• Adobe After Effects

  Keying out white… Trickier than usual

  Posted by Dylan Hargreaves on June 24, 2015 at 6:10 pm

  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

  Walter Soyka replied 10 years, 10 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Walter Soyka

  June 25, 2015 at 12:40 am

  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]
• 

  Dylan Hargreaves

  June 25, 2015 at 9:02 pm

  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!
• 

  Walter Soyka

  June 27, 2015 at 4:06 pm

  [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]

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