On Thu, Oct 4, 2012 at 1:26 PM, andrzej zaborowski <balr...@gmail.com> wrote: > Hi, > there's been a lot of talk at one point about abbreviating names in > the OSM database vs. doing it when processing the data at consumers > end. Since mapnik now supports alternative label placements I gave > rendering automatically abbreviated names a try. This resulted in a > (so far) tiny C library (https://github.com/balrog-kun/shrtnms) that > abbreviates the names of map features that you give it. It's very > rough but it already handles a couple of the main corner cases. It's > just a start on collecting the list of all the abbreviations > applicable in all the map languages. Currently only has basic lists > for Polish, Spanish and English, where the rules don't differ so much. > As an example German is more tricky. > > I see two ways to use it for rendering: > > * inside mapnik stylesheets, perhaps by calling the C function from > the SQL queries. This would require adding the postgres bindings, > something I've never done. > * inside osm2pgsql so that the abbreviated names are stored in table columns. > > As a quick hack I went for the latter option. It gets tricky with > hstore and multilingual maps but it works as a first attempt. I have > a patch at > http://osm.trail.pl/osm2pgsql/0002-Generate-short-name-columns.patch > that makes necessary (small) changes and a snapshot of the library > code, to osm2pgsql code. > > It ignores the actual language of a name and just tries to apply all > the possible abbreviations from its list. This will eventually need a > solution perhaps based on the location of a given map object and a > fixed list of country polygons with their main languages. Perhaps it > can use a common solution with highway shields rendering. > > One of the stylesheets at osm.trail.pl currently uses this code (only > Europe imported at this time, but I CC'd talk-us because there was a > long thread about this at one time). You can see that at z16 here > "Norbroke Street" is spelt in full: > http://a.osm.trail.pl/osmapa.pl/16/32723/21790.png > > and z15 shows Norbroke St when there's not enough space. (That > stylesheet would also merge the two segments of Norbroke St and only > show the name once, had that street not had a gap there.) > http://b.osm.trail.pl/osmapa.pl/15/16361/10895.png > > How to apply > > In addition to the osm2pgsql patch you also need to add the > auto-generated tags short_name and shortest_name to your osm2pgsql > .style file so that they end up in the mapnik db. Then in the mapnik > 2 stylesheet where you use a <TextSymbolizer > foo=bar>[name]</TextSymbolizer>, you need to change it to: > > <TextSymbolizer foo=bar > placement-type="list">[name]<Placement>[short_name]</Placement><Placement>[shortest_name]</Placement></TextSymbolizer> > > If there's a tag short_name or shortest_name in OSM data, they'll > override the autogenerated versions. The difference between those two > columns is in the degree to which they try to shorten the name, for > instance for name=West Fulton Street, the new tags will be: > > short_name=W Fulton St > shortest_name=Fulton > > For Polish if a street is named after a person, the person's > first/second names will be first shortened to their initials and then, > if necessary, omitted as is normally seen in cartography. For Spanish > all articles and prepositions are also stripped. Unfortunately if the > same rules are applied to US city names that often come from Spanish > (Los Angeles) the same thing will happend (resulting in "Angeles" > which makes no sense). I also notice that different spanish > abbreviations are used in Spain (Avenida -> Avda.) than in Latin > America (Avenida -> Av.), so it's something to have in mind if running > a global tile server or other service. > > Suggestions and lists of missing phrases are welcome, perhaps through > github (but I'm away from my main machine this week). If this is > something that users want to see in map tiles then that list will be > needed at some point even though the code doesn't yet handle all the > nuances correctly.
Very nice work. I'm not sure if this will be of help to you or not but as part of writing my ogr2osm translation for TIGER 2011 I converted the TIGER technical documentation appendix E (Feature Name Types) from PDF to a CSV file for easier processing. TIGER probably uses some abbreviations that people may not always expect but it is a handy list to have at least. https://github.com/ToeBee/ogr2osm-translations/blob/master/tiger2011_abbrev.csv Toby _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
