[Gdal-dev] Re: gdal_merge.py hdf aster dem

[Frank Warmerdam]

Maciek Sieczka wrote:
> Hi!
> 
> I have about 40 adjacent hdf Aster DEM files which I want to merge using
> gdal_merge.py into one file.
> 
> Poblems are:
> 1 these DEMs are not taken as georeferenced and all the input files are
>    being overlayed one on another in the output file which is not
>    georeferenced either
> 2 if 20 or more files are input an error occures:
> 
> [ziutek at localhost ziutek]$ gdal_merge.py -o /home/ziutek/aster.tif -of
> GTiff -n -150 /mnt/windows/gisdane/aster/dupa/*.hdf
> ERROR 2: CPLMalloc(): Out of memory allocating -4 bytes.

Maciek,

Hmm, this is odd.  This doesn't look like a real out of memory issue. More
likely a problem with negative window sizes being used somewhere resulting
in a negative memory request.

I will need some sort of configuration that I can use to reproduce this in
order to fix it.

Hmm, I seem to remember a problem vaguely like this before.  You might want
to make sure you are using recent code (perhaps GDAL 1.2.4) before going to
all the effort of submitting a bug report.


> Each file is circa 25 MB, I have 512 MB RAM, 4 GB swap and plenty of free
> disc space. DEMs are in UTM and are accompanied by *.met files. OpenEV
> handles their georeferencing properly but gdalinfo gives a following:

I don't see any obvious reason that OpenEV would have georeferencing for a
file when gdalinfo reports nothing.  This may require some "digging into".
If you can provide one file that demonstrates this issue I can likely
figure out what is wrong.

Of course "gdal_merge"ing a bunch of files isn't going to work properly if
they aren't georeferencined in a supported way unless they happen to all
have exactly the same real-world location and file size.   Note that gdal_merge
does not support GCPs, only north-up geotransforms.

Best regards,
-- 
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