[postgis-devel] ST_Rescale issues again

[Sandro Santilli]

On Thu, Aug 28, 2014 at 09:56:20AM +0200, Sandro Santilli wrote:
> On Thu, Aug 28, 2014 at 09:53:46AM +0200, Sandro Santilli wrote:
> > I keep getting suprised by ST_Rescale/ST_Resample/etc outputs.
> > What do you think about this.
> > 
> > 
> > Original table tiles are fully aligned: 10x10 sized, all with scale 1,-1:
> > 
> >  =# select distinct st_scalex(r), st_scaley(r), st_width(r), st_height(r)
> >  => from ( select r from res1 ) f;
> >   st_scalex | st_scaley | st_width | st_height
> >  -----------+-----------+----------+-----------
> >           1 |        -1 |       10 |        10
> >  (1 row)
> > 
> > Passing each of them through ST_Rescale with values 2.0, -2.0 result in
> > some tiles getting the new scale requested and some not:
> > 
> >  =# select distinct st_scalex(r), st_scaley(r), st_width(r), st_height(r)
> >  => from ( select ST_Rescale(r,2.0,-2.0) r from res1 ) f;
> >   st_scalex | st_scaley | st_width | st_height
> >  -----------+-----------+----------+-----------
> >           2 |        -2 |        5 |         5
> >           1 |        -1 |        5 |         5
> >  (2 rows)
> > 
> > Why is that ?
> 
> I shall add that I get this warning 4 times:
> 
>  NOTICE:  Raster has default geotransform. Adjusting metadata for use of GDAL Warp API
>  CONTEXT:  SQL function "st_rescale" statement 1
> 
> And that the deviant tile is a single one over a total of 648 tiles:
> 
>   count | st_scalex | st_scaley | st_width | st_height
>  -------+-----------+-----------+----------+-----------
>     647 |         2 |        -2 |        5 |         5
>       1 |         1 |        -1 |        5 |         5
>  (2 rows)
> 
> Should I file a ticket ?

Also, GDAL is "GDAL 1.11.0, released 2014/04/16" 

--strk;

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