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