[Talk-us] UVM-SAL Buildings

Paul Norman penorman at mac.com
Sat Jun 2 03:55:42 BST 2012

> From: Phil! Gold [mailto:phil_g at pobox.com]
> Subject: Re: [Talk-us] UVM-SAL Buildings
> * William Morris <wboykinm at geosprocket.com> [2012-06-01 12:53 -0400]:
> > is orthogonalization worthwhile in this case?
> I'm not sure it is.  I tried using JOSM's orthogonalization tool on a
> number of buildings and every time got a result that was worse than the
> original data in terms of being misaligned with the imagery.  Most of
> them ended up with lines rotated close to 45 degrees from the actual
> building's walls (i.e. JOSM's orthogonalization was almost maximally bad
> in this case).

JOSM's orthogonalization can sometimes give very unusual results. If you
have a bunch of buildings in an area all aligned if you select the
buildings, select two nodes in a line (e.g. nodes from the street where the
buildings are aligned with the street) and then orthogonalize it will do
everything relative to the line joining those nodes which will often give
better results.

I'm not sure that the above method would actually help in this import.

It might be an inherent problem with the data that the buildings end up

Personally, I'm coming down on the side of it's too blobby as-is. Perhaps
there's some way to make the building-recognition algorithm make less blobby

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