[postgis-users] Make Empty Raster

[Pierre Racine]

> I have a bounding box with the dimensions below.
> "BOX(8.07734039737749 54.4984986588244,15.1919565742587
> 57.7505109647578)"
> I now want to make an empty raster using ST_MakeEmptyRaster, but I am not
> sure about a few params. So maybe someone can help me?
> 
> raster ST_MakeEmptyRaster(integer width, integer height,
>                                               float8 upperleftx, float8 upperlefty,
>                                                   float8 scalex, float8 scaley, float8 skewx, float8
> skewy,
>                                                      integer srid=unknown);
> 
> ST_MakeEmptyRaster( 15.1919565742587 - 8.07734039737749,
> 57.7505109647578 - 54.4984986588244,
>                                        8.07734039737749, 57.7505109647578,
>                                            ?,?,?,? (no idea what to put in skew and scale)
>                                                      4326);
> 
> I am hoping that using the degrees in height, width calculations is ok?

Maybe it's would time for you to read a bit of the documentation...

http://postgis.org/documentation/manual-svn/RT_ST_MakeEmptyRaster.html

scale is the pixel size. skew is the rotation (kind of).

Read this as well:

http://en.wikipedia.org/wiki/World_file

Pierre