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THREE DIMENSIONAL SURFACE RECONSTRUCTION WITH THE ZEISS
PHOTOGRAMMETRIC INDUSTRIAL MEASUREMENT SYSTEM
InduSURF Digital
Dipl.-Ing. Torsten Kludas
Carl Zeiss Jena GmbH, D-07740 Jena, Tatzendpromenade 1a, Tel./Fax: +49-3641-64-2496 / 3340
KEY WORDS: Close Range Photogrammetry, Digital Photogrammetric System, Automatic DEM Generation
ABSTRACT:
Industry requires easy-to-operate photogrammetric measuring systems featuring a high degree of automation and top
accuracy, which allow complicated industrial problems to be solved in a short time without photogrammetric know-ledge
being required.
The new InduSURF System is based on the digital image. Taken with digital sensors of a high resolution such as the
UMK-SCAN or JenSCAN, it is an essential factor for accurate and effective operation. Image measurement with the
DIAMANT program is the first step for the orientation of the image block with the bundle adjustment program BINGO.
The information thus received forms the basis of the InduSURF program performing the correlation computation for the
automatic acquisition of 3D surface information.
The paper describes the system by examples showing the system's practical application in the automotive and steel
industries, for instance.
1. INTRODUCTION
With the development of powerful, high-resolution cameras, the industrial market is becoming increasingly receptive to a
photogrammetric approach to automatic 3D coordinate measurement. In this field, digital photogrammetry offers a
genuine alternative to conventional measuring methods such as coordinate measuring machines and thus joins the
ranks of contact-free optical measuring techniques. These techniques are now challenging the conventional tactile
measuring systems with the aim of gaining a continuously increasing share of the market.
Compared with other optical or tactile measuring methods, the photogrammetric principle of digital image correlation
offers considerable benefits in the automatic digitization of surfaces for the creation of a three-dimensional data base for
CAD/CAM surface reconstruction or CAQ nominal-actual checks. A very extensive and diversified market exists for such
a system. The small amount of photogrammetric recording and plotting equipment required makes digital InduSURF
attractive for industry as a complete photogrammetric system whose mobility also permits direct plotting on site.
2. THE SYSTEM AND ITS COMPONENTS
2.1 Digital image recoding: Sensors from 768 x 512 to 15414 x 11040 pixels
The selection of the sensor for the technical performance of a project or measuring task primarily depends on the
following factors:
C) the size of the object to be measured,
QU the accuracy required by the user,
Q the recording conditions specific to the object,
a the time available for recording and plotting.
For the digitization of large objects with measuring surfaces of more than 3-4m?, the UMK-SCAN high-resolution large-
field scanner from Carl Zeiss Jena is used as a stereo system. As a result, only a minimal number of images and model
tie points is required and the plotting time is reduced, whereas the accuracy remains very high even if extensive objects
are involved. For smaller objects with critical accuracy requirements, a stereo camera system comprising JenScan
cameras from the Jena company RJM is used. In addition, still-video cameras such as KODAK DCS 420 mi or RIM
JenaCam can be used for special measuring tasks.
The computer platform for all these digital camera systems is a PC with MS-DOS operating system. The cameras are
calibrated for discrete focussing steps, this being necessary since many applications do not permit a sufficient number
of images or points to be obtained for ensuring reliable simultaneous calibration. The image grabbing software of all
sensors is dialog-oriented on the basis of MS-WINDOWS and is extremely easy to operate. Black-and-white stereo
images with a resolution of 8 bits in 256 grey levels are scanned and processed.
IASPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop "From Pixels to Sequences", Zurich, March 22-24 1995
