You are using an outdated browser that does not fully support the intranda viewer.
As a result, some pages may not be displayed correctly.

We recommend you use one of the following browsers:

Full text

Proceedings of the Symposium on Progress in Data Processing and Analysis

Digital techniques use digital images and digital processing. A
combination of both techniques is implemented in hybrid systems,
using partly analogue and partly digital images in the course of
Analytical, hybrid and digital techniques are versitile and
flexible. The corresponding systems can be easily integrated into
larger entities.
The variety of the systems' architecture, their utilities and
performances, makes a uniform overall comparative evaluation very
difficult; hence, partial evaluations seem to be more practical.
First, however, consideration is given to some significant
contextual factors that influence the technical evolution.
Accordingly, the evaluation criteria are stated, and then the common
features of each technique or system type are studied and assessed.
Evaluation of the specific features is differentiated according to
the main production lines.
Analytical and hybrid techniques have recently reached operational
maturity. The digital techniques are on the threshold of maturity
for automatic aerial triangulation and for medium and coarse terrain
relief modelling. They are also applicable to image transformations,
such as to orthophotographs. The reduced quality of digital images,
however, impairs the modelling of terrain features other than
The major potential of digital techniques is their flexibility and
ease for automation.
For a comparative study of the analytical and digital techniques and
systems, the following contextual factors seem to be most
- New developments in the basic and related fields;
- The state of the art in GI technology, especially in
- The techniques for the GI applications in users' domains.
These factors are mutually related (figure 1). In the following,
consideration is given to each.