STEREOSCOPIC IMAGE PROCESSING USING A DIGITAL PHOTOGRAMMETRIC SYSTEM 
Nobuhiko Mori : Faculty of Information Science, Osaka Institute of Technology, Japan 
Shunji Murai : Institute of Industrial Science, University of Tokyo, Japan 
Commission I , X Working Group IWG I / Tl 
KEY WORDS: DEM/DTM, Matching, Accuracy, Resources, Analysis, Digital Photogrammetry Systems, Stereoscopic 
Image Processing, Three— dimensional Display. 
ABSTRACT: 
Stereoscopic image processing software has been developed on a digital photogrammetric system, and some 
experimental applications with this system have been carried out. 
The main processor of the digital photogrammetric system is a personal computer (PC) and has a special 
three— dimensional (3D) display module which can display stereoscopic drawings together with stereoscopic images. By 
using this 3D display module, the positions of stereo conjugate points can be passed to the computer before stereo 
matching, and the errors in stereo matching can be corrected afterward. 
Some general- purpose stereoscopic image— processing programs have been developed on the digital photogrammetric 
system. Because updated DEM can be extracted easily by the system, orthoimages of any place can be changed to 
stereoscopic images of any B/H ratio freely, and be analyzed on the 3D display module by observing the stereoscopic 
models of the stereoscopic images on it. 
Application experiments have already been carried out in some fields, such as route selection, earth resource 
exploration, etc. In the field of route selection for microwave communication, stereoscopic images overlaid with other 
information are very useful. The most suitable route can be selected by considering various kinds of conditions. In the 
field of earth resource exploration, the B/H ratio of stereoscopic images is very important. The changes in extractive 
lineaments are sensitive to the B/H ratio. It seems that this new kind of system has high application potential in many 
fields. 
functions have also been developed to extract precise 
DEMS and to analyze stereoscopic images effectively. 
1. INTRODUCTION 
Topographic information is very important in some 
application fields, and a stereoscopic image processing 
system having a 3D display is very useful in these fields. 2. 
However, there are few such systems with sufficient 
stereoscopic image processing programs. One big 
problem with this kind of system is that it is very hard to 
get appropriate DEMs for each application. The DEM is 
DEVELOPMENT OF A DIGITAL 
PHOTOGRAMMETRIC SYSTEM 
2.1 Hardware for the digital photogrammetric system 
  
used to produce stereoscopic images from an orthoimage. 
In order to get appropriate DEMs, a digital 
photogrammetric system is also necessary. Another 
problem in this digital photogrammetric system, however, 
is that, the accuracy of the DEM extracted by a digital 
photogrammetric system is not good. Generally speaking, 
the errors in stereo matching are a very serious problem 
for automatic DEM extraction with a computer, because it 
is impossible to get rid of such errors completely by 
present computer techniques. Many methods have 
already been proposed, but they all need to be improved. 
It seems that the best way is to get human help at 
appropriate stages. In order to get human help, a 
man- machine interface 1s necessary. 
In this research, stereoscopic image processing software 
has been developed on a PC-based digital 
photogrammetric system to get appropriate DEMs freely 
for each application, and special man—machine interface 
266 
In this work, a digital photogrammetric system was 
developed first, then stereoscopic image processing 
software was developed on the system, and then some 
application experiments were carried out using both of 
them. Because there was a paper written about the digital 
photogrammetric system already (Mori, 1992), the 
explanation about the system will be made briefly here. 
The main processor of the digital photogrammetric 
system is a PC made by NEC, which has a special 3D 
display module. The components of the system are a PC, 
floppy disk drives, magnetic disk drives, a mouse, three 
additional boards and liquid crystal shutter glasses. The 
liquid crystal shutter glasses are parts of the 3D display 
module. 
The 3D display module can display stereoscopic drawings 
together with stereoscopic images. Stereoscopic images 
are memorized in two frame memories. Stereoscopic 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996 
  
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