Trouble w/ transparency in CS4
by Jeff Davis on Aug 19, 2010 at 11:44:36 pm
I've imported a gif with a transparent background into a comp. I'd like to animate the gif within AE but the transparency isn't preserved, appearing as white. It seems from other posts there's no way to preserve it, so I'll need to mask it using the pen tool to draw an outline around the image I want to show. I've tried auto-trace, but it traces the boundary of the entire gif, not the image I want. I've got about 40 of these to do, so it's going to take awhile. Just wanted to see if I'm right, or if there's a faster way (or if there are any tips on getting auto-trace to work). Thanks.
Re: Trouble w/ transparency in CS4 by David Johnson on Aug 20, 2010 at 3:26:38 am
I've extremely rarely worked with GIFs in AE and it's been quite a while too so just one thought I'll throw out there ... have you considered doing what you need in Photoshop? It seems that would be easier/faster.
Re: Trouble w/ transparency in CS4 by Grant Swanson on Aug 20, 2010 at 3:34:17 am
You can try to right-click on the image in the project panel, click on Interpret Footage, then Main. If the alpha channel shows up you can select the type you created. Gifs may not support alpha channels though…
In which case you can apply Effect-->Keying-->Extract to remove the white portion (I've found that this usually works better than the Luma Key). Hopefully you don't have any white in the image itself! If you do you can always mask that to keep it in. Hope this helps.
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Just had a little play around and if you've got Flash, you can import your GIF and then export it as a PNG sequence with Alpha and then import that into AE.
If Flash isn't an option, like David said, it's probably easier to do it in photoshop and either use the magic wand tool or trace a path around it.
If you want to stay in AE you could try using the autotrace tool but make sure the channel is set to Luminance, not Alpha - that might work. Or you could try one of the other channels in the setting.
Another thing I've tried in the past to create a mask is to duplicate the layer > use colorama to bump up the contrast of the image > then set the track matte of the original to luma matte. This is hot and miss depending on how much white there is in the image.
Re: Trouble w/ transparency in CS4 by Jeff Davis on Aug 20, 2010 at 4:57:22 pm
Thanks for the feedback. I've got Flash, but the gif is a single image, not an animation, so there's no sequence to export (I didn't think png supported animations natively anyway?). I think I've figured out Auto-Trace, though, and that seems to work OK, based on Luminance.