[GRASS-user] Lost metadata?

[Glynn Clements]

Zenon Panoussis wrote:

> Exporting a landsat tile (i.fusion.brovey'd and i.landsat.rgb'ed),
> I get this error:
> 
> r.out.gdal input=007068_15m_rgbe format=GTiff output=007068_15m_rgbe.tif type=UInt16
> Writing format: GTiff
> Writing type:   UInt16
> Input file size is 15534, 14460
> 0Warning 1: Lost metadata writing to GeoTIFF ... too large to fit in tag.
> 
> Reading the TIFF FAQ, I get the impression that tags are strictly
> standardised, so this shouldn't happen. And anyway, this is just
> landsat, so whatever tags it has should be no surprise at all to
> r.out.gdal.
> 
> Is there any way to find what metadata are lost?
> Is there any way to avoid losing them?

AFAICT, any metadata which doesn't correspond to a known TIFF tag is
stored in a single tag in XML format. The error occurs if the XML
exceeds 32000 bytes. The code in question is in
GTiffDataset::WriteMetadata() in frmts/gtiff/geotiff.cpp.

If you need more details, you would probably be better off asking on
the GDAL mailing list. The issue is related to GDAL itself, rather
than anything in r.out.gdal (which just calls gdal_convert).

-- 
Glynn Clements <glynn at gclements.plus.com>