Hi all.
Now working on sextante interface to grass. One problem I'm finding is:
- GRASS raster can have labels (very convenient, e.g. r.param.scale saves feature
names along with categories)
- when saving to TIFF, these are stripped
- as a consequence, the flow DTM>Features raster>Feature vector strips the
categories, and data are lost.
Any way of keeping them? Of course we can Use raster values as categories, but
keeping the labels would be much better. One way would be to pipe directly the two
GRASS commands, without exporting in between, but this is not implemented yet.
All the best.
--
Paolo Cavallini - Faunalia
www.faunalia.eu
Full contact details at www.faunalia.eu/pc
Theoretically, it wouldn't be very hard to read the labels
from the mapset in which SEXTANTE is storing the (temporary)
GRASS datasets; they are saved as plain ASCII there.
However, the host GIS for SEXTANTE must then somehow deal
with this additional data in some useful way (e.g. via a
virtual raster attribute table).
Ben
--
Benjamin Ducke
{*} Geospatial Consultant
{*} GIS Developer
benducke AT fastmail.fm
On Mon, Jun 4, 2012, at 16:45, Paolo Cavallini wrote:
Hi all.
Now working on sextante interface to grass. One problem I'm finding is:
- GRASS raster can have labels (very convenient, e.g. r.param.scale saves
feature
names along with categories)
- when saving to TIFF, these are stripped
- as a consequence, the flow DTM>Features raster>Feature vector strips
the
categories, and data are lost.
Any way of keeping them? Of course we can Use raster values as
categories, but
keeping the labels would be much better. One way would be to pipe
directly the two
GRASS commands, without exporting in between, but this is not implemented
yet.
All the best.
--
Paolo Cavallini - Faunalia
www.faunalia.eu
Full contact details at www.faunalia.eu/pc
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grass-dev mailing list
grass-dev@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-dev
Benjamin Ducke wrote:
Theoretically, it wouldn't be very hard to read the labels
from the mapset in which SEXTANTE is storing the (temporary)
GRASS datasets; they are saved as plain ASCII there.However, the host GIS for SEXTANTE must then somehow deal
with this additional data in some useful way (e.g. via a
virtual raster attribute table).
An alternative would be to make use of the GDAL raster attribute table
in both GRASS and QGIS, with the benefit that reading labels for other
raster maps imported with GDAL would also be supported.
IIUC, QGIS is currently using GDALGetRasterCategoryNames() which has
very limited functionality and supports only integer maps. In a GDAL
raster attribute table, as with GRASS-internal categories, floating
point values and data ranges are supported, e.g.
min=358.5, max=359.5, name=359 degrees ccw from east
A GDAL raster attribute table would also solve the problem of
importing/exporting color rules for floating point data types.
Markus M
On Mon, Jun 4, 2012, at 16:45, Paolo Cavallini wrote:
Hi all.
Now working on sextante interface to grass. One problem I'm finding is:
- GRASS raster can have labels (very convenient, e.g. r.param.scale saves
feature
names along with categories)
- when saving to TIFF, these are stripped
- as a consequence, the flow DTM>Features raster>Feature vector strips
the
categories, and data are lost.
Any way of keeping them? Of course we can Use raster values as
categories, but
keeping the labels would be much better. One way would be to pipe
directly the two
GRASS commands, without exporting in between, but this is not implemented
yet.
All the best.
--
Paolo Cavallini - Faunalia
www.faunalia.eu
Full contact details at www.faunalia.eu/pc
_______________________________________________
grass-dev mailing list
grass-dev@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-dev_______________________________________________
grass-dev mailing list
grass-dev@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-dev