[postgis-users] Re: when rasters in Postgis?
pvanlaake at users.sourceforge.net
Sun Sep 25 13:30:27 PDT 2005
> I think the case for managing rasters in PostGIS is more related to
> management of data and less around processing of raster, but that would be
> a logical 2nd step.
This is a good idea...
> As a second phase, it is not a big conceptual step to envision a set of
> PostGIS functions that are wrappers for GDAL to do some basic image
> manipulation and reprojections. This may not be well suited for the
> database as it is memory extensive and slow, but then people working with
> rasters kind of know what to expect.
...and this isn't.
I suppose (as a raster geek) that what is needed most is a simple mechanism
to store raster data and its associated metadata in the database and apply
the standard PostGIS functions (reprojection, resampling) and predicates
(subsetting based on proximity, etc) on it.
Considering the traditional mismatch in granularity between raster data and
database storage, the challenge is in devising an efficient storage design
that does justice to both. That design would no doubt be based on some form
of tiling of the data, but then new issues surface, such as how to deal with
the diverse input formats, how to deal with reprojection, and how to present
data in response to queries (where most user programs expect entire rasters,
not tiles of data).
Altogether, I think the whole issue requires some hard thinking.
My 2 cents,
More information about the postgis-users