[mapserver-users] Can't remove artifacts aroung polygons with Mapserver 6.0.3

[Stephen Woodbridge]

On 10/24/2013 12:40 PM, efujioka wrote:
> Through further trials and errors, I found dropping SYMBOL parameter from the
> polygon STYLE improves the image (artifacts less obvious). I should have
> noticed this before...
>
> Anyway, I still see slight artifacts and the tile image is less crisp than
> 5.2 due to anti-alias that you can't turn off??
>
> An ideal solution would be to allow to turn off anti-alias for AGG/PNG with
> RGBA, I guess. As I said before, GD/PNG with PC256 works fine (get an image
> as crisp as with 5.2 [GD/PNG with RGBA] without artifacts) but it can't make
> the layer transparent. So I think I'm stuck.

Try this for your output format:

   OUTPUTFORMAT
     NAME "agg_qn"
     DRIVER "AGG/PNG"
     EXTENSION "png"
     MIMETYPE "image/png; mode=8bit"
     IMAGEMODE RGB
     FORMATOPTION "INTERLACE=false"
     FORMATOPTION "QUANTIZE_NEW=ON"
     FORMATOPTION "QUANTIZE_DITHER=OFF"
     FORMATOPTION "QUANTIZE_COLORS=256"
     FORMATOPTION "TRANSPARENT=ON"
     TRANSPARENT ON
   END

-Steve