thanks for your suggestions, i dont really want to convert raster to vector at the exploratory stage i'm in- was just looking to use in-built tools that converted the raster to a png and wrappend kml around it- which is what r.out.kml did.
however, i have never before used this GUI-based "KML SUPEROVERLAY" format option that appears with v.out.ogr. thats what i've been trying and failing - just getting a black box which is correctly georegistered. i have a feeling its to do with the rendering of colors for each thematic class, and that in turn might be to do with the data type..but its just a guess. Vishal On Fri, Jul 25, 2014 at 5:30 AM, Thomas Adams <[email protected]> wrote: > Sylvain, > > I agree with your approach. However, I have run into one difficulty, which > is if the raster is very detailed (say, 1-ft Lidar) and the computational > region is relatively large (several square kilometers), GRASS has > considerable problems with the raster-to-vect conversion. The problem is > that each raster pixel is transformed to a polygon, so the result is that > there can be millions of polygons which the v.build process embedded within > r.to.vect , seems to run out of memory. This happens despite the fact that > I am running GRASS on 64-bit Ubuntu Linux with 16 GB RAM > > My process is this: > > r.to.vect -b input=flood_225.50@teaiii output=flood_225_50 type=area > > v.db.addcolumn map=flood_225_50@teaiii columns="flood_area varchar(12)" > v.db.update map=flood_225_50@teaiii layer=1 column=flood_area value=225_50 > v.dissolve input=flood_225_50@teaiii column=flood_area > output=flood_225_50_dissolve > v.out.ogr -c --overwrite input=flood_226_50_dissolve@teaiii > dsn=flood_226_50.kml format=KML > > Over the same computational region, if my grid resolution is 3-meters, I > have no problems; with 1-ft (~0.3 meters) grid resolution, I have problems. > > Regards, > > Tom > > > > > > > > On Fri, Jul 25, 2014 at 3:43 AM, Sylvain Maillard < > [email protected]> wrote: > >> Hi, >> >> kml is usually more used for vector data. >> looking at the header "<img style="margin-right: 0px;" >> src="data:image/png;base64,iVBORw0KGgo", it seems that r.out.gdal is just >> writing the binary code for your raster in an image tag in the kml file ... >> >> Have you try to transform your raster into vector ( >> http://grass.osgeo.org/grass64/manuals/r.to.vect.html) and then to >> export the vector to kml ? >> >> >> Sylvain >> >> >> >> 2014-07-23 20:26 GMT+02:00 Vishal Mehta <[email protected]>: >> >>> Hi all, >>> >>> I'm trying to classify a LANDSAT8 image. In the process, i'd like to >>> export an unsupervised classification i did (using i.cluster, followed by >>> i.maxlik) raster (type:CELL) into kml/kmz, so that I could get some visual >>> idea of the classification. the classification is from 1 to 10, with null >>> data present. >>> >>> r.out.gdal -c input=lsat2014_unsupervised@PERMANENT >>> output=C:\Users\Vishal\Documents\GIS\file3.kmz format=KMLSUPEROVERLAY >>> type=Byte nodata=0 >>> >>> but no matter what flags i try, i get a black box on google earth. >>> >>> >>> I'm just using the GUI options, Grass7svn on Windows. FYI, I do know how >>> to do this by modifying add-on r.out.kml in Linux, but it would be good if >>> i could just do my entire workflow on one platform. >>> >>> Thanks! >>> Vishal >>> >>> -- >>> Vishal K. Mehta, PhD >>> Sr Scientist >>> Stockholm Environment Institute - US >>> 133 D St Suite F >>> Davis CA 95616 >>> www.sei-us.org >>> >>> _______________________________________________ >>> grass-user mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/grass-user >>> >> >> >> _______________________________________________ >> grass-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/grass-user >> > > > > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > -- Vishal K. Mehta, PhD Scientist Stockholm Environment Institute - US 133 D St Suite F Davis CA 95616 www.sei-us.org
_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
