[GRASS-user] exporting raster map to kmz?

[Vishal Mehta]

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 <tea3rd at gmail.com> 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 at teaiii output=flood_225_50 type=area
>
> v.db.addcolumn map=flood_225_50 at teaiii columns="flood_area varchar(12)"
> v.db.update map=flood_225_50 at teaiii layer=1 column=flood_area value=225_50
> v.dissolve input=flood_225_50 at teaiii column=flood_area
> output=flood_225_50_dissolve
> v.out.ogr -c --overwrite input=flood_226_50_dissolve at 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 <
> sylvain.maillard at gmail.com> 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 <vishalm1975 at gmail.com>:
>>
>>> 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 at 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
>>> grass-user at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/grass-user
>>>
>>
>>
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>
>
>
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-- 
Vishal K. Mehta, PhD
Scientist
Stockholm Environment Institute - US
133 D St Suite F
Davis CA 95616
www.sei-us.org
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