[mapserver-users] Reprojection image quality

[Paul Ramsey]

Add

PROCESSING "RESAMPLE=BILINEAR"

to your raster layer.

If you're feeling really free with your CPU cycles,
add

PROCESSING "RESAMPLE=AVERAGE"


On Mon, Sep 22, 2008 at 7:50 AM, Benoît Andrieu <bea at ixsea.com> wrote:
> Hello guys !
>
> I currently have some problems in the quality of the images produced by
> GDAL/Mapserver.
>
> We are using MapServer to serve raster imagery to NASA Worldwind.
> Our files are in UTM and Worldwind needs WGS84 images so we do reprojection
> on the fly.
> Using this, we can clearly see image quality artefacts between Worldwind
> (using WGS84, no choice) and a custom internal tool (showing original data).
>
> I can reproduce the problem using gdalwarp tool using a very simple command
> line :
> gdalwarp -multi -t_srs EPSG:4326 -srcnodata 0 -dstnodata 0 -r near
> %FileSrc%/*_p_*8bit.tif %FileDest%
>
> You can see the result in the embedded file : on the right, the original
> image and on the left, the resulting output.
>
> I suspect that using some others settings, I could improve the quality on
> gdalwarp's output in a first time and on mapserver's output in a second time
> but I don't know where to start...
>
> So if anyone could help or suggest anything, he will be welcome !!!
>
> Thanks in advance,
>
> Benoît
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
>