[Gdal-dev] "upside down" images

Matthew Perry perrygeo at gmail.com
Tue Sep 4 22:42:54 EDT 2007


Hi all,

I have a surfer binary grid that I plan to use with GDAL.
Unfortunately, GDAL is not picking up the proper coordinate space for
the image... Note that the lower and upper Y values are swapped
causing any output files to be flipped along the Y axis.

C:\Workspace\Temp\interpolation>gdalinfo svpce_5.grd
Driver: GS7BG/Golden Software 7 Binary Grid (.grd)
Files: svpce_5.grd
Size is 555, 339
Coordinate System is `'
Origin = (383371.000000000000000,3764907.000000000000000)
Pixel Size = (0.500000000000000,0.500000000000000)
Corner Coordinates:
Upper Left  (  383371.000, 3764907.000)
Lower Left  (  383371.000, 3765076.500)
Upper Right (  383648.500, 3764907.000)
Lower Right (  383648.500, 3765076.500)
Center      (  383509.750, 3764991.750)
Band 1 Block=555x1 Type=Float64, ColorInterp=Undefined
  NoData Value=1.70141e+038



I've brought this issue up before
(http://lists.maptools.org/pipermail/gdal-dev/2006-April/008499.html)
in reference to netcdf files. I was just wondering if:

a) anyone has experienced this and come up with a clean solution
(editing gcps and vrts work but are hardly a robust solution).

or

b) since this does not seem to be a driver-specific issue (or at least
it appears in both the netcdf and the surfer grd drivers), would it be
possible for GDAL to handle this case in a more generic way?



-- 
Matthew T. Perry
http://www.perrygeo.net

"You never change things by fighting the existing reality.
To change something, build a new model that makes
the existing model obsolete" - R. Buckminster Fuller



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