[gdal-dev] New +axis parameter in PROJ.4 trunk and gdalwarp

[Flo Ledermann]

Hi all,

PROJ.4 trunk supports a new parameter "+axis" for projection strings to
define axis orientation. With this you can, for example, create an
"upside-down" projection by specifying "+axis=wsu" in your projection
string. (See http://trac.osgeo.org/proj/wiki/GenParms#Axisorientation )

I am trying to use this to create south-up hillshade images. I compiled
PROJ.4 trunk and GDAL using --with-static-proj4=/usr/local (where my
PROJ.4 is installed), but gdalwarp seems to just ignore the new
parameter - the result is the same as with the north-up projection.

Can anyone tell me if this is supposed to work and there's just
something wrong with my build, or if there is a limitation in GDAL that
prevents it from working with upside-down projections? Also if you can
give me any pointers to code where this limitation may be fixed I may be
able to contribute a patch, if the solution is not too involved.

Best,

Flo Ledermann