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Garbage Matte Greenscreening

Posted: Sat, 5th Jul 2008, 10:11pm

Post 1 of 5

Jake365

Force: 0 | Joined: 2nd Jul 2008 | Posts: 4

Member

Now, I'm kinda new to this, so please help me out.

Say you had a guy, and you wanted to put something behind him, but you didn't use a greenscreen. Could you possibly use a garbage matte to cut out the rest of the area, and just use the "Chroma Key" thing and clear out the black the garbage matte made? And then add a picture?

Thanks in Advance!
Posted: Sun, 6th Jul 2008, 12:03am

Post 2 of 5

Mandalorian

Force: 1905 | Joined: 24th Feb 2006 | Posts: 266

VisionLab User VideoWrap User Windows User

Gold Member

You would probably use a mask and rotoscope your actor very carefully, then just put an image beneath your footage. It would definitely be a lot easier with a greenscreen though, since rotoscoping an actor is a very time consuming process.
Posted: Sun, 6th Jul 2008, 12:05am

Post 3 of 5

FXhomer46784

Force: 493 | Joined: 24th Dec 2007 | Posts: 329

EffectsLab Pro User Windows User

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Close.

You can use a garbage matte , but there is no need to keyout the black as the "black" area isn't really black, it's see-through (that's what a garbage matte does, removes an area of the picture entirely). Although you are also correct that you could key out black just like any other color (if indeed that was necessary in some other situation).

The problem is that you would need to redraw/adjust the garbage matte on each frame (there are 25-30 frames for each second of video), so you'll find this is a very tedious method that can take hours for a shot that lasts just a few seconds. Greenscreening is much eaiser.

EDIT: Mandalorian is apparently a faster typist than me. BTW, if you have the budget, I think there are also programs that will find the mask lines for you with some degree of accuracy, but they are a few thousand dollars.
Posted: Sun, 6th Jul 2008, 2:37am

Post 4 of 5

Mandalorian

Force: 1905 | Joined: 24th Feb 2006 | Posts: 266

VisionLab User VideoWrap User Windows User

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One of those programs is Silhouette. You can create seperate roto masks and it can track them. They also have that feature in one of the Imagineer programs, called a planar tracker. It can help roto faster, but it won't do all the work for you. They are both expensive though, like already stated.
Posted: Thu, 17th Jul 2008, 9:38pm

Post 5 of 5

Jake365

Force: 0 | Joined: 2nd Jul 2008 | Posts: 4

Member

Thanks!
I kinda thought that was what it would do, but just making sure.