TOGRAPHS 
), Close Range, 
tally destroyed, is 
/ consist the most 
> of such pictures 
the building/object 
is presented. The 
, gave a 3D digital 
; a CAD package. 
egree of accuracy 
ical Archive of the 
llections, special 
s of the area of 
) resulted to the 
es, most of them 
Jllding, taken from 
ales and on dates 
ntury until the date 
| important of them 
roduced, so that 
ide 
of the area during 
30's. Only one pair 
proved useful for 
taken in 1965, at a 
of the building, in 
of the building at a 
vestern side of the 
d in 1921 
“a scale of 1:50, 
at a scale of 1:50, 
r changing the use 
Nautical Museam 
the first floor at a 
of the second floor 
ing old plans of the 
compared with the 
rtant of them are 
e upper part of the 
e facade plans 
1996 
e the windows which are shown on the upper part of the 
western side and in fact never constructed 
e the structure of the tile ceilings instead of cement-made 
ones on the eastern and western side of the building 
e the structure of a ventilator on the ceiling of the tower- 
clock, which is not shown in any one of the facades 
e certain details on the sides of the tower-clock 
e certain differences on the windows. 
Besides, no other plan of the northern side of the building 
was found. 
3. PHOTOGRAMMETRIC DATA PROCESSING 
The determination of the necessary digital data (3D 
coordinates of characteristic points) for the completion and 
the correction of the existing plans of the facades is 
accomplished. The procedure followed consists of 
e analytical processing of the stereopair of airphotos and 
e digital rectification of various planes of the facades on 
the amateur pictures. 
3.1 Analytical Processing of the airphotos 
The X, Y, Z coordinates of the main characteristic points 
of the building, which were recognisable on the stereopair 
of airphotos of 1965, such as the corners of the building in 
various hights, on the balconies, ceilings, clock etc, were 
determined. The coordinate calculation was made on an 
analytical photogrammetric instrument. For the orientation 
of the stereopair the coordinates of 5 control points were 
measured by field surveying methods with an accuracy of 
a few centimeters. These control points are clearly 
  
Figure 1. Old amateur photograph of the northeastern side of the building 
^ + 
defined, easily recognisable on the airphotos, located on 
the surrounding area of the building and belong to 
permanent structures that have remained unchanged since 
1965. The characteristic points of the building that have 
been determined by stereorestitution are 120 in total and 
their coordinates have been calculated with an accuracy of 
15-25 um on the photo scale, or of 10-15 cm on the 
ground. 
3.2 Digital Rectifications 
Digital Rectifications of all planes of each of the four sides 
of the building have been accomplished by using the 
calculated coordinates of the characteristic points and 
metric information derived from the existing plans. The 
hardware used was a standard IBM-compatible PC with 
80486 microprocessor and 8 Mb of RAM. 
For this purpose, the seven forementioned most important 
amateur photos were scanned with a 600 dpi resolution. 
Since each side of the building consists of more than five 
planes (see Fig. 2 & 6), occasionally certain sides had to 
be produced by a combination of rectified planes taken 
from more than one pictures, in order to avoid hidden parts 
or large tilts or parts of small scale. The scales of the 
scanned photos are between 1:100 and 1:300. Since a 
magnified papercopy was used the image quality of the 
analog photos was comparatively poor, so a careful 
radiometric image processing of the scanned images 
(contrast and brightness enhancement, edge detection etc) 
was made. 
In most rectification planes the determination of control 
points was impossible, because there was a difficulty in 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996