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Title
Proceedings of the Symposium on Global and Environmental Monitoring

Fig. 2 Topographic map and Landsat-5 TM image of
study area
the
4. 2.2 Definition of road-likeness
As one of measure for representing road-
likeness, Hough transformation (Ref. 6) was used.
First spectral feature road is determined and then
road segments were extracted. After that line-
likeness and directionality were checked for the
road segments followed by Hough transformation. The
extracted line segments through Hough transformation
were expanded by 3*3 pixels result in a
representation of road-1ikeness(Ref. 7).
4. 3 The results
The small portion of image showing the location
of the pure pixels of road, MIXELs and the other
pixels are shown in Fig. 4(a) while the extracted
road-like pixels were also shown in Fig. 4(b). The
result from the determination of anchor points was
shown in Fig. 5. Typical mixing ratios for the
designated pixels which are indicated in Fig.6 are
shown in Table 1 and show a reasonable proportion
for the pixels in the paddy field which apart from
the road, the pixels beside the road, the pixels in
the road and the pixels at the disconnected

1

1


_
r r\ a rl
jffl i V P I
(a) Preliminaly extracted pure road pixels, MIXELs
and the other pixels
portions. These information on proportion of the
MIXELs are useful for contextual classification. As
the matter of fact the disconnected portions are
covered with the crown of the trees beside the road
so that proportion of vegetation(paddy field) are
relatively large compared to the pixels in the road.
road
(b) Extracted road, road-like and the other pixels
Fig. 4 Extracted road, road-like and the other pixels
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