[gdal-dev] writing XYZ file

[denis cohen]

Hi,

Thanks for the script. It works fine except for the actual data (elevation
in my case, this is a DEM).
It does not write the correct values.

Merci

Denis



On Sat, Nov 9, 2013 at 8:02 PM, Even Rouault
<even.rouault at mines-paris.org>wrote:

> Le samedi 09 novembre 2013 10:46:20, denis cohen a écrit :
> > Hello,
> >
> > I am a new user of gdal.
> > I used gdal_translate to convert a netcdf file to xyz:
> > gdal_translate -of XYZ file.nc file.xyz
> >
> > However, the xyz file starts with the upperleft coordinate.
> > Is it possible to have it write the xyz file starting with the lower left
> > coordinate?
>
> Not directly although it wouldn't be complicated to add an option to do
> that.
>
> You can try the following GDAL Python script that will create an
> intermediary
> TIFF image that has both inverted georeferencing and imagery in a
> consistant
> way.
>
> python invert.py file.nc file_reserved.tif
> gdal_translate -of XYZ file_reversed.tif file.xyz
>
>
> ----- Begin of script invert.py ------
>
> # -*- coding: utf-8 -*-
> import sys
> from osgeo import gdal
>
> src_ds = gdal.Open(sys.argv[1])
> xsize = src_ds.RasterXSize
> ysize = src_ds.RasterYSize
> bandcount = src_ds.RasterCount
> out_drv = gdal.GetDriverByName('GTiff')
> out_ds = out_drv.Create(sys.argv[2], xsize, ysize, bandcount)
> out_ds.SetProjection(src_ds.GetProjectionRef())
> src_gt = src_ds.GetGeoTransform()
> out_gt = [ src_gt[i] for i in range(6) ]
> out_gt[3] = src_gt[3] + ysize * src_gt[5]
> out_gt[5] = -src_gt[5]
> out_ds.SetGeoTransform(out_gt)
> for j in range(src_ds.RasterYSize):
>     data = src_ds.ReadRaster(0, ysize - 1 - j, xsize, 1)
>     out_ds.WriteRaster(0, j, xsize, 1, data)
> out_ds = None
> src_ds = None
>
> ----- End of script ------
>
> Even
>
> --
> Geospatial professional services
> http://even.rouault.free.fr/services.html
>
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