[gdal-dev] gdalwarp makes landcover files blocky when shrinking pixel size

Chaitanya kumar CH chaitanya.ch at gmail.com
Thu Jan 26 23:01:26 EST 2012


Try gdaladdo [1] with the resampling algo set to 'mode'. If you use the -ro
option, it will create an external overview. Check your output with
different combinations of levels.

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

On Fri, Jan 27, 2012 at 5:09 AM, John Twilley <mathuin at gmail.com> wrote:

> I am working with elevation and landcover data downloaded from the
> USGS.  I use gdalwarp to convert the data to a much smaller pixel. The
> elevation data works very nicely with cubic resampling, but the only
> resampling that works at all for the landcover data is
> nearest-neighbor and that's very blocky.  When I last worked with
> landcover data, I used a majority algorithm which produced smoother
> output -- but that algorithm is not implemented in gdalwarp.
> I am looking over the source to gdalwarp to see how hard it is to add
> a new algorithm.  Other than that, though, what options are available
> to me?  Thanks in advance!
> Jack.--
> mathuin at gmail dot com
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev

Best regards,
Chaitanya kumar CH.

17.2416N 80.1426E
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