[postgis-devel] pgraster: st_resample error

[Tom van Tilburg]

Hi all,

Can anyone tell me if it's me or postgis making the mistake.
Bottom line is that st_resample from epsg 28992 to 900913 gives me 
offsets of around 20 kilometers in Y direction.

===SQL=======
WITH
raster As (
     SELECT  ST_AddBand(ST_MakeEmptyRaster(100, 100, 195000, 450000, 1, 
1, 0, 0, 28992),'32BUI')  As rast
     ),
sub As (
     SELECT ST_Transform(ST_SetSrid(ST_Extent(ST_Resample(rast, 
900913)),900913),28992) geom FROM raster
     ),
sub2 As (
     SELECT ST_Transform(ST_Transform(ST_SetSrid(ST_Extent(rast), 
28992), 900913), 28992) geom FROM raster
)
SELECT 'st_resample' As class, ST_Extent(geom)::Text FROM sub
UNION
SELECT 'st_transform' As class, ST_Extent(geom)::Text From sub2
UNION
SELECT 'original' As class, St_Extent(rast)::Text FROM raster

===RESULT======
"st_resample";"BOX(195165.982320333 429216.850820453,195268.212183354 
429318.822637769)"
"st_transform";"BOX(195000.000157893 450000.000438874,195100.000157985 
450100.000438936)"
"original";"BOX(195000 450000,195100 450100)"

===spatial_ref_sys====
28992: "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 
+k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel 
+towgs84=565.237,50.0087,465.658,-0.406857,0.350733,-1.87035,4.0812 
+units=m +no_defs "

900913: "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 
+x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs"