DPA-WIN - A PC BASED DIGITAL PHOTOGRAMMETRIC STATION
FOR FAST AND FLEXIBLE ON-SITE MEASUREMENT
Carl-Thomas Schneider
AICON-Industrial Photogrammetry and Image Processing
Bültenweg 23
D-38106 Braunschweig
Tel.: ++49 / 531 / 34 45 01
Fax: ++49 / 531 / 34 45 04
KEY WORDS: Industry, Metrology, Targets, Vision, Inspection, Quality Control Systems
ABSTRACT
The request for a powerful but relatively inexpensive measurement system for a great variety of applications in close
range photogrammetry has led to the development of the PC based Digital Photogrammetric Station DPA-WIN. Major
charateristics are the modular concept of the image processing and object reconstruction software and the user friendly
handling of the DPA-WIN. Different digital imaging devices such as CCD cameras, still video cameras, and scanners
can be used as data sources.
For industrial applications the DPA-WIN is offered with still video cameras as the Kodak DCS 420 or 460 or the Rollei
Chippack as a mobile, flexible, and precise photogrammetric system for industrial measurement tasks. This paper
combines some recent developments and results achieved from application examples in industrial photogrammetry
and test measurements for verification of accuracy at the PTB (German federal office for calibration and metrology) in
order to illustrate performance and practicability of the DPA-WIN. Special emphasis is laid on additional tools for easy
data interpretation and interfaces to CAD and quality management systems.
1. INTRODUCTION
A digital photogrammetric station can be regarded as a
system for computerized production of object data from
digital imagery. The three major fields of
photogrammetric activity - aerial photogrammetry,
remote sensing and close range photogrammetry -
produce different demands and tasks to be solved.
Design, functionality, and performance of a digital
photogrammetric station have to refer to a number of
object specific and user defined requirements in order to
be applied in the daily practice of photogrammetry. In
close range photogrammetry, digital imaging techniques
are promising, e.g. in industry, medicine and
architecture.
Digital image data can be acquired directly by means of
various types of digital cameras with sensors of different
sizes. On the other hand, analogue film-based
photographs are converted into a pixel array using
desktop scanners, special purpose photogrammetric
scanners or repro scanners, respectively. The retrieved
pixel data have to be processed by software implemented
in a PC or workstation. Nowadays, different softcopy
systems are available on the market or they are in an
experimental stage in research institutions. Digital
measurement systems especially designed for close
range photogrammetry applications have been realized
(Beyer, et al. 1995, Brown, Dold, 1995, Fraser, Shortis
1994).
To meet user expectations as mobility, easy handling and
low cost, digital systems should consist of inexpensive
hardware and user friendly software tools. In previous
publications design and realization of the Digital
Photogrammetric Station DPA-WIN as a PC based
530
measurement system for close range photogrammetry
has been described (Peipe, Schneider, Sinnreich 1993).
Major characteristics are a modular software concept
with a variety of image processing and measurement
tools for 2-D and 3-D object reconstruction and a user
friendly handling of the system. Digital data from a wide
range of image sources can be imported.
Special features of the system are the use of coded
targets for fully automated image measurements,
automated orientation procedures, simultaneous camera
calibration, threedimensional measurement of points,
polylines and geometric elements in the oriented images
and graphic representation and postprocessing of
measurement results. Interfaces to CAD systems and
tools for quality assurance allow an easy interpretation
and further postprocessing of the results and the
integration of the system into quality management
systems.
By the mobile and flexible image acquisition with free
choice of image stations the DPA-WIN is especially
designed for cost reducing on-site measurements for
production and production facility control, quality
assurance, research and development.
2. SYSTEM CONFIGURATION
2.1 Hardware components
For the industrial applications described, the DPA-WIN
consists of a portable laptop with Pentium processor, a
Kodak DCS 460 still video camera and software
packages for image processing, image measurement and
data management.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996
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