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Hi all. If I,m working in Combustion and I use a CG image with alpha premultiply, I must unpremultiply in footage menu to make a color correction? In Shake, after unpremultiply you see the alpha area brighter and wrong if you composite with over operation. It,s the same working in Combustion?
Thank,s.
I dont quite get your question, but here goes …to colour correction without alpha you simply switch from “color+alpha” to “color” in the footage controls. The premultiply is all about what colour value you want the software to multiply the alpha channel by before the alpha is applied. this is set to black by default and blacks rgb value is 0,0,0 so it goes 0*x=x. If you change it to white then all the alpha pixels would be multiplied by 255, which would effectivly take all the transparency out of the image since it would turn all the alpha pixels to white (255,255,255) and a white alpha is a 100% opaque value.
…..(i really hope i am right about this …premultiplying has never been my strongest subject)
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