GML 2 OSM
=========


Overview
--------

This set of scripts is able to convert data from a GML file into a OSM file, suitable for loading into JOSM and uploading.

GML stands for "Geographic Markup Language", and is a OpenGeoSpatial Consortium standard. It only cares about the geometry of the data.

Metadata ("tags") are not defined by GML; the definition of the meanings of the metadata (i.e. xml nodes in a namespace different than wfs or gml) are defined somewhere else. For example, the EuroGeographics group publishes the EuroGlobalMap data catalogue.



Features
--------

Features, as v0.4, include:
- Use of relations to model polygons with outer and inner hulls
- Outputs API 0.5 -compatible .osm files
- Import of Points, Linestrings, MultiLinestrings and Multipolygons
- Detection of nodes used more than once: no data duplication
- Partial EGM metadata translation to OSM Map Features: Roads, Railways, Ferries, Populated places
- Best-effort attempt to fix malformed GML missing the last point (useful for the Nama City import)


Features not implemented yet:
- Full EGM metadata translation
- Add custom tags to every piece of data, to mark attribution of the data source.


Usage
-----

You'll need a recent version of PHP, along with the SimpleXML extension enabled, to run these scripts. You will need the "cs2cs" executable (part of the "proj4" suite) in order to project the data from a coordinate system to another. Run as follows:

php5 gml2osm foobar.gml baz foobar.osm

Where:
foobar.gml is the input GML file
foobar.osm is the output GML file
"baz" is the data namespace. Peek at the GML file, and you should see another namespace, not 'gml' and not 'wfs'; feed that to the script.


This has been tested against GML data obtained from the IDEE WFS (www.idee.es -> "descarga de datos"). There is no warranty that the script will work with GML data from another provider.


Legal Stuff
-------

gml2osm scripts
Copyright (C) 2007 Iván Sánchez Ortega <ivansanchez@escomposlinux.org

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.