[GRASS-user] Lost metadata?

[Markus Neteler]

On Tue, Aug 15, 2006 at 07:14:08AM +0100, Glynn Clements wrote:
> 
> 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).

In addition to that, if you use for example the ERDAS IMG format
(HFA), this message usually doesn't appear since this format
supports longer metadata.

Markus