control Points
Coordinates and Image Test Control Points Coordinates.
reproduce millions of colours.
The ground control points and the test control points were
surveyed by prof. B. Villa, prof. P. Marescalchi, arch. G.
Scaletta, ing. F. Coppola and by the author, within the con
text of a survey of the entire structure, “Conservatorio
dell’Annunziata.”
The ground control points were used in a number of six for
the first image, a number of seven for the second image,
a number of five for the third and fourth images. The soft
ware automatically achieved the rectification and the
mosaic of the four images (figure 4). Then, a metric con
trol was done on the rectified images by collimating 28
image points on the monitor and by comparing them with
the surveyed points (figure 5). The greatest error consti
tuted ±0,05 m in x and ±0,03 m in y, and the mean error
constituted ±0,03 m in x and ±0,02 m in y (table 6).
The image of the facade was printed at a scale of 1:100,
with a resolution of 300 ppi.
The described method permitted the acquisition of digital
images from a videorecording. These images are suitable
for rectification. There are three major advantages in
applying this method. First, it is an fast and easy method
of taking images because it is possible to later choose the
frames for rectification from the videorecording and a suit
able overlap. Second, economy and availability of the sys
tem for many users because the method can be carried
out using a personal computer with no extra hardware;
third, the possibility of using a more complete document
than a still photo, because a film contains animated video
and audio information.
On the contrary, the limitations of the method stem pri
marily from the problem of captured, low-resolution
images, and the subsequent loss of detailed information.
As a result, more images have to be used and with them
a mosaic has to be made. Presently, we do not have infor
mation about the internal orientation of the videocamera
and possible film deformations, both of which restrict the
use of such images for expeditious surveys.
Moreover, we have to consider that, in the present experi
ment, was used the cheaper and low-quality format of
video recording (VHS). Therefore the quality of the
obtained images could have been higher if the shooting
had been made using a professional format, such as
Betacam, or better digital video.
The use of a digital video camera could solve the problem
of captured, low-resolution images. In this case, the video
transformation into a digital format would be eliminated
and the resolution of the captured images would be high
er. The resolution depends on the size of the CCD sensor.
Nowadays, digital videocameras have generally a CCD
sensor of about 470.000 pixels, but they can also have a
sensor with an enhanced resolution, for example of about
810.000 pixels. This produces a resolution image higher
than the resolution of images captured by analogical
video. It is reasonable to think that, in the future, the reso
lution could increase, and inexpensive videocameras with
an higher resolution will be available. In this case, digital
shooting would provide a good quality image and could
supply the above advantages.
The second phase of research, then, will include an exper
iment using a digital video camera. This experiment will be
carried out on the same facade, the results of which will be
compared with those of the analogical camera.
BIBLIOGRAPHY
Barbash I., Taylor L., Cross-cultural filmaking, University
of California Press, Los Angeles 1997
Filosto R., II conservatorio della SS. Annunziata nel piano
di Casa Professa a Palermo. Nuovo documento sull’attiv
ità edilizia nella prima metà del XVII secolo. Collana di
studi dell’Istituto di Disegno della Facoltà di Ingegneria,
n. 4, 1966. Ristampa, Ila palma, Palermo 1976.
“Media Suite Pro User’s Guide”, Avid technology
Inc. 1994