Rune <run### [at] runevisioncom> wrote:
> Despite how bad these jagged edges look, some people argue that they are
> *desirable* because they are *realistic* since real cameras work the same
> way. I don't think this makes sense. In real cameras overexposure makes a
> glow that is often much larger than a pixel. This is the job of focal blur
> (which *should* be done prior to clipping), not antialiasing.

  Incorrect.

  Focal blur is not an antialiasing/color bleeding algorithm. Focal blur
is a depth-blurring algorithm which is quite independent and has little
or nothing to do with antialiasing or color bleeding. (Focal blur has
the *side-effect* of smoothing edges even in the sharpest parts of the
image, but its true purpose is not to be an antialiasing algorithm.)

  You are correct in that the physically correct interpretation of
overbright areas in the image is that their brightness should "bleed"
to nearby pixels (the amount of bleeding depending on the brightness and
the distance of the nearby pixel).
  In practice this means that a very bright object will have a soft glow
around it (the intensity and size of the glow depending on the brightness
of the object).

  If this photographic phenomenon should be simulated, it would be the task
of an algorithm developed for that specific task. Focal blurring has nothing
to do with that. The soft glow of bright objects has nothing to do with
whether the image is sharp or blurred (it's not a question of focus; it's
a question of light hitting the film; when the light is very bright it
will spread in the film).

  The option to clipped antialiasing should be an unclipped color bleeding
algorithm (which is performed besides the unclipped antialiasing).

-- 
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[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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