[postgis-users] Unique Coverage

[Dylan Lorimer]

Hi PostGIS Users,

Have what I hope is a simple problem that I'm not sure how to solve with
PostGIS. I think I need to do a self-join on 0 overlap, but I'm just not
certain.

Given a number of polygons, some overlapping, some not, I want to produce
the geometries of all non-overlapping areas...ie all unique "pixels". This
has specifically to do with catalogs of overlapping imagery over an area,
where I have polygons for each scene and want to compute unique pixels.

Would I join a table with itself to achieve this?

Cheers,
dylan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20080502/ab927343/attachment.html>