[gdal-dev] re-gridding to a coarser grid

[Chaitanya kumar CH]

Hi,

gdaladdo [1] provides some more interpolation methods. It is designed
specifically for down-sampling.
To create a new GeoTIFF, use it with the -ro option and the levels set to
2,4,8 and 15.
The value 15 makes sure you get an overview at 1/15 th of the original
resolution.

[1]: http://www.gdal.org/gdaladdo.html

On Thu, Dec 15, 2011 at 3:06 AM, Etienne Tourigny
<etourigny.dev at gmail.com>wrote:

> The only option that you do *not* have is "mode" (the dominant value),
> which can be useful in the case of categorical (integer) data.  That
> question has been answered here:
>
> http://www.osgeo.org/pipermail/gdal-dev/2011-August/029692.html
>
> On Wed, Dec 14, 2011 at 1:35 PM, Travis Kirstine
> <traviskirstine at gmail.com> wrote:
> > Andreas,
> >
> > Yes gdalwarp support various resampling methods
> >
> > To use different resampling methods use the -r flag followed by the
> method
> >
> > eg
> >
> > gdalwarp -r near ..............
> > gdalwarp -r bilinear .............
> >
> > etc...
> >
> >
> >
> >
> > On 14 December 2011 08:26, Andreas H. <lists at hilboll.de> wrote:
> >> Travis,
> >>
> >> thanks for your answer!
> >>
> >> Regarding the resampling methods: Do they all just interpolate the
> data? I
> >> mean, when downsampling, usually I would use mean() or something similar
> >> to fill the new (coarser) grid cells. Doas gdalwarp actually do this and
> >> I'm not able to understand the documentation, or is it different?
> >>
> >> Thanks again!
> >> Andreas.
> >>
> >>
> >>> Andreas,
> >>>
> >>> gdalwarp can be used to resample images using the -tr flag or -ts flag.
> >>>
> >>> For example resample 1m image to 10m using cubic resampling and
> >>> "target resolution'
> >>>
> >>> gdalwarp -r cubic -tr 10 10 input_1m.tif output_10m.tif
> >>>
> >>> You may have an issue determining the output resolution as I believe
> >>> the resolution will be in decimal degrees rather than arc-seconds.
> >>>
> >>> Regards
> >>>
> >>> On 13 December 2011 14:52, Andreas H. <lists at hilboll.de> wrote:
> >>>> Hi,
> >>>>
> >>>> let's say I have a GeoTIFF file with a global grid in a 30 arc-second
> >>>> resolution. Which would be the appropriate GDAL command to spatially
> >>>> down-sample this file to say 0.125°?
> >>>>
> >>>> Thanks for your insight,
> >>>> Andreas.
> >>>> _______________________________________________
> >>>> gdal-dev mailing list
> >>>> gdal-dev at lists.osgeo.org
> >>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
> >>>
> >>
> >>
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-- 
Best regards,
Chaitanya kumar CH.

+91-9494447584
17.2416N 80.1426E
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