[postgis-users] Re: Proposed SQL interface for PGRaster

Patrick pvanlaake at users.sourceforge.net
Tue Dec 5 11:31:29 PST 2006


"Webb Sprague" <webb.sprague at gmail.com> wrote in message 
news:b11ea23c0612051054o6f1d84c1g14d122604f1f471c at mail.gmail.com...
>
> (3) Tiling and views: It might be worthwhile to think about having
> every raster be a set of 1 or more tiles (pgChip type?), probably of
> an optimized size, and have the user level functions deal with views
> of this set.  For example, a get_raster(raster_name, polygon_bound,
> output_type=tiff) would automagically assemble the correct pieces from
> the correct tiles and generate a single raster from a set of tiles
> that are referenced by the single name "raster_name". An insert
> statement would disaggregate into tiles and store metadata
> appropriately.
>
Hi Webb,

I agree with your observations on tiling, but I would also like to emphasize 
the usability of the tiles at the application level, rather than the 
familiar file-based storage formats such as TIFF. In other words, there 
should be a get_tile(raster, tile_index_x, tile_index_y) access method as 
well. Similar to the support of WKT representation of geometries by 
applications like we currently see in PostGIS-enabled applications, support 
for direct use of tiles will come if the interface is provided. This will in 
all likelihood be the most efficient access method.

Cheers,
Patrick