Figure 9: Comparison of a conventional area image with
a line image under motion distortions (real recordings).
Figure 10: Motion distorted sequence of area facade
samples with match partners for motion detection.
ferential motion detection and camera tracking, respectively.
In a second step we propose a re-sampling of the recorded
lines onto a virtual plane. This projection is determined by the
recorded lateral motion data and the reconstructed motion via
the algorithm explained above.
Achieving a refinement in the motion reconstruction is ex-
pected by a line matching algorithm. The latter compares
two adjacent lines by means of differences in the vertical gra-
dient. One models small shifts and scale changes between
lines using horizontal edges in the object. This is expected
to lead to the final motion reconstruction.
5 CONCLUSIONS AND FURTHER WORK
This paper presents the geometric design of a CCD line based
system for the recording of building facades for a more effi-
cient way of creating photo realistic 3D city models.
The advantages of the proposed design are the continuous
and simultaneous recording under different angles for stereo
reconstruction and obstacle elimination, and the high quality
texture recorded at an acceptable amount of data.
An introduction for the need of 3D city models and therefore
the motivation for the proposed vehicle based system, the
principal recording, requirements, and the motion disturbance
are discussed in detail.
Research and results in the first step of elimination of motion
disturbance was shown and the outline of further algorithms
was introduced.
The application of the proposed system is expected to lead
to a faster and better acquisition of the 3D geometry and
photo-texture of 3D city models.
126
6 ACKNOWLEDGMENT
We express our gratitude for the support of the Austrian Na-
tional Bank - Jubiláumfonds "System zur Erfassung und Op-
timierung digitaler Prázisionsbilder, Nr. 4871" and "System
zur Erfassung und Rekonstruktion von Gebäudefassaden, Nr.
5821".
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