On Thu, Feb 10, 2011 at 7:27 AM, [email protected] <[email protected]> wrote: > I use PNG files a lot for my work. I found that 8-bit RGBA files > (non-linear, with premultiplied alpha channel) saved from the > compositor have some sort of alpha contamination in the > semi-transparent pixels that makes them imposible to compose correctly > in other than Blender's compositor.
Troy mentioned this to me a bit earlier but I didn't have a chance to look into it deeply yet. One thing that comes to mind though, is that does this only happen with PNG files? or TIFFs as well? According to the PNG spec [1], alpha is meant to be saved un-associated (un-premultiplied). If Blender is saving premultiplied alpha in a PNG then it's in violation of the spec, and I'm wondering if this may cause problems later on. It would be good to see some testing with different image formats. cheers Matt [1] http://www.libpng.org/pub/png/spec/1.2/PNG-Rationale.html -> 12.8 _______________________________________________ Bf-committers mailing list [email protected] http://lists.blender.org/mailman/listinfo/bf-committers
