) be performed 
was performed 
D in Figure 7 
er to recognize 
t, following 3 
same value. 
yuld be almost 
  
; also matched 
ognize these 2 
d. 
same value. 
ine in the first 
  
e achieved by 
ched lines are 
ed for total of 
result of line 
recognized for 
es which were 
wwe almost the 
| averaged for 
— 
Ba E 
rs: 
Figure 9. Extracted Lines as the Final Stage in the Last Image 
(Result of Final) 
6. 3D CITY MODELING 
3D data acquisition and object recognition were achieved by the 
above methods. Then, the acquired datasets are output as DXF 
format; therefore, 3D city modelling could be performed 
automatically. Figure 10 shows the 3D city model from 2 view 
points. 
7. CONCLUSION 
This paper investigates the automatic city modelling method 
using HDTV imagery, and the followings are ascertained: 
* Epipolar matching using probabilistic relaxation method 
could be performed successfully. 
* Performance of line matching was amazingly progressed. 
* Object recognition could be performed efficiently. 
Therefore, the epipolar matching and object recognition were 
combined with original line matching method which used 
optical flow, and automatic 3D city modelling could be 
performed in this paper. 
Consequently, it is expected that the method will apply for not 
only photogrammetric field but also GIS, city planning, and so 
  
on. However, there are still following issues that needed to be 
resolved before this method becomes operational. 
* Acquisition of more accurate 3D data. 
* Surface recognition for construction of roof. 
* 3D modelling for more wider region 
References from Books: 
Schenk, T., 2001. Digital Photogrammetry. TerraScience, Ohio, 
pp. 232-266. 
Takagi, M. and Shimoda, H., 1991. Handbook of Image 
Analysis. The University of Tokyo, pp.707-746. 
References from Other Literature: 
Canny, J., 1986. A Computational Approach to Edge Detection. 
In: IEEE Transaction on Pattern Analysis and Machine 
Intelligence. Vol.PAMI-8, No.6, pp.679-697. 
Chiba, N. and Kanade, T., 1998. A Tracker for Broken and 
Closely-Spaced Lines. In: Internationals Archives of 
Photogrammetry and Remote Sensing, Vol. XXXII, Part5, 
pp.676-681. 
Kunii, Y. and Chikatsu, H., 2000, Automatic Stereo Matching 
Using Optical Flow for 3D Object Modeling. In: International 
Archives of Photogrammetry and Remote Sensing, Vol. XXXIII, 
Part B5/1, pp.459-465. 
Acknowledgement 
The HDTV images in this paper were produced by Aero Asahi 
Corporation. The authors express graduate to Mr. TSURU at 
Aero Asahi Corporation for his help at this place. 
  
(a) View from Left Side 
(b) View from Right Side 
Figure 10. 3D City Model 
—503—