[GRASS-user] raster attribute table problems

[Markus Metz]

On Sat, Jan 17, 2015 at 5:45 PM, Anna Petrášová <kratochanna at gmail.com> wrote:
> Hi,
>
> When importing National Landcover Dataset
> (http://www.mrlc.gov/nlcd2011.php), I would like to get the classes imported
> as raster labels. Gdalinfo reports existing attribute table where one of the
> columns is
>
>   <FieldDefn index="6">
>     <Name>Land Cover Class</Name>
>     <Type>2</Type>
>     <Usage>0</Usage>
>   </FieldDefn>
>
> r.in.gdal should be able to recognize it and use it as a label. The problem
> is that the field Usage reports 0, which represents GFU_Generic (General
> purpose field) instead of GFU_Name (Class name) and as a result r.in.gdal
> doesn't take it into account. The attributes are supposed to be stored in
> some vat.dbf file in the NLCD dataset (I was not able to open it on Ubuntu
> with LibreOffice due to some encoding problems to see what's exactly there).
> I don't understand how GDAL decides which column is generic or represents
> class name and I don't know if the problem is on GDAL's side or on the side
> of the data provider. Would it make sense to have an option in r.in.gdal to
> specify the name of the column which should be used for labels?

You can use the table option of r.in.gdal to dump the raster attribute
table in plain text, then modify the table such that it can be used as
rules option for r.category.

Markus M

>
> Thanks,
>
> Anna
>
>
>
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