Motion Tracking Keying

[Edrick Smith]

Hey I have a video file I'm working with where on a piece of paper we have a green square that would be where a photo would go. This piece of paper is tossed down onto the desk where the video will be playing. The video will be a person calling to get the viewers attention and then the camera will do a push or a zoom into the paper to make the green keying full screen. What would be the best way to track the green section that will have a video playing in it.

[Jay Oxley]

Hi,

 

We did a similar thing for a project last year. We had two options and we tried both to see which one came out better.

 

Firstly you could try after effects as that is capable of doing it but I would suggest you try Shake. Its got a lot more parameters and it match moves a great deal better.

 

Hope this helps.

 

Jay

[Scott Fritzshall]

Keep in mind that you don't actually need greenscreen unless something is crossing in front of your piece of paper, and even if something does, it may be easier to just roto it. From what you're describing, here's what I would do. Print a black square- just an outline- on the paper, to define where you want the video to go. Maybe put some small red dots just inside each corner. Film your shot, then track each corner. You may need to track it by hand at some points. Then corner-pin your video to the tracking points. That will make it follow the motion of the paper. If the paper bends or twists into anything other than a completely flat plane, you'll probably need to do some warping of the video to get it to match, but since you have that black square on the paper for reference, you can use that as a guide to where the video should be and how it should be bending. You'll then want to rotoscope anything that crosses in front of it, and color-correct the video to match the rest of the shot.