an example some prototypes of digital photogrammetric
workstations (DPW) have been developed in the last few
years. The characteristics and advantages of such systems
in comparison to analytical instruments can be expressed
(Ref. 1 and 2) by the following items:
- no need for high precision opto-mechanical parts
- robust measurements system
- stable image geometry
- automatic, semi-automatic or manual operation
- high degree of interactivity
- data acquisition, storage and processing in one system
- on-line and real-time capabilities
- direct 3 dimensional graphic superimposition possiblities
- possible use as data acquisition and processing instrument
in GIS
Recognizing decreasing hardware costs, the possible advan
tages of such systems for the processing of digital images
are the increase in accuracy, the high degree of automation
yielding in a faster availability of the results. A classification
of the existing systems shows the existance of 3 major
groups:
- Custom build systems, which are of great functionality
and have a high performance, but are generally very
expensive.
- Systems based on conventional image processing systems,
where image processing function may be directly used,
but which generally have a lack of openess with respect
to hard- and software.
- Modular systems, which are open with respect to the
integration of hard- and software and generally can be
considered very flexible, but which require a high effort
in developing adequate user interfaces and data manage
ment software.
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