[OSM-legal-talk] Licenses for Produced Works under ODbL

Frederik Ramm frederik at remote.org
Mon Oct 22 19:52:59 BST 2012


Hi,

On 22.10.2012 18:45, Igor Brejc wrote:
> What does "pre-processed or augmented" data really mean? OSM data has to
> be preprocessed to get to the form suitable for rendering. Some examples
> of preprocessing:
>
>  1. Importing it into PostGIS and flattening the geometries (like Mapnik
>     does it).

osm2pgsql does that, not Mapnik, and ODbL gives you the option of 
specifying the algorithm that produces the data from the source instead 
of handing out the data itself.

So in this case, while the osm2pgsql database is clearly a derived 
database that falls under ODbL, when someone asks you for the data you 
can say: "Get it from OSM, run it through osm2pgsql with the following 
options, and you're done."

>  2. Generalizations: simplifications of roads, polygons etc. for a
>     certain map scale.

Same process - either you share the generalized data or you share the 
algorithm that produces it. If, for example, you were to import with 
ImpOSM which does generalisations when importing, that's all you'd have 
to say.

>  3. Finding suitable label placements.
>  4. Extracting topology from the data (like multipolygon processing,
>     merging of polygons, road segments etc.).
>  5. Running other complex algorithms on the OSM data.
>
> This preprocessing can be done "on-the" fly or (in case of Mapnik) as a
> separate prerequisite step.

The boundary between what is done as a separate step, leading to a 
derived database, and what is done on the fly as part of the rendering 
process may sometimes be muddy but I guess in these situations they are 
pretty clear.

Another interesting question is how easy the algorithm you specify must 
be. It is clear that the algorithm cannot include "buy some Navteq data 
and then do this", or "buy ArcGIS and then do that" - but what if the 
algorithm includes "run this code, it will take 1000 days", or "make 
sure your machine has at least 1 TB of RAM, then continue as follows...".

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"



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