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 > [email protected] > http://lists.blender.org/mailman/listinfo/bf-committers _______________________________________________ Bf-committers mailing list [email protected] http://lists.blender.org/mailman/listinfo/bf-committers
