Norbert Kern wrote:
>
> Kari, what is the difference between your method and rendering at 500 %,
> applying a mosaic filter (5 pixels) and resizing with method "nearest
> neighbor"?

http://luxlab.com/tmp/aa_mosaic.png

Scene (thin lines) from http://www.povworld.org/povray/aa.html

plane{z,0
  pigment{gradient y
    pigment_map{
      [0 rgb 1]
      [0.47 rgb 1]
      [0.47 rgb 0]
      [0.53 rgb 0]
      [0.53 rgb 1]
      [1 rgb 1]
    }
  }
  finish{ambient 1} scale .1 rotate y*-50
}

camera{location <0,0,-5> look_at 0}


The most important part is the Gaussian blur. I used 500% resolution
just to get those very thin lines. For normal a scene 200% to 300% and
1 to 1.5 pixel blur radius should be enough. The 50% blur radius seemed
to be the minimum required to prevent visible aliasing. The image will
look soft. Sharpening filter will just bring back the the jagged edges.
It's a delicate balance between artefect free and sharp image :)


_____________
Kari Kivisalo

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