[OSM-dev] c-programmer at your command

Nick Black nickblack1 at gmail.com
Fri Feb 8 12:29:27 GMT 2008


On Feb 8, 2008 11:54 AM, SteveC <steve at asklater.com> wrote:
> I agree OSM in OGR is good but doesn't osm2pgsql -> OGR -> anything
> also work?

Not really - as osm2pgsql needs PostGIS which is a bitch to install &
it relies on a defined attribute set, which is optimised for
rendering.


>
>
> On 7 Feb 2008, at 23:50, Milo van der Linden wrote:
>
> > Hello Hendri (and list)
> >
> > There is a piece of GIS-translation Open Source software that is
> > currently head of the horde.
> > It mainly consists of two pieces:
> > - OGR; for translating from an to all kind of GIS formats (including
> > shape files and postGIS)<http://www.gdal.org/ogr/>
> > - GDAL; for raster files warping, georeferencing and
> > translating.<http://www.gdal.org/>
> >
> > OGR/GDAL is solid and extremely active. Their community is even larger
> > then the OSM community consisting mostly of GIS professionals.
> > I have been posting messages to the GDAL/OGR development team to get
> > OSM
> > as a recognized datasource integrated in their software.
> >
> > Why?
> >
> > Mainly because adding OSM data format to OGR would open up the vault
> > of
> > ALL available GIS formats to get your OSM data into!
> >
> > I know there is an OSM2PostGIS and attempts have been made to create
> > stable OSM2SHP conversion software, but adding it to OGR would realy
> > speed up things.
> >
> > So, if you are well at home in C and C++, maybe you would like to
> > consider joining the OGR/GDAL team to get OSM as a solid and reliable
> > data adapter?
> >
> >
> >
> > My knowledge on OGR is excelent as a user, not as a programmer. But my
> > bet would be on OGR when I would have the skills to join them.
> >
> >
> > Hendrik Siedelmann schreef:
> >> Hello,
> >>
> >> This Project is great, and so I thought I'd like to help. As I do not
> >> own a GPS-device the only possibility is to lend my programming
> >> skills
> >> in the c language.
> >>
> >> For now I already have some (ugly) code that parses an osm file and
> >> loads the ways into an r-tree, to allow fast lookup of areas. I also
> >> added some first svg export.
> >>
> >> But befor I begin developing something that someone else has already
> >> done, what Is needed the most:
> >> - fast Database as a backend for osm-based applications
> >>
> > postGIS, definitly!
> >> - unified osm to svg converter
> >>
> > Why only stick with svg when OGR opens up a whole lot of data formats
> > for you?<http://www.gdal.org/ogr/ogr_formats.html>
> >> - ... something else I could do?
> >>
> > I think that routing is the way to enhance OSM for the near future.
> > There is an implementation of Dijkstra algorithm for postGIS
> > <http://www.cartoweb.org/cwiki/PgdijkstraWin32>
> > But it would be good to set up a good algorithm that is more general
> > and
> > based on binary files rather then database tables, thus optimizing
> > data
> > access.
> > People are already working on using OSM with qGIS for routing
> > <http://blog.qgis.org/?q=node/73> check it out!
> >> Also I have (of Course ;) ) some notes to make his Project even
> >> better:
> >>
> >> Why do nodes and ways have to be split? This makes working with osm
> >> data pretty complicated, as it requieres a database to work with, and
> >> just to get the data of one way requires many node lookups, which is
> >> slow, especially if osm data would be use on handheld devices.
> >> Couldn't nodes simply be identified by their coordinates? This would
> >> also require less memory.
> >>
> > This is one of the main issues in my opinion too. Therefor good
> > translation software needs to be made to get OSM data into a routing
> > optimized binary file structure with r-tree functionality?
> >> Bezier curves. They are currently added via post-processing, which
> >> means suboptimal results, the mapper has little influence on the
> >> appearence and there are basically no memory savings. Instead of
> >> adding a rounding tag which does not solve most of these issues, what
> >> about deriving the bezier curves from original data?
> >> Gps-Tracks a series of points, and propably also most of the other
> >> sources of map data? (I don't know). So if the mapper simply
> >> specifies
> >> that the points between two points in the track form a way, then we
> >> could derive static sets of (bezier-) map data. And route
> >> calculations
> >> and so on can be done on the original simple data.
> >>
> > Beziers are a major problem in ALL gis file formats. So if you come up
> > with a solution there is a great future for you.
> >> Well thats it for now.
> >> Here is the database I coded for now (better dont't look at it ;) ):
> >> http://minimi.dyndns.org/mkdb33.c.bz2
> >> When started it reads from a file "map_p" in the working dir, which
> >> could be a pipe from a decompressor. The program writes data to
> >> "/tmp/osm/" so be sure to create this directory!
> >> After the import is finished, the Program will ask for
> >> latitude/longitude pairs and then dump a svg file named "place.svg"
> >> in
> >> the working dir.
> >> The program is slow at the moment, so better test with a small
> >> dataset. I chose ther Germany extract of the planet dump.
> >>
> >> Here is such an svg dum:
> >> http://minimi.dyndns.org/48.78x9.12.svg.bz2
> >>
> >> hendrik
> >>
> >>
> > Good luck and welcome to the team!
> >> _______________________________________________
> >> dev mailing list
> >> dev at openstreetmap.org
> >> http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/dev
> >>
> >>
> >
> >
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> >
>
> have fun,
>
> SteveC | steve at asklater.com | http://www.asklater.com/steve/
>
>
>
>
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-- 
Nick Black
--------------------------------
http://www.blacksworld.net




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