[gdal-dev] gdalwarp vs gdal_translate for resizing images

[Travis Kirstine]

Even,

Thanks for your response.  I rechecked by results and it appears that the
difference may be related to the GDAL version.  I had originally been
testing using gdal 1.7.3 for the gdalwarp command and gdal 2.1.1 (osgeo4w)
for the gdal_translate command.  If I run both command using gdal 2.1.1 the
result appear the same.

Thanks

On 27 October 2016 at 09:48, Even Rouault <even.rouault at spatialys.com>
wrote:

> Le jeudi 27 octobre 2016 15:02:11, Travis Kirstine a écrit :
> > I've been looking at resampling high resolution orthophoto images (0.10m)
> > using gdalwarp vs gdal_translate to a lower resolution
> >
> > gdalwarp  -co TILED=YES -srcnodata "0 0 0" -dstnodata "0 0 0" -tr 2 2
>  -r
> > bilinear in.tif warp_2m_bilinear.tif
> >
> > compared to
> >
> > gdal_translate -co TILED=YES -a_nodata 0 -tr 2 2  -r bilinear input.tif
> > translate_2m_bilinear
> >
> >
> > It appears to me that gdal_translate produces a much "better" result with
> > reduced aliasing.  Why would the results differ?
>
> Does gdalinfo on the output of both files report the same spatial extent ?
> gdalwarp and gdal_translate have different logic to compute it when not
> explicitly mentionned.
>
>
> --
> Spatialys - Geospatial professional services
> http://www.spatialys.com
>
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