[OSM-dev] Sea polygons

[Frederik Ramm]

Hi,

Nop wrote:
> Is there a way to invert the land polygons to sea?

I guess you could easily create a world-size water polygon and then 
subtract the landmass polygons from the existing shape file using 
PostGIS functions. That would, however, leave you with one very big 
"oceans of the world" polygon, whereas the existing landmass polygons 
are diced into smaller chunks for (I suppose) more performant 
processing. There is probably a PostGIS way to achieve that too - if he 
doesn't answer here, maybe e-mail kleptog directly, AFAIK he's the one 
who did the PostGIS magic for the existing land mass polygons.

Bye
Frederik

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