View Full Version : how would you pull a key on this

09 September 2002, 04:22 AM
Ok. Brain fart. Anyone have a good suggestion on how to pull a key on something like this? I've attached an image that shows what i need to key after a garbage mask has been applied. I need to keep the girl's arms. The difficult part is the skin tone matching closely to the table top color. I REEEAALLLY don't want to have to roto this whole sequence.


09 September 2002, 01:34 PM
Sorry, dude...

It's alot faster to rotomask that than to pull separate keys from different color samples and combine them. You can't even key the flesh since you have a similar tone on the table.

Fielding is another problem that is see... field merge or deinterlace it first.

09 September 2002, 02:21 PM
Yeah thats what i was afraid of. I was given this piece o junk plate..grr!!! Yeah the fielding i know...this was just a screengrab that i mocked up in photoshop to show you what i meant.

Thanks anyway :shrug:

09 September 2002, 10:11 PM
I have wasted time trying to pull mattes on source footage like this before, and while it is possible, it would take half the time to just key by hand. Here's an idea though. Use a paint operator, and fill in the arms, rather than paint out the stuff you want to drop. If you can paint the entire arm in one single stroke (using a fairly thick brush size), it will be easy to manipulate the stroke later. Then you can just turn the stroke into a selection and inverse it, turning that inversed area into your matte. Sounds time consuming, but after the first ten frames or so it flies by pretty quickly. Not the most scientific method and it won't be "ILM" precise, but I have seen it work beautifully with tough mattes like yours, especially if you apply a little blur to the matte to give it some fall-off. Tell your DP to take a class on compositing, it will save both of you anguish and time!

Good luck, friend!

09 September 2002, 08:53 PM
i guess rotoscoping the arms wonŽt be the problem - but maybe you should consider masking the arms and painting the matte for the fingers, otherwise youŽll probably need 10+ masks which will get sort of messy. also make sure to generate seperate elements of the matte so you can blur them seperately which will help alot on fast moving elements

09 September 2002, 09:01 PM
Lesson One: Don't ever, ever, say "We can fix that in post." I said this once to my boss, on a shot in which it was indeed more efficient to fix it in post. However, now everything is handed off to "fix in post." :annoyed:

09 September 2002, 10:25 AM
ugh, that has to be done in roto, no doubt about it. *sigh* i feel your pain. and i think better 10+ shapes that are perfect than 1 messy one.

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