[gdal-dev] How to cut a Raster map with a KML file

[Eli Adam]

Luis,
On Tue, Sep 11, 2012 at 11:14 AM, Luis Lisboa <luislisboa1975 at gmail.com> wrote:
> Hi Eli
> Probably I was not clear: When I use this it outputs a geotiff with two
> bands: 1 with the real data and another one with the mask of the pixels that
> fall inside each polygon. I just want to have an output file with one band
> (band 1) and without the mask. Is it possible?

Sometime images can clean up just be running them through
gdal_translate.  -ot or -b or -mask or some combination may
additionally be needed.  http://gdal.org/gdal_translate.html  Does
gdal_translate on your file collapse the mask band into a single band
with no data values?

rgb2pct.py can be used to convert RGB/RGBA to single band with a color
table.  I'm not sure if it would work with a two band image, one being
the mask but you can try it and see what it does.

HTH, Eli


> Thanks
> Luis
>
>
>
> On Thu, Sep 6, 2012 at 4:50 AM, Eli Adam <eadam at co.lincoln.or.us> wrote:
>>
>> Luis,
>>
>> On Wed, Sep 5, 2012 at 3:00 AM, Luis Lisboa <luislisboa1975 at gmail.com>
>> wrote:
>> > Thank you Chitanya.
>> > But it created an output file with two layers (one with the values from
>> > original file and another with a 255 for the pixels thar are inside KMZ
>> > file: How can I have produce one layer?
>>
>> I may be thinking of something else based on your description.  If you
>> got an output that has the original values in the area of the kmz and
>> an alpha mask band over the other areas I think that would be
>> expected.  You can also use -crop_to_cutline to remove that 'extra'
>> data.
>>
>> If that isn't what you are talking about, you may want to use ogr2ogr
>> to convert your kmz to a shapefile in the same projection as your
>> input raster and see if it gives you a better result.
>>
>> Bests, Eli
>>
>>
>> > Thanks
>> > Luis
>> > On Mon, Sep 3, 2012 at 5:10 PM, Chaitanya kumar CH
>> > <chaitanya.ch at gmail.com>
>> > wrote:
>> >>
>> >> Luis,
>> >>
>> >> gdalwarp has some options for this exact purpose.
>> >> The cutline can be from any of the OGR readable datasource.
>> >>
>> >> http://www.gdal.org/gdalwarp.html
>> >>
>> >> On Mon, Sep 3, 2012 at 9:34 PM, Luis Lisboa <luislisboa1975 at gmail.com>
>> >> wrote:
>> >>>
>> >>> Greetings
>> >>> I have a raster file (Geotiff) and I have a KML file with a polygon
>> >>> and I
>> >>> want to cut raster map to only have valid values inside the polygon.
>> >>> How can
>> >>> I do this using just GDAL?
>> >>>
>> >>> Usually I used to cut geotiff file with gdalwarp and but in those
>> >>> cases I
>> >>> was cutting a square (xmin xmax ymin ymax) and in this case is a more
>> >>> complex polygon
>> >>>
>> >>> Thanks
>> >>> Regards,
>> >>> Luis
>> >>>
>> >>> _______________________________________________
>> >>> gdal-dev mailing list
>> >>> gdal-dev at lists.osgeo.org
>> >>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>> >>
>> >>
>> >>
>> >>
>> >> --
>> >> Best regards,
>> >> Chaitanya kumar CH.
>> >>
>> >> +91-9494447584
>> >> 17.2416N 80.1426E
>> >
>> >
>> >
>> > _______________________________________________
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>> > gdal-dev at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
>