-
Keying out white… Trickier than usual
Hi folks,
Trying to key out the white background of some stock footage of a goldfish, so it’s swimming on black. I’ve tried a few methods and none are working well enough – luma key, luma matting, extract, Colorama output phase, (as per a sky replacement.)
The problem is, the goldfish fins are very whispy and its underside is pretty bright, so it’s either posterizing nastily or leaving a big white outline – even with a choker.
Am I onto a loser here? Is it time to find some alternative stock, or is there one last solution that I’ve missed?
Thanks in advance!
D
-
3 Replies
-
Without seeing the footage, it’s tough to tell, but…
You know how you can use UnMult [link] to generate alpha from black? You can do it with white, too. You just need to make an UnMult Sandwich: Invert, UnMult, Invert.
Sometimes it’s nice to top your UnMult sandwich with a little Levels (Alpha channel).
Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive | RenderBreak [blog] | Profile [LinkedIn] -
Thanks Walter – good to know for next time!
Ended up going for quite a radical technique:
1. Went to pet store
2. Purchased goldfish & tank
3. Shot goldfish against black background
4. Voila
And now my kids have a fish!
-
[Dylan Hargreaves] “3. Shot goldfish against black background”
Well, that’s cheating 🙂
Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive | RenderBreak [blog] | Profile [LinkedIn]
Reply to this Discussion! Login or Sign Up