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d0bermann
01-10-2008, 07:39 AM
Hi ppl,

I have a question in mind which I don't really know how to describe.

Think that I have to shots of the same place, with the same camera angle. No camera move.
All static. First shot involves two guys in the foreground, and something like a scenery behind them. Second shot is just the scenery, without people. First shot needs an element removed in the background that is shot correctly in the second shot. (something like an object floating in the water). So what I need to do is, somehow, analyze both shots, and auto matte (??) whatever is moving in the FIRST shot (in this case the guys), and invert this matte to mask the scenery in the SECOND shot. Hopefully, this formula will give me the scenery of the second shot with the guys of the first shot in front.

Now that I theoritically solved it, the ultimate question remains;

How do I do that?

Thanks :)

K.


p.s. After Effects is strongly preferred.
m|3
01-10-2008, 06:54 PM
Hi d0bermann...

First off... if you can post images for us to see the problem that would help.

If I've understood you correctly, you want to basically use the background from shot 2 with the foreground actors from shot 1..?

Assuming the background is not moving in both shots, then you can try using a "difference matte" effect to start. If either of your backgrounds has moving elements (you did mention there's water) then rotoscoping might be in your future.

Again, if we can see the images we'll be able to help you out more accurately.
d0bermann
01-11-2008, 07:46 AM
hi there,

I have the shots at the studio, I'll post them as soon as I can.

But diffrence matte sounds like what I need. Don't mind the water, it is perfectly still. How can I produce this diffrence matte?

Thanks again,

k.
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