I was hoping to automate some of the process, but that didn’t work as I’d hoped. Other than that things are going well, just slowly.
Certainly let us know if you find an easy way to separate the elements. My own work recreating this was very exhausting and slow for simply the matter of rotoscoping all the elements.
I did manage to automatically create a matte, but it isn’t very accurate. But I’m going to use a similar process to do it manually. First, I extracted the starfield and planets from some of the early frames of the flyover. I couldn’t use the earliest frames due to some alignment and color issues so the ones I used were about in the middle of the Blockade Runner’s pass and shortly before the star destroyer. I picked 4 frames from two locations and overlayed them to create an average for each location and then cut out the Blockade Runner from one and laid it over the other to fill the hole. Then in Vegas, I used that image to create an overlay layer using the difference setting. That way it would cancel out the stars and planets and leave a very dark background. Then I aligned the entire flyover to that image to maximize how much was cancelled out (I also used a mask to remove the smaller moon from creating an artifact on the star destroyer). Then I exported the resulting sequence to PNG images and ran a salt & pepper filter to remove the last trace of the stars. This leaves a horrible image, but a wonder black area that if selected properly will erase the unwanted area from the original pristine frame. For the later frames where the blue engine glow still remains, I had to isolate the green layer to get a clean enough image to be usable. But it also gave me the solution to isolating the blue engine glow by taking the two images (full color and isolated green) and removing all the lighter areas of the Star Destroyer and leaving only the blue glow. Still, I have to do all the layer operations manually, though I did automate doing the salt and pepper filter and isolating the green (as a b&w image).