POV-Ray : Newsgroups : povray.documentation.inbuilt : Some stuff related to output file formats : Re: Some stuff related to output file formats Server Time
25 Sep 2021 15:09:18 EDT (-0400)
  Re: Some stuff related to output file formats  
From: clipka
Date: 30 Sep 2018 17:43:05
Message: <5bb14369@news.povray.org>
More:

(7) Output File Dithering:

The following dithering algorithms are supported:

+ Ordered dithering algorithms:

- `B2`..`B4`: Bayer pattern dithering using 2x2, 3x3 or 4x4 patterns,
respectively
- `BN`: {{New}} in version 3.8, blue noise pattern dithering using a
64x64 pattern.
- `BNX`: {{New}} in version 3.8, same as BN, but using the pattern's
inverse for the R and B channels.

+ Error diffusion dithering algorithms:

- `AT`: {{New}} in version 3.8, Atkinson error diffusion dithering
- `BK`: {{New}} in version 3.8, Burkes error diffusion dithering
- `D1`: Simple 1-dimensional error diffusion dithering
- `D2`: Sierra Lite error diffusion dithering
- `FS`: Floyd-Steinberg error diffusion dithering
- `JN`: {{New}} in version 3.8, Jarvis-Judice-Ninke error diffusion
dithering
- `S2`: {{New}} in version 3.8, Two-Row Sierra error diffusion dithering
- `S3`: {{New}} in version 3.8, Three-Row Sierra error diffusion dithering
- `ST`: {{New}} in version 3.8, Stucki error diffusion dithering

[Not for docs: Absence of extra memory requirements info is deliberate;
the extra memory should be negligible in all but highly pathological
cases. Also, current info is no longer accurate, as requirements for D2
and FS have changed.]

{{New}} in version 3.8, the default is `-THbn`, i.e: dithering is off,
with `BN` being the default if only `+TH` is specified.

{{New}} in version 3.8, dithering is fully gamma-aware, i.e the overall
apparent brightness of the resulting image is faithfully reproduced.


(8) Preview Window Dithering:

In v3.8, the preview window always uses blue noise dithering [this was
Bayer 4x4 in v3.7, but I can't find it documented anywhere except in the
change logs].



I intend to write up a short(-ish) dithering tutorial based on the (new,
to be pushed soon) `distribution\scenes\output\dither_showcase.pov`
sample scene, but anyone willing to pick up that glove would be welcome.


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