[Gdal-dev] Strange GeoTIFF error/gdal_merge.py

[Frank Warmerdam]

Markus Neteler wrote:
> On Thu, Mar 18, 2004 at 05:10:23PM -0700, Simon Perkins wrote:
> 
>>On Thu, 2004-03-18 at 10:39, Frank Warmerdam wrote:
>>
>>
>>>It had been my intention that GDAL would gracefully handle strips or
>>>tiles that have an offset and size of zero as "auto-nodata".  Apparently
>>>I did not complete that properly.   I will look into this.  Currently
>>>preinitializing to zero should resolve the problem but I realize that is
>>>not so easy to do.
> 
> 
> Sorry to be ignorant, but how to preinitialize to zero?
> 
> I was using:
> 
>  gdal_merge.py -f GTiff -n -9999 -o lomb20m.tif \
>     `find /cdimage/DEM/grid | grep w001001x`
> 
> to do the mosaiking.

Markus,

There is currently no way to pre-initialize the file with gdal_merge.py.

... ten minutes pass ...

OK, if you update from CVS there is now a -init commandline option to
gdal_merge.py that will write a given value to all pixels before it starts
merging stuff in.

eg.
   gdal_merge.py -init 0 -f GTiff -n -9999 -o lomb20m.tif \
      `find /cdimage/DEM/grid | grep w001001x`

But there is some sort of underlying problem in the GeoTIFF driver that I
really need to dig into.

PS. I added the Python wrapper for the Fill() method and used that.
Thanks Simon!

Best regards,
-- 
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