Re: [Cin] Color erase like GIMP

In order to have a half transparency you could try to use Blue Banana (see https://cinelerra-gg.org/download/CinelerraGG_Manual/Blue_Banana.html). Then use Reroute plugin . I've often tried to create a track with only the alpha channel that I could manipulate independently and then merge via overlays, also using the F_separatefields plugin; but I've never succeeded. Last tip: when dealing with the alpha channel it can be convenient to render a sequence of png (or OpenEXR) instead of just video formats.