Key Color – how to add keyed out area in the center of an image?

[Kevin Camp]

there are a few ways you could do this… the most straight forward would be to duplicate the keyed footage layer, remove the color key effect from the bottom/lower footage layer and use a mask to define the area that you want to keep, but crop out the chroma wall that you want to key out. so the upper layer would give you the keyed edges and most of the subject, the lower layer would fill the hole…

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Simon Bonner]

You could also:

1) Duplicate the keyed footage twice and put both duplicates on top of the original. Turn the eyeball for the bottom layer off for now.
2) On the middle layer, delete the keying effect and set the transfer mode to Alpha.
3) Add the simple choker effect to the top layer and shrink it so that the edges are removed. Then add the fast blur effect and set it to a value of about 15 (or a value large enough that the edge is not stark but that the blur doesn’t overlap the area where the original edge was).
4) Turn the eyeball for the bottom layer back on.

This should give you what you want, with the added bonus that you don’t have to keyframe a mask. I’ve written this without AE in front of me, so if you run through it and it doesn’t work, let me know and I’ll try to steer you right.

Simon Bonner

youtube.com/simonsaysfx

[Jody Monson]

worked like a charm! thanks!

[Kevin Camp]

the mask method is a bit quick and dirty… simon’s suggestion is a very good one for many situations, and you might want to give that a try in other cases. it can save time if you had to do much keyframing of the mask.

you might also want to read some of the ae tutorials here on keying. here are a few solid techniques for keying and compositing keyed footage:

https://library.creativecow.net/articles/onneweer_barend/keyingtut.php
https://library.creativecow.net/articles/rabinowitz_aharon/junk_mattes.php
https://library.creativecow.net/articles/kramer_andrew/colorkey.php
https://library.creativecow.net/articles/coots_brendan/greenscreen.php
https://library.creativecow.net/articles/dewar_john/light_spill.php

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW