Removing A Nasty White Background

Butch Moore wrote on 9/4/2015, 1:51 PM
I have a talking head shot against at white, wrinkled sheet. Chroma key gets about 90% of it. Unfortunately, using an additional garbage matte is troublesome because the subject couldn't stand still. I've tried multiple Chroma Key filters...just about there. But, is there a better way to remove whites and near whites from the clip?

Comments

astar wrote on 9/4/2015, 2:00 PM
Try creating a inverted matte of the white space, and it will feather better than the chroma key. Then create another matte layer that protects the whites inside the area that you want to keep. This would most likely be down utilizing the composite parent child relationship. Feather the 2 layers to suit. You will need to keyframe your garbage, and protection mattes. I am sure there are some YouTube or creative cow tuts on Vegas matte work.

jeremyk wrote on 9/4/2015, 3:47 PM
Try using the Secondary Color Corrector instead of Chroma Key. Set alpha to zero to make the matched area transparent, and you can adjust the hue range and luminance levels with more precision than you can get with Chroma Key.

Jeremy
Red Prince wrote on 9/4/2015, 10:00 PM
Quite frankly, I’m surprised it worked for even the 90%. After all, white is achromatic (i.e., has no chroma) so, theoretically, a chroma key shouldn’t work with it at all.

He who knows does not speak; he who speaks does not know.
                    — Lao Tze in Tao Te Ching

Can you imagine the silence if everyone only said what he knows?
                    — Karel Čapek (The guy who gave us the word “robot” in R.U.R.)

John_Cline wrote on 9/4/2015, 10:48 PM
Well, it's not really a chroma key, it's a luminance key.
Red Prince wrote on 9/5/2015, 6:23 PM
He said he tried numerous chroma keys. He said nothing about a luminance key.

A luminance key might work providing the entire background is within a certain luminance range but nothing else in the image (such as the whites of the eye) is in that range.

As someone else has suggested (sorry, I cannot see who while typing the reply), the built-in Sony Vegas secondary color correction key is probably the one to try because it allows fine-tuning the key based on a number of different criteria.

He who knows does not speak; he who speaks does not know.
                    — Lao Tze in Tao Te Ching

Can you imagine the silence if everyone only said what he knows?
                    — Karel Čapek (The guy who gave us the word “robot” in R.U.R.)

Butch Moore wrote on 9/5/2015, 8:20 PM
Appreciating all of the suggestions. Out of the studio until Tuesday. Will try your suggestions then and let you know how I come out! Thanks!