EuroSDR Projects - Host Ireland

ICC used the same methods as Nebel + Partner, but according to them the automatic procedures in
building extraction gave very bad results and most of the work had to be redone by hand (90%). The
Hermanni test site was simpler and automatic results were better, so less editing was needed (30%).
The use of aerial images did not modify the automatic procedures. They only helped the manual
editing. The level of automation was considered medium for Hermanni and low for other test sites.
3.1.4.5 Stuttgart University of Applied Sciences
The level of automation differed in the test sites.
In Hermanni the level of automation was high. Roof-top matching, form adaptation and mostly
parametric building models were used. Most often a saddleback-roof-building was used. In one case
the walls were taken away to combine three composite primitives. Very little manual adaptation of
parameters was required after the form adaptation and the roof-top matching. Ground height was
generally determined by matching. Copying capabilities were also used.
In Espoonlahti the level of automation varied from low to medium. Mostly polyhedral buildings were
measured. Ground height was generally determined by matching. Automatic snapping, rectangular
and planarity enforcement were frequently used for the polygon measurements. For the very few
buildings of type saddleback or hip-roof type roof-top matching, form adaptation and ground height
matching were used.
In Senaatti the level of automation was low. Mostly polyhedral building models were applied.
Matching along gutter lines did not always work. Automatic snapping, rectangular and planarity
enforcement were frequently used for the polygon measurements. Ground height was generally
determined by matching.
3.1.4.6 IGN
In the IGN method the preparation (such as DSM and true ortho processing) is fully automatic.
Cadastral plan editing and pruning is done manually. The level of automation in 3D reconstruction
varies: the model driven approach is fully automatic, straight skeleton edition and 3D shape
reconstruction is semi-automatic as is the dome edition module. Quality control is done automatically,
but also visual control is performed. The Senaatti test site is more complex so there was more human
interaction.
3.1.4.7 FOI
FOI used fully automatic procedures.
3.1.4.8 C+B Technik
In the C+B Technik method the building ground plans are needed, and if they are not available, they
have to be created manually. The degree of automation differs according to the area type and the
shape of the buildings. Especially in rural and suburb areas, where simple buildings and roof shapes
can be found and the building polygons fit to the laser scanner data a very high degree of automation
can be reached. In other areas, especially in downtown areas, where complex areas can be found, the
subdivision of complex buildings into several computation parts can support the automatic process.
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