Intel VAAPI howto with Leia v18 nightly based on Ubuntu 18.04 server
(2015-09-29, 21:55)Hufvudet Wrote: least for me, the question remains: why would we even consider dithering when limited range is kept untouched through the chain? I don't understand which calculations might benefit from dithering in limited range. It's very obvious in full range.

I can think of three things:
  1. After scaling the picture it contains pixels that fall between the original integer values. Dithering allows to keep some of those results.
  2. YCbCr -> RGB conversion doesn't always give integer results. I'm not sure if dithering or rounding is correct. I'm guessing dithering, but maybe there is a standard that answers this? Granger rainbow might show a difference. Sunflux, would you like to do some more pixel peeping? Smile
  3. Not really keeping untouched limited range, but.. My original reason for implementing dithering was to give 3dlut and other advanced processing higher effective output precision.

If rounding to 8bit precision would leave the picture untouched, dithering won't change it.

Quote:Is it only me?
I think it's a good question.

edit: /me hides from fritsch after stirring up more trouble, sorry Tongue

Messages In This Thread
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