Using Keylight And Primatte Together

Compositing
1

Recently, someone showed me a way of using one keyer to produce a good edge matte (I am dealing with wispy hair) and another keyer to produce a holdout for the first. Trouble is, I can't remember the process. He used Dilate/Erode and then KeyMix or Max to combine the mattes. There may have been something else too... Can anyone suggest a tree?

Thanks

2

take a look in the manual under combining keyers and keying dv footage (around page 700) should sort you out.

3

QUOTE(silk @ 06/03/06, 09:47 AM) [snapback]238935[/snapback]
take a look in the manual under combining keyers and keying dv footage (around page 700) should sort you out.

Thanks, I did refer to it but it wasn't the really neat solution that had been shown to me.

A

4

I've been pulling a bunch of keys lately and this is what I got out of the tutorials:

-- I'll pull my main key with Primatte
-- then I'll pull another key with keylight, crank the screenRange right up and attach a dilate and a blur to it. Then I'll feed that second key back into the primatte holdout input. 9 times out of 10 I can then concetrate on trying to make the edges work with the primatte.

This technique also works with two primattes and two keylights, as they both have holdout inputs... Pretty basic stuff but I'm just getting started :slight_smile:

j

5

most people would tend to do it the other way around using primatte for the hard matte and keylight for the soft one. That dosnt make your method any less valid though.

6

I'm not good enough to finesse Keylight to deal with soft edges -- for whatever reason Primatte for me works better. Still trying to learn as I've also heard that many prefer Keylight for the edging. The only reason I'm using it for the holdout is that screenrange cranked really fills a matte effortlessly. Need to learn how to do that with Primatte and having to do a bunch of fg operators...

j

7

This set-up has been suggested to me:

but I can't get the dilateErode settings correct, I can't get a clean matte with no-holes and then shrink it to use as a holdout matte.

8

wow, so complicated.
remember that, primatte suggest you give it the bkg even if you don't use it, coz primmate will use the bkg information as well to produce better result. You can feed the bkg to the primatte, but in output mode, set it to key or foreground comp without bkg.
the japanese girl clips, i got quite a good key with just one primatte and roto. i bit lazy, always try use as little node as possible.

thanks

9

I understand, but the green screen on the woman file is absolutely awful. It's from the Paolini Shake 4 book and is purposely bad I think. I was looking for alternative ways to cope with this.

10

I recommend that you read the Steve Wright book which has a whole bunch of tips and tricks for dealing with real world keying problems.

Try to level the luminance of the footage so that the screen appears flat but the FG has a heavy vingetta instead. it can be done like this:

CODE
FOOTAGE = ColorWheel(720, 576, 2, 0, 1, 1, 1);
RGrad1 = RGrad(720, 576, 2, width/2, height/2, 1.06609809, min(width,height)/4,
    min(width,height)/4, 0.5, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0);
Brightness1 = Brightness(FOOTAGE, 1);
Mask(Brightness1, RGrad1, "A", 100, 0, 1, 1);