[postgis-devel] [WKT Raster] Regular blocking in gdal2wktraster.py

[Mateusz Loskot]

Frank Warmerdam wrote
> Sent: Wednesday, March 25, 2009 4:38 PM
> To: PostGIS Development Discussion
> Subject: Re: [postgis-devel] [WKT Raster] Regular blocking in
> gdal2wktraster.py
> 
> 2009/3/20 Pierre Racine <Pierre.Racine at sbf.ulaval.ca>:
> > Mateusz,
> >
> > As an image is worth a thousand word, I updated the PowerPoint to
> better express the different raster datasets possibilities. Instead of
> the three categories ("continuous tiled coverage",
> > "vector-like discrete coverage" and "image warehouse") I created
> five:
> >
> > 1 - As an incomplete non-overlapping tiled coverage
> > 2 - As a complete tiled non-overlapping tiled coverage
> > 3 - As a layer of vector like discrete raster objects
> > 4 - As a “big raster” (or a series of)
> > 5 - As an image warehouse
> 
> Pierre,
> 
> I would like to encourage treating cases 1 and 2 as the same thing.
> It was never my intention that the regular blocking would require a
> complete set of tiles.

I'd like to second Frank's suggestion.

> Missing tiles would just be treated as the
> nodata value, or zero if there is no nodata value.

And that's one of purposes for whish NODATA column in RASTER_COLUMNS.

> I will attempt to update the RASTER_COLUMNS document to reflect
> this.

Thanks Frank!

> I'm also still failing to grasp how 4 (big raster) is distinct from
> the 1/2 case.

I have similar problem.

Best regards,
--
Mateusz Loskot
Senior Programmer, Cadcorp
http://www.cadcorp.com