[Xastir-dev] Anti-aliasing and transparency

[Paul J. Morris]

On Mon, 20 Apr 2009 09:19:04 -0700 (PDT)
"Curt, WE7U" <archer at eskimo.com> wrote:

> > I looked into it once. One option, the quick one, was to double the
> > height and width of the drawing canvas, the use ImageMagick or
> > Graphicsmagick to scale it down.  
> 
> The algorithm for scaling down by 2 doesn't sound difficult, but
> maybe they do something special like look at the surrounding pixels
> and vote to determine the final pixel.  In any case we should be
> able to do it in C very quickly using the same algorithm that IM or
> GM use.

Building a higher resolution canvas and scaling it down for display
would also be useful for producing prettier printouts of maps, only the
scaling factor for that purpose would be more like 4. (300dpi/72dpi).  

-Paul
-- 
Paul J. Morris
Biodiversity Informatics Manager
Harvard University Herbaria/Museum of Comparative Zoölogy
mole at morris.net  AA3SD  PGP public key available