Alpha premult in antialiasing?
I'm trying to do compositing work with some Cheetah3D renderings and real photographs. I'm getting noticeable borders in the antialiased limits of the renderings, a problem which looks like if it was related to alpha premult/nonpremult typical issues. However, perhaps the problem is more complex, as it could be related to how these border pixels are antialiased with the background: What does it happen with raytracing when you use antialiasing and your background is transparent?
Can anybody tell me what maths should I use for blending a Cheetah3D rendering on top of a real photograph? I'd expect something like CheetahRGB*CheetahAlpha + PhotoRGB*(255-CheetahAlpha), but this causes noticeable borders.
So... what maths should I use? (I've access to the compositing app source code, so I can adapt it to whatever blending formula)
Thanks!!
I'm trying to do compositing work with some Cheetah3D renderings and real photographs. I'm getting noticeable borders in the antialiased limits of the renderings, a problem which looks like if it was related to alpha premult/nonpremult typical issues. However, perhaps the problem is more complex, as it could be related to how these border pixels are antialiased with the background: What does it happen with raytracing when you use antialiasing and your background is transparent?
Can anybody tell me what maths should I use for blending a Cheetah3D rendering on top of a real photograph? I'd expect something like CheetahRGB*CheetahAlpha + PhotoRGB*(255-CheetahAlpha), but this causes noticeable borders.
So... what maths should I use? (I've access to the compositing app source code, so I can adapt it to whatever blending formula)
Thanks!!