Clone Effect

[NSNH]

Hey there, new to the forum. I want to make a video of myself and a clone of me. I don't know how to achieve this effect, and I was wondering if there was a way that I could do this in virtualdub. For example, if i make a video of myself standing on the right side and I wanted to overlap another video of me standing to the left, merge them together, and make it seem that I have clone of myself. i know this may seem confusing, but I'm not exactly sure how to word it. Its like the same effect they use in Back to the future II, when Michael J. Fox is talking to his future son. Is there anyone who might help me with this?

[edDV]

Normal method done in TV and movie production would be a "chroma key". It results in a forground video and an "alpha" used to compoite the individual or object over a different background.

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