How do you make an alpha matte from a video?

reflex

Well-known member
Im having some trouble. I want to take a video clips maybe something orginally like this...

knockout01.png


and then in AE i would like to get something like this for compositing...

knockout01.alpha.im.png



Is there a step by step to getting that end result? Basically I want to be able to effect certain things in the video with out having to make a mask with teh pen tool and animate it. Plus it is impossible to even mask the hair out and everything.

In the Others, ( movie with nicole kidman ) on the extra DVD they were showing some compositing stuff. and they where showing all the layers. They were using mattes like this on parts of the video to be able to effectively add effects to certain things. I.E. mist and fog to the back ground and a little bit to some people in the middle place between the front most character and the background and then none on the front character.

So basically the matte would have teh character close to the camera in white, then some people behind her were grayish ( so that the mist sort of covered them ) and then the background was black so that the mist was really heavy back there....

Anyone know where I should start or what i should do?
 
You're looking at rotoscoping. Time consuming, frustrating, but the only real way to cut it out unless you shot it keyable.

In the film world you'd more likely be using an Inferno, Flame, Shake, etc because they're better at roto than AE. It can be done in AE though. It's just a laborious, manual process.
 
ok yeah that's waht i meant... if you shot it keyable... meaning if there was a background ( blue / green screen ) how could you make a matte from that?
 
If it was shot against greenscreen you can just use a keyer. Check the manual or the help menu.

note that greenscreen still takes some work to look right, especially when dealing with DV footage.
 
kai said:
You're looking at rotoscoping. Time consuming, frustrating, but the only real way to cut it out unless you shot it keyable.

In the film world you'd more likely be using an Inferno, Flame, Shake, etc because they're better at roto than AE. It can be done in AE though. It's just a laborious, manual process.

but Inferno Shake and Flame doesn't exist in PC format, does it?
 
I see, thanks.

and the problem with digital shot keying is that it is only 720*576, isn't it?
I think this is not a digital shot...
 
surf said:
I see, thanks.

and the problem with digital shot keying is that it is only 720*576, isn't it?
I think this is not a digital shot...

wait what? Who is that to? Those pictures above are from the web that i used as examples. I was just wondering how to get an moving alpha matte like the b&w one from a video clip.

So then have teh actore shot against a blue screen, and then just go in a use a keying plug in or program to adjust it and get that out of it?
 
Scottdvx100 said:
If it was shot against greenscreen you can just use a keyer. Check the manual or the help menu.

note that greenscreen still takes some work to look right, especially when dealing with DV footage.

I read this and then I was just wondering...
 
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