• Adobe After Effects

  alpha mask from difference

  Posted by Jackotrades on April 22, 2007 at 4:09 pm

  Hi, i was wondering if there is a way to get an alpha mask created using a difference between to clips in After Effects?

  I’ll set the scene for you.

  Let’s say you have a clip of a static background, no movement, called Clip 1.

  Then let’s say you put an actor in the same exact place as Clip 1, and let him move about. Let’s call this Clip 2.

  So now we have 2 clips, where the only difference is the actor. Everything else in the shot is 100% identical.

  So the question is, is there a way to create an alpha mask of the actor (as he is the only difference) by using the difference in the clips? (i.e. having the program create the mask by looking at the two clips and computing an alpha mask based only on the parts that are different)

  I hope i’ve made sense here..hehe..
  And i appreciate all the info i can get.

  Danny Princz replied 19 years ago 2 Members · 3 Replies
• 3 Replies

• 

  Danny Princz

  April 22, 2007 at 5:15 pm

  effect->keying->difference matte

  who is that masked man…
  https://www.exposedideas.com/
• 

  Jackotrades

  April 22, 2007 at 8:49 pm

  That’s it.. thanks.. been so long since i’ve used After effects..hehe.. i can’t believe i missed it in my search of that function.. must be the late hours.

  Thanks
• 

  Danny Princz

  April 23, 2007 at 12:42 am

  using the “new” effect pallete can help to find things vs searching through the menus, if you have an idea what you’re looking for

  who is that masked man…
  https://www.exposedideas.com/

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