Figure 2 The original image and result after amalgamation has been applied on
two objects in real raster data base.
The newly created areas can also in some cases be
kept for the purpose of performing simplification of
the form of the original objects. An acceptance rule
for this could be that more than 75 % of the borders
pixels of the new area are neighbours with one of the
original objects. Another rule also has to be used
here to ensure that the new area is not covering
something of importance.
The method presented in this paper could also be
used for exaggerating one object toward another
object, e.g., if a wetland area that is close a river, but
has a narrow strip of open fields in between. In this
case the amalgamation could be carried out between
the wetland and water objects. The newly created
area between the objects can be reclassified to wetland
after amalgamation and acceptance check.
The methodology shown here is general in the sense
that it could be used in several application areas. The
system design is aimed at generalizing topographic
area data. However, this strategy could also be used
as a post processing step after classification of satellite
images.
ACKNOWLEDGEMENTS
The support from the National Land Survey of
Sweden who financed this work is greatly acknow-
ledged. I would especially like to thank Dr. Bengt
Rystedt and my colleges at the National Land Survey
in Gávle for inspiring discussions about digital
cartography. Ialso like to thank Dr. Hans Hauska for
the comments on the paper.
138
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