CIPA 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
performances and the user interface and to make it suitable for 
a productive context. 
The main developments of the software that concern the 
adaptation of the program to the quality of the data that have 
to be processed, the development of a routine set to help in the 
production, the adoption of optimised solutions to automate the 
process and the setting up of the user interface in Windows are 
here described. 
2. GENERATION OF A DDEM FROM A 3D MAP 
It is by now known [Boccardo et al., 2001] that two series of 
initial data are necessary to produce a true digital orthophoto: 
maps, whenever they already exist. It should be considered that 
this cartography is increasingly available in most of the towns, 
both as a cartographic base for urban planning and as a 
geometric base for local GIS. A 3D digital cartography 
describes the territory and buildings in planimetry and heights 
and therefore contains all the information that is necessary to 
generate the corresponding DDEM: 
• the natural ground surface is described through spot 
heights and contour lines; 
• artificial objects are represented through vertices known 
in the 3 co-ordinates (roads, bridges, and railways are 
described by polylines whose vertices are known in XYZ); 
• a set of digital images with known internal and external 
orientation parameters (obtained through bundle block 
adjustment or through direct methods based on GPS/INS 
integrated sensors) so as to guarantee the most complete 
photographic coverage of the territory as possible; 
• the correct description of the surfaces that can be 
obtained, alternatively, through a traditional DEM, 
complete with break-lines, a digital surface model (DSM) 
composed of surface geometric primitives or a dense DEM 
(DDEM): 
• buildings are described as distinct volumes of equal 
height, on whose inside a spot height (“centroid”) is 
associated. In this way, buildings can resemble to solid 
shapes (whose base is the boundary of the building) 
extruded out of the terrain up to the height of the 
associated centroid. 
An example of 3D cartographic elements is given in figure 1 
[Spalla, 2002] 
Figure 2. Some of the user interface windows 
2.1. The GeneDDEM software 
Figure 1. An example of 3D digital cartography 
This latter is often the easiest and cheapest solution to operate. 
It in fact does not require heavy restitution or editing 
operations, it does not use sophisticated software based on the 
management of complex relational and logical databases, and it 
can easily be acquired using modem instruments (laser 
scanners) or, in a cheaper way, using interpolation from 3D 
The GENEDDEM software, which has been developed in 
Visual FORTRAN language, uses the information that derives 
from a digital map to generate a dense DEM of the territory. 
The input data that are necessary are those that are found (or 
that have to be integrated) in a 3D digital map in DXF format, 
with the description of the geometry (in which all the areas are 
described by closed 3D polylines) and a list of the codes 
inherent to spot heights, contour lines, various types of