Chroma keying video over video

G

Ghatt

Member
We're having an issue with laying a video clip over another clip. The shot is basically an over the shoulder with a book open and the "book page" being green so we can chroma key it out later. We're trying to lay over another video clip (idea being that you open the book and an image is playing) but here's the issues we're having. Can anyone give us some guidance?

1) The superimposed video clip is much bigger than the page. How do we resize the video clip or crop it or whatever to fit the dimensions of our green screen?

2) The overlayed clip is still transparent over the entire book clip. We tried to create a garbage matte but when we'd move the corners of the matte around the best we could do was to get it to matte out the green screen and leave everything else. Is there a way to "reverse" the matte so take everything OUTSIDE of the parameters and move it to the garbage matte?

Thanks in advance!
 
You really need to do this in After Effects and even then it is a bit of a struggle because the effect you need is 3D (ie not flat as in 2D).

The page is probably curled a little and not flat. Therefore it needs "shaping and lighting effects that are 3D.

Mattes in AEFX can be inverted easily. You will need corner pinning , scaling and rotation at very least. Opacity will be helpful as will Levels.

Post up the two scenes as screen grabs if you wish.
 
We paid close attention to making sure the plans and paper were flat. It's not a "book" in the sense a 500 page novel, I guess I should've explained it better. It's a portfolio so it's just a front and back cover.

The concept is that it'll be for our reel where, if it were say a resume or a model's portfolio, you'd have something tangible to open. Since it's video, we can't put videos into a tangible device and we thought this would be a creative way to do it.

Thanks for the feedback. We'll try playing around with it and also take a look at mocha.
 
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