So I have 2 images. One would be the normal image and the other has a vignette added to it. How can I subtract all the color values from the vignette version using the normal version creating an alpha png photo only from the vignette?
I tried playing with difference/subtract blend modes and Premiere Pro's difference matte. It doesn't seem to work 100% accurate. Can we even invert the colors like a keying method? I know I once saw a tutorial about this (removing a background) in Blender's video editor but I don't find it anymore. Any idea?