AGG: "fuzzy" lines at near horizontal/vertical angles ...

[thomas bonfort]

that's how the agg antialiasing works, I'm sorry but I don't think
there's a way to avoid that. As david points out, the effect is
amplified if the feature is drawn mutiple times, eg with adjacent
outlined polygons.

you can observe the same kind of output on all webmaps.

http://maps.google.com/maps?hl=en&ie=UTF8&ll=19.890723,-3.691406&spn=53.567248,81.210938&z=4&om=1
on the line between mauritania and mali

http://maps.live.com/default.aspx?v=2&cp=42.157041~-0.353622&style=r&lvl=11&tilt=-90&dir=0&alt=-1000&encType=1
on the yellow/red road east of huesca and north of tierz

...

concerning the format, you can probably get smaller images using the
formatoptions to either quantize or use a forced palette (which is
faster if the palette contains exactly 256 colors)

regards,
thomas


On Jan 8, 2008 12:40 PM, Flavio Hendry <flavio at tydac.ch> wrote:
> Hi list, hi Thomas
>
> When using AGG output, lines at near horizontal/vertical angles become
> "fuzzy". Any idea how to avoid that?
>
> Example see http://www.tydac.ch/test.png:
> - lines on the right are perfect
> - lines on the upper left area are "fuzzy"
>
> Mit freundlichem Gruss / Best Regards
> Flavio Hendry
>
> ----------------------------------------------------------------
> TYDAC Web-Site:  http://www.tydac.ch
> TYDAC MapServer: http://www.mapserver.ch
> ----------------------------------------------------------------
> ############      Mit freundlichen Gruessen / Kind Regards
> ############             mailto:flavio at tydac.ch
> ############         TYDAC AG - http://www.tydac.ch
> ####    ####        Geographic Information Solutions
> ####    ####         Luternauweg 12 -- CH-3006 Bern
> ############   Tel +41 (0)31 368 0180 - Fax +41 (0)31 368 1860
> ----------------------------------------------------------------
>
>
>