stupid question

fongaboo wrote on 3/20/2002, 3:43 AM

what is the best way to overlay a graphic or animation that has a black background over another video track? I had been using chroma key and selecting black with the color picker, but is there a more proper way?

Comments

Chienworks wrote on 3/20/2002, 1:46 PM

That is exactly what chroma-key is for. Sounds like you're doing it the smart way after all. :)

It's also possible to create graphics that have transparency or alpha channels. Either way works well. Using chroma-key is very helpful if you don't have the time, patience, or ability to edit the graphic to add the transparency.

FuTz wrote on 3/21/2002, 7:22 AM

I don't know but maybe you can switch your black to "transparent" in Photoshop so you could thereafter use it as a title... Dogworks, you think it's possible???

SonyEPM wrote on 3/21/2002, 8:35 AM

If you can save an alpha channel with your graphics and animations, Vegas can use those for keying. This is a better method that chromakeying.

fongaboo wrote on 3/23/2002, 2:37 PM

ok that's fine.. i just wanted to be sure i was doing it the right way.

any suggestions on adding alpha channel to an animation provided to me (in AVI format) on a black background? Can ImageReady accomplish it? And if so, do I have to magicwand and delete each frame manually?

DavidW12 wrote on 3/23/2002, 6:34 PM

It may work better if you do a luminance key instead of a ckey. I think that is the easiest way to key anything in VV (other than when you must use ckey).

Control_Z wrote on 3/23/2002, 6:42 PM

Black wouldn't be my first choice of color. If I can't use alpha I'll use pure green (RGB=0,255,0) as it's easier to key out. Less chance of something in the original footage being close to it (drop shadows, black hair, etc.).

fongaboo wrote on 3/24/2002, 12:30 AM

I realize.. but often the animations I am dealing with are not my creations..

How/where do you do luma-key in VV?

And any suggestions on adding genuine alpha channel to an existing AVI?

Cheesehole wrote on 3/24/2002, 11:22 PM

>>>any suggestions on adding alpha channel to an animation provided to me (in AVI format) on a black background?

if you can get your video/animation set up in Vegas so the black background is keyed out, you can render to uncompressed AVI with an alpha channel. then you'll have a video with an alpha channel.

if someone is creating animation and giving it to you in avi format, you should be able to ask the animator to provide you with an uncompressed avi with a proper alpha channel. this is standard practice when the animation is destined to be used in this way.

- ben (cheesehole!)