Is it possible to allow a user to download a raster(imagery) that is
theextent of the map window? What can or can't be downloaded? Are there any
demo sites out there that allow the user to download databased on the map
window extent?
Oh, sure.
The most basic way is to call mode=map like you're used to seeing, and
just grab the resulting image. If you're using mapserv.js then just save
the value of map.url and there's your image.
If you mean geospatially referenced imagery, e.g. a GeoTIFF, then you
want WCS (web coverage service). It's like WMS, except that the output
is a geo-image instead of a plain image. Check the Mapserver
documentation, the howtos, and read about setting up a WCS server and
then testing it. You should find it easy to adapt the test URLs from the
tutorial over to JavaScript or HTML to do what you want.
--
Gregor Mosheh / Greg Allensworth
System Administrator, HostGIS cartographic development & hosting services
http://www.HostGIS.com/
"Remember that no one cares if you can back up,
only if you can restore." - AMANDA
