All photogrammetric basic tasks like exterior, relative
and absolute orientation as well as space intersection
can be resolved with feature based methods. But like
in pointwise approach also in feature based procedure,
the distribution of control features is essential for
reliable results’.
In modeling from video frames we use feature based
triangulation to solve the modeling problem. After
having a successful feature matching, the operator can
point out control features for the system. Also similar
kind of feature matching as in Chapter 4 can be
applied for detecting control feature and 2D feature in
image space correspondence. Before the final bundle
adjustment, all those feature lines have to be rejected
from sample space which are parallel or nearly
parallel with the image base line. An exception is
when those lines have a predetermined intersection
between lines with different direction properties.
Otherwise, this would lead into a singularity problem
in the estimation. Also the use of parallel imaging
strips like in aerial photography will eliminate this
problem.
6. SUMMARY
The proposed algorithm combines automatic ob-
servation extraction, robust feature matching and use
of linear features in modeling. The idea has been to
utilize the power of LSQ-estimation by increasing the
redundacy . This has been done in two ways; using
massive number of frames in observation extraction
phase and including all edge points of an object
feature to determine its parameters.
The automation has not been carried out through the
whole process, but only on most computing consuming
phases. The operator inspection and assistance will be
used in the process to guarantee the convergence of
the system.
7. REFERENCES
' Mulawa, D.C., Mikhail, E.M., 1988. Photogrammetric
Treatment of Linear Features. In: Int. Arch.
Photogrammetry and Remote Sensing, Kyoto, Japan,
Commission III.
? Mulawa, D.C., 1989. Estimation and
photogrammetric treatment of linear features. UMI
Dissertation information service, Purdue, p.312.
* Rosenfeld, A., Kak, A., 1982. Digital picture
processing. Vol. 1-2, Computer Science and Applied
Mathematics, Academic Press, Orlando, 2nd edition.
“ Canny, J., 1986. A Computational Approach to Edge
Detection. IEEE Trans. on PAMI. Vol. PAMI-8, no. 6,
pp. 679-698.
224
° Illingworth, J., Kittler, J., 1987. The Adaptive Hough
Transform. IEEE Trans. on PAMI. Vol. PAMI-9, no. 5,
pp. 690-698.
° Princen, J., Yuen, H.K,, Illingworth, J., Kittler, J.,
1989. Properties of the Adaptive Hough Transform.
Proc. of 6th Scandinavian conference on Image
Analysis, Oulu Finland, pp. 613-620.
7 Princen, J., Yuen, H.K,, Illingworth, J., Kittler, J.,
1989. A Comparison of Hough Transform Methods.
Proc. of IEEE 3rd International Conference on Image
Processing and its Applications, University of
Warwick, pp. 73-77.
* Xu, L., Oja, E., 1993. Randomized Hough Transform
(RHT): Basic mechanisms, algorithms, and compu-
tational complexities. CVGIP: Image understanding,
vol. 57, no. 2, pp 131-154.
? Heikkinen, J., 1994. Linear Feature Based Approach
to Map Revision. Int. Arch. of Photogrammetry and
Remote Sensing. Athens, Georgia, U.S.A. Commission
IV Symposium, pp. 344-351.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996
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