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

Maciek Sieczka werchowyna at pf.pl
Mon Nov 15 16:19:02 EST 2004


> > 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.

I can email you the data set tomorrow about noon, but it's 420 MB zipped, do
you want it? I'm sorry but I can't put for download anywhere.

Or you may obtain a similar dataset of "Aster relative DEM" for any area via
the http://edcimswww.cr.usgs.gov/pub/imswelcome/, free of charge. It takes
about 0,5-1 hour before they inform you by email that the product is ready
for download via their ftp.

> 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.

I'm currently using CVS 2004_11_13. Should be fresh enough?

> > 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.

OpenEV handles them fine as UTM so I can eg. overlay UTM vector data for
the same area and they fit (to the extent of the "Aster relative DEM"
georefferencing accuracy). Please see the attached OpenEV screendump.

As I wrote above, I can email any data you need tomorrow about noon. One
such zipped DEM file is 10 MB.

Please let me know what you decided and thanks for your interest in my
problem.

Maciek
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