that actually depend on how premult is implemented 2011/12/16 Bartek Skorupa <bartekskor...@bartekskorupa.com>
> Re wiki page: When explaining math behind mixing "Over" image with > background (straight alpha) it should be: [(Over.RGB * Over.Alpha) + > (Background.RGB * (1 - Over.Alpha))]. > Formula at the page is: [(Over.RGB * Over.Alpha) + Background.RGB]. > Shouldn't it be corrected? > > In my opinion it should be as follows: > "over" image mixed with "normal" blending mode, or "mix" blending mode: > [(Over.RGB * Over.Alpha) + (Background.RGB * (1 - Over.Alpha))] > > "over" image mixed with "Add" blending mode: > [((Over.RGB + Background.RGB) * Over.Alpha) + (Background.RGB * (1 - > Over.Alpha))]. > > "over" image mixed with "Multiply" blending mode: > [((Over.RGB * Background.RGB) * Over.Alpha) + (Background.RGB * (1 - > Over.Alpha))]. > > Other blending modes - accordingly to their math. > > > Bartek Skorupa > > > On 2011-12-15, at 15:31, Brecht Van Lommel wrote: > > > Hi, > > > > Color management and alpha issues are a recurring topic, I've written > > a wiki page explaining issues with the current code and what I think > > should be done to solve them: > > http://wiki.blender.org/index.php/Dev:Source/Image/Color > > > > You might notice I'm not really mentioning OIIO/OCIO. It's a nice > > project to integrate those, but it doesn't solve current issues and is > > fairly orthogonal to the proposed changes. > > > > I might not have time to tackle this for 2.62, but it doesn't > > necessarily need to be done all in one big change. Feedback welcome, > > about what you think should be done different, and which alpha format > > convention should be used? > > > > Thanks, > > Brecht. > > _______________________________________________ > > Bf-committers mailing list > > Bf-committers@blender.org > > http://lists.blender.org/mailman/listinfo/bf-committers > > _______________________________________________ > Bf-committers mailing list > Bf-committers@blender.org > http://lists.blender.org/mailman/listinfo/bf-committers > -- ____________________ François Tarlier www.francois-tarlier.com www.linkedin.com/in/francoistarlier _______________________________________________ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers