[gdal-dev] Question on writing a GTiff using python

[Even Rouault]

Le samedi 18 juin 2016 19:01:26, Stephen Woodbridge a écrit :
> Hi all,
> 
> I'm writing a GTiff using GDAL/Python and it is mostly working. The
> source data is coming from a NETCDF file that is georeferenced in
> Longitude from 74.1600037 to 434.160 degrees
> 
> If I use this I get:
> 
> Size is 4500, 1782
> Coordinate System is:
> GEOGCS["WGS 84",
>      DATUM["WGS_1984",
>          SPHEROID["WGS 84",6378137,298.257223563,
>              AUTHORITY["EPSG","7030"]],
>          AUTHORITY["EPSG","6326"]],
>      PRIMEM["Greenwich",0],
>      UNIT["degree",0.0174532925199433],
>      AUTHORITY["EPSG","4326"]]
> Origin = (74.160003662109375,46.987300872802734)
> Pixel Size = (0.079999959309896,0.079999959309896)
> 
> Corner Coordinates:
> Upper Left  (  74.1600037,  46.9873009) ( 74d 9'36.01"E, 46d59'14.28"N)
> Lower Left  (      74.160,     189.547) ( 74d 9'36.01"E,189d32'50.02"N)
> Upper Right (     434.160,      46.987) (Invalid angle, 46d59'14.28"N)
> Lower Right (     434.160,     189.547) (Invalid angle,189d32'50.02"N)
> Center      (     254.160,     118.267) (254d 9'35.68"E,118d16' 2.15"N)
> 
> Looks like I also need to flip the Y axis, but ignore that for the moment.

You can perhaps try the GDAL_NETCDF_BOTTOMUP=YES/NO configuration option.

> 
> Do I need to reorganize the pixels to be in the range of -180 to 180?

Not necessarily. GeoTIFF will accept any georeferencing. The choice of 
reorganizing the pixels or not depends on the expectations of the 
people/software using your GeoTIFF.

> What is the best way t do this?
> I can probably slice and splice the numpy array for each row as I copy
> it. Other options?

That's a reasonable option.

> 
> Thanks,
>    -Steve
> 
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