Expert advice needed on difficult key…

[Anonymous]

Hi all

I really need you advice on keying a non-screen blue key. Source footage looks like this:
http://users.pandora.be/sienar/projects/olifant%200001.png
http://users.pandora.be/sienar/projects/olifant%203385.png

I need to isolate the elephant head to put it on top of a man’s body. I do not want to roto all 4000 frames of this sequence…
So far my attempts at keying this (shake 2.51) have been limited in success, I keep having dreadful edge chattering in the low-contrast areas. Should I use different keyers for different areas of the head, and if so how should I combine them? I’m not sure how I could “add up” different keyers.
Or should I give up keying and just roto?

thanks for any input!

david

[Anonymous]

j’ai vu que tu venais de belgique, je m’essaye au français…

tu devrais essayer les plug in “Puffin composite wizard”, pour nettoyer l’alpha, j’ai jamais rien vu de mieux, notamment le “miracle alpha cleaner”, qui te bouche tous les trous… assez halucinant…mais je crois que c’est des plugs AE

sinon, bah y les Furnace 2 pour shake, avec le edge matte , qui peut vraiment, mais vraiment vraiment te simplifier une eventuelle roto…

Voilà voilà

pour une réponse en anglais, just ask…

[Anonymous]

You can try to isolate the head with a mask you do not need to follow the head, later using some to keyer or several keyers. Perhaps can be util to make a color correction in the head of the elephant before the key

[kuban]

Whatever you do, you will need some masks in the end. But this seems doable to me. But you will need many keys. At least a softmatte for edges, and a hard matte for inside. I don’t use shake very well, but this seems a good job for modularkeyer in flame/inferno.

[Anonymous]

Thanks for all the tips.

I tried out some different approaches yesterday. I got promising results by layering different keyers with Min nodes. Problem is deciding which bits to key out in a single keying pass. Also i got a little carried away and I am now layering five primatte nodes. Maybe that’s over the top and i need to use a garbage & holdout matte, which i haven’t gotten round to just yet. was too excited at seeing my layered keys finally working.

Of course I will still need some roto for stubborn bits and the window etc.

[Ajax]

Hi daalex,

You can isolate the elephants head by using a reorder node for the blue channel. Look at the blue channel and notice that it has enough information to create a channel or alpha around the elephants head, then at least you would have a good starting point for filing the inner portion of the head. Then I would probably use a contrast luminance (equivilant to levels in ae or psd) and raise the levels of blue up until you get it as white as possible. Then try another reorder to isolate lets say the red channel for any other parts of the elephants head that resembles white. The idea here is to combine the reorders and contrast luminance nodes to get your alpha without doing so much of the roto. I hope you can understand the concept it really works on many things kind of like you own personal keyer, that way you can really understand how to use your channels and see the true power of shake.

Cheers, & good luck!

Ajax 😉

[Author]

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