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5.2 Stereoscopic image analysis in the field of earth 
resource exploration 
As mentioned above, the B/H ratio of stereoscopic 
images is very important in the field of earth resouce 
exploration. The reason is supposed to be that very small 
changes in the shape of the earth surface are important 
and cannot be ignored. So, for effective analysis, the B/H 
ratio of stereoscopic images must be considered in the 
field. 
Photo 12 shows an application in the field of earth 
resource exploration. In this photo, broken lines are 
faults, filled dots are hot springs, and small marks like 
eyes are veins of mineral. This information was written 
on an orthoimage using the calculation program 
developed in this system and then transformed to 
stereoscopic images. The B/H ratio of these stereoscopic 
images is 0.5, which is the most suitable value in this 
area. Looking at these stereoscopic images with liquid 
crystal shutter glasses, we can get precise topographic 
information together with information in images and 
overlaid information. The man— machine interface is also 
available, which makes it possible for the operator to 
draw dots and lines on these stereoscopic images to 
indicate the results of image analysis. 
  
Photo 12 Application example in the field of earth resource exploration 
6. CONCLUSION 
Stereoscopic image processing software has been 
developed on a digital photogrammetric system. By using 
this system with stereoscopic image processing software, 
updated precise DEMs of any place can be extracted 
easily from digital stereoscopic images with the help of a 
man— machine interface of the 3D display module. 
Overlaid stereoscopic images of any B/H ratio can be 
produced from orthoimages using the DEM and the 
Stereoscopic image processing software, and effective 
analysis can be carried out in many application fields by 
using the stereoscopic model of overlaid stereoscopic 
images and the functions of the man- machine interface. 
The most significant features of this system are as follow: 
1) Because this system has a special man- machine 
interface, precise DEMs can be extracted from digital 
stereoscopic images using human inputs. 
2) Because precise DEMs can easily be obtained at any 
place, stereoscopic images of any B/H ratio can be easily 
produced from an orthoimage. 
3) Because this system has many stereoscopic image 
processing programs and a special 3D display module, 
analysis and designs using stereoscopic images can be 
carried out effectively. 
It can be said that this system has high application 
potential in many fields. 
Finally the authors would like to express their 
appreciation to the members of the Murai laboratory at 
Tokyo University, of the ERSDAC and of the NEC 
corporation for their contributions to this research. 
[ References ] 
1. M.Boulianne, P.A.Gagnon, J.P.Agnard, C.Nolette, 1990; 
Large Scale Map Revision Using a  PC- Based 
Videoplotter; ISPRS Com.4, Tsukuba, Japan, pp.273— 279 
2. N.Mori, H.Takaoka, K.Tonoike, J.Komai, S.Murai,1988; 
Investigation of the Effectiveness and Applications of 
Japanese ERS—1 Stereoscopic Images; ISPRS, Kyoto, 
Japan, Vol.27, Com.1, pp.109— 119 
3. N.Mori, S.Masuda, S.Murai, 1992; Development of a 
PC- Based Digital Photogrametric System; ISPRS, 
Washington, B2— 2, pp.319— 322 
4. N.Mori, 1995; Development of a Stereoscopic Image 
Processing Software; ACRS, Nakhon Ratchasima, 
Thailand, pp.S:6:1— S-6:6 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996