mandag den 5. marts 2018 21.52.41 CET skrev Matthieu Moy:
> Hi,
> 
> I'm wondering what the "subtract" blend mode is supposed to do.
> 
> Looking at the source code, when opacity is 1 and ignoring clamping, the
> formula seems to be roughly "b + a - 1". That looks very much like a "add"
> operator more than a "subtract".
> 
> Actually, looking at the Git history, commit
> https://github.com/darktable-org/darktable/commit/52b057dec32ea62c62f4c968a
> 216bebf8ae89c92 turned the formula from "a-b" to essentially "b+a-max".
> 
> This looks like a bug introduced a long time ago, unnoticed because no one
> really use this operator. Is it the case? If not, what did I miss?
> 
> Thanks,

Hi,

There is a link in the documentation to a gimp doc page that explains it, and 
some modes are explained in the darktable docs.

https://www.darktable.org/usermanual/en/blending_operators.html
https://docs.gimp.org/2.8/en/gimp-concepts-layer-modes.html

Kindly,
Anders



____________________________________________________________________________
darktable user mailing list
to unsubscribe send a mail to [email protected]

Reply via email to