[postgis-devel] Out of DB regression tests for ST_AsGDALRaster

[Paragon Corporation]

I'm not sure what others think of this.  I would be okay with testing with
python.  In fact I think raster already has some out of db python tests.

Ideally though:  It should follow the same tests we do for the rest of the
system and for that we use Cunit to do out of db tests.  If that's too much
of a hassle for your tests, then I would personally be okay with you using
python scripts since that's a requirement to use the raster2pgsql.py anyway
so you actually already have to use python to test your raster2pgsql loader
anyway.

+1

Wait for rest of PSC folks to make their comments. (HINT HINT PSC)

If you want to experiment with using C-Unit, the instructions are here:
http://trac.osgeo.org/postgis/wiki/DevWikiCUnit

And like I send that is the standard for non-raster PostGIS we use.  Some
examples of tests are in /trunk/liblwgeom/cunit

Speaking of Python, I've been using plpython to test your raster output
functions with a script that looks like this (but to be honest I don't
really know python -- just copy other people's stuff)
And some of my boston aerial data that I was hoping to eventually play
around with to extrude different vector features like building footprint
(lofty dream I know)

CREATE OR REPLACE FUNCTION writeraster(filename text,img bytea)
  RETURNS text
AS $$
    f = open('/postgis_images/' + filename, "w")
    f.write(img)
    return("done")
$$ LANGUAGE plpythonu;

SELECT writeraster('ab' || rid::text || '.tiff',ST_AsTIFF(rast,
ARRAY['COMPRESS=DEFLATE', 'ZLEVEL=9']))
FROM o_4_boston limit 100;

SELECT writeraster('ab' || rid::text || '.tiff',ST_AsTIFF(rast)
FROM o_4_boston limit 100;

Anyrate -- works great on my 9.1 install but my 8.4 install doesn't generate
readable images.  It could be very well a flaw in PLPython 8.4.

Outputting ST_AsPNG doesn't work on any of my installs (I mean in generating
readable images).
In fact it throws a stupid warning for this particular data  if I don't
specify the bands that I have too many when I only have 3 bands. Or at least
ST_NumBands returns 3.

SELECT writeraster('ab' || rid::text || '.png',ST_AsPNG(rast))
FROM o_4_boston limit 100;

  I'll next test with .NET and PHP to rule out PLPython idiosyncracies.  It
was just easier to whip up a PLPython example and one I can easily throw
into a torture test to stress test things.


The ST_AsJPEG for this dataset always returns black and white, but I think
it could be because my pixel ranges are higher than 256.  As I recall, I
think for the pele example you've been playing with it works fine.

Anyrate if you are interested in this dataset, I can provide these aerials
as a download file -- the sample zipped is about 30 MB, but I can throw on
my server for download since its publically available data.

Thanks,
Regina