I also did quite a few things using Mapserver in the past but mostly in the WMS and raster data area.

One thing Mapserver can do is rendering based on data values rather than just by predefined rules, which could be quite useful for river widths and the like. This was not possible in Mapnik at least not in Mapnik versions < 2.0.

Mapserver is scriptable in a couple of languages (not just Python) and this is why it has been relatively easy coding a new backend for Tirex although Perl is not quite my favourite scripting language. Of course this new backend is heavily based on the existing WMS backend.

So why did I do this? Well, last week I just stumbled upon the nice Topomap project which Max Berger is doing and unfortunately he map is limited to a very small area.

Hopefully I will be able to provide a map of this style for a couple of other areas real soon now. I’m especially interested in islands with good hiking options, the so called Wanderinseln in German.

I just commited the changes to the Openstreetmap SVN-repository in the hope that it might be useful for others as well.

BTW, Max is using TileCache which I could probably use as well. Probably someone can enlighten me about the pros and cons of Tirex vs. TileCache.

Im Gegensatz zu einer Bachelorarbeit und einem Studium ist ein Kartenstil für ein solch dynamisches Projekt wie Openstreetmap aber niemals fertig.

Aus diesem Grund haben wir jetzt eine Arbeitsliste gegründet. Die Abonnenten dieser Liste möchten sich der Weiterentwicklung und Pflege dieses Kartenstils annehmen.

Insbesondere warten schon diverse Änderungen am internationalen Stil auf ihre Portierung.

Über weitere Mitstreiter, die mit der Mapnik Toolchain und Subversion umgehen können würden wir uns freuen.

Es geht bei der Liste ausdrücklich nicht um Diskussionen was man darstellen sollte und was nicht. Dafür gibt es talk-de und das Forum.

Was die Technik betrifft ist der Server leider sehr langsam und stellt derzeit auch nur Europa zur Verfügung. Das ändert sich hoffentlich bald wenn wir unseren eigenen Server bekommen.

Wenn jemand den Betreiber eines Rechenzentrums kennt der dem Openstreetmap Projekt etwas gutes tun möchte möge sich umgehend bei mir melden. Wir bräuchten etwa 3HE Platz in einem Serverschrank.

A few weeks ago a few austrian mappers contacted me because we are now allowed to us the WMS server at http://geoimage.at/ for mapping.

Unfortunately the data is currently only available in an austrian koordinate system (EPSG:31287). With EPSG:4326 beeing unavailable this is in fact a violation of the WMS spec

This could however be easily fixed using UMN-Mapserver as WMS-proxy, but unfortunately we are not allowed to do this at wms.openstreetmap.debecause we are not permitted to set up a cascading WMS based on their rules.

Anyway, with my wms.openstreetmap.de setup already using the python wsgi-interface (apache mod_wsgi) I thought that a standalone UMN-Mapserver based WMS-server should be very easy to hack, given the fact, that all the difficult stuff is already available in python and mapscript. Well, my presumption proved to be true

So here is my standalone WMS-server written in roughly 100 lines of python code.

As far as geoimage.at is concerned, there are already other solutions at the OSM-Wiki page, but this was fun to hack and might be useful for other purposes as well. An advantage of my solution is that it is possible to use the Austrian GIS-grid file for reprojection to achieve the highest possible accuracy. For this purpose the proj4-definition for EPSG:31287 (defined in /usr/share/proj/epsg on Linux) must look like this:

<31287> +proj=lcc +lat_1=49 +lat_2=46 +lat_0=47.5 +lon_0=13.33333333333333 +x_0=400000 +y_0=400000 +ellps=bessel +units=m +nadgrids=/path/to/GIS_GRID_austria.gsb +no_defs

I would be interested in feedback on how to get this to work on Windows as well. Talking about Linux this has only been a matter of typing apt-get install python-mapscript and adjusting the proj4 definition file to use the GIS-grid.

The following table is probably not complete so please post your suggestions if you know about other tools.

I just tested FOSS and web based tools because commercial applications like TTQV tend to be running on windows only anyway.

So here is the current state of the tools I checked. What I would really like to see in the future is a gpsies.com like semi-automatic-routing feature but based on osm instead of google.

My current workflow ist still using about 2 or 3 of these tools because fortunately all of them are able to read/write GPX file format.

Currently I just set up a hack which will translate tile requests into WMS to allow using them in viking. This is basically the same setup (with a slightly modified mapfile) already in use at wms.openstreetmap.de and available from Openstreetmap SVN.

An example tile URL for this kind of setup would be http://wms.gegg.us/tms/DOP_RGB/12/2143/1406.png. Please note that this data has not been approved for Openstreetmap use so please do not use these tiles for mapping.

Starting from Version 9.0 PostgreSQL will however include an extension called hstore which is available as a backport for current Versions of PostgreSQL (8.3 and 8.4) and even as a debian package.

Using this extension an additional key/value table is no longer needed.

Already back in March I commited a patch for osm2pgsl which would allow for storage of tag objects inside such a hstore column.

An hstore is basically what is known as hash (perl) or dictionary (python) in scripting languages. A datatype for storage of key value pairs – well suited for storage of OSM data tags.

Talking about python I took me quite some time to figure out how to convert a hstore result from an SQL query so here is how it works:

q="select (each(tags)).key,(each(tags)).value from ... where ..."
cur.execute(q)
rows = cur.fetchall()
hstore=dict(rows)

Back to the actual hstore issue…

In the meantime people are actually starting to use this stuff and MaZder even wrote a HOWTO document (currently in german language only) on howto set up such a database.

So here are the projects currently using hstore that I am aware of:

• Query-to-map
• Map Styles on the Wikimedia Toolserver
• Open Link Map
• Mail and Phone Map
• Open Brewpub Map (my own pet project)

Once again I have been doing most of the technical work which needed to be done behind the scenes. While wms.openstreetmap.de has been up and running for a few weeks now I still had to do some stuff to get the things going.

First of all I converted the mapscript from the older mod_python to the state of the art mod_wsgi. Furthermore the script has been extended to allow for individual copyright-watermarks based on mapfile entries. Tiles generated for Potlatch are now cached using the Apache Module mod_disk_cache.

The aerial image itself came as a raster image of 201 Gigapixels in the very good (in terms of image compression) but proprietary ECW-format. For legal reasons we are now using another format for actually serving the image (eating a huge 675 Gigabytes of disk-space) because the proprietary license of libecwj2 does not state very clearly if we are allowed to use it in our setup or not.

The system is powered by Mapservers mapscript written in Python to allow for convenient URLs in JOSM’s WMS plugin. In addition to this I just added support for the Online Openstreetmap Editor Potlatch while learning how to use custom tile-servers with it by chance. This is done by converting tilenames in z/x/y format to the bounding boxes needed for WMS. An Apache mod_rewrite rule provides a virtual tile-URL in the syntax needed by Potlatch and allows for direct edit-links of the available areas now provided on http://wms.openstreetmap.de

The script itself will be released as free software and added to Openstreetmap SVN.

Finally I need to mention that the system is also running on one of the Servers sponsored by german webhosting company STRATO AG.

Über die Realisierung ist man man dann jedoch, wenn man IPv6 schon länger kennt etwas verwundert. Während die Konfiguration der IPv4 Adresse automatisch per DHCP erfolgt muss man die IPv6 Adresse manuell einstellen und das obwohl bei IPv6 im Gegensatz zu IPv4 die automatische Konfiguration eigentlich das übliche Verfahren ist.

Ich habe hier zu Hause auf meinem Desktoprechner beispielsweise keine IPv6 Adresse explizit eingestellt. Stattdessen bekomme ich diese von meinem Router per radvd automatisch anhand der MAC-Adresse zugewiesen.

Es ist schon erstaunlich, dass das bei Strato nicht so funktioniert. Trotzdem natürlich kein Vergleich zu den Mitbewerbern bei denen man IPv6 nur zum völlig absurden Aufpreis von 29 €/Monat (Hetzner) oder kostenlos per Tunnel (1&1) bekommt.

Langer Rede kurzer Sinn, die drei FOSSGIS Rechner bei Strato sind also ab sofort auch per IPv6 erreichbar!

While Openstreetmap has different and arguably harder to solve problems in other areas, we fortunately do not have one in this particular case.

As a matter of fact, we simply don’t even try to rate something as relevant.
If you want to put an object into our database, because it is relevant for you, then you are welcome to do so. The now infamous discussion on the german mailinglist about dog-excrement-bags comes to mind.

The only thing where I could imagine a simular discussion is one about particular objects to be rendered in the standard map style or not.

There is only one reason for objects to be deleted from our database. They are nonexistent on a particular place, ever were and ever will be.

If they are non-existant anymore (e.g. stuff like disused railways) they have to be marked as such. Pretty black and white stuff as you can see.

Working at the booth of my employer for most of the time, I will be at the OSGeo Park on Wednesday.

This should be a good place to spread the word about Openstreetmap. Karlsruhe was the first mayor german city to be completely mapped and this is also the place where the authors of the Openstreetmap book live.

Both of them will also be present at the OSGeo Park.