[gdal-dev] python gdal gdal.ReprojectImage produces no data

[Jachym Cepicky]

Hi Frank (and others),

> Jachym,
>
> The problem is that your output file does not have a geotransform set,
> so ReprojectImage() does not realize the output file overlaps the
> area available from the input file.  You need to set the geotransform
> before calling ReprojectImage().  Setting the coordinate system is not
> critical since ReprojectImage() allows you to pass in an output coordinate
> system.
>
> Best regards,

Thanks, it helped. Just for the record:


from osgeo import gdal
from osgeo.gdalconst import *

# let's have georeferenced geotiff
inds = gdal.Open("elevationwgs.tif")

# create the driver
driver = gdal.GetDriverByName("GTiff")

# create new output file, note the datatype must be set
outds = driver.Create("outfile.tif",inds.RasterXSize, inds.RasterYSize,
        1,GDT_UInt16)

# set geotransform parameter
outds.SetGeoTransform(inds.GetGeoTransform())

# set the projection
outds.SetProjection(inds.GetProjection())

# do the transformation - actually no transformation at all
# projections are no longer needed, since both datasets are projected
gdal.ReprojectImage(inds, outds)

# close
outds = None
inds = None

-- 
Jachym Cepicky
e-mail: jachym.cepicky gmail com
URL: http://les-ejk.cz
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