[Talk-us] Over-digitized imports?
Alan_Mintz+OSM at Earthlink.Net
Tue Aug 24 09:14:19 BST 2010
At 2010-08-19 20:24, Alan Mintz wrote:
>I'm mapping in this area:
>Along the north side of the tertiary road (whose name is not rendered, but
>is Saddle Peak Road) is a state park polygon (Topanga State Park) imported
>from CASIL. In this small segment, the road is approximated with less than
>70 nodes, while the park polygon segment alongside uses over 1200. I've
>noticed similar "beauty" in other data from this source and others (like
>the Bakersfield data mentioned recently on the list).
>Should imports make an effort to "un-smooth" such data to some extent, for
>the benefit of editing and rendering performance, storage, etc?
As a test case, I used JOSM's "Simplify Way" on the ways that make up
Topanga State Park. After playing around a bit, in advanced preferences, I
set simplify-way.max-error to 0.2, which still modeled curves to maybe
single-digit meter errors, yet removed 73% of the nodes (from 9103 to 2466).
The ways are:
I'm not embarking on a mission to simplify all ways - just taking the
(short time) to do this when I'm mapping an area anyway and see it could be
Alan Mintz <Alan_Mintz+OSM at Earthlink.net>
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