export with alpha channel has a white edge

[slm437]

I exported an animation as pro res 4444 so it has an alpha channel. When compositing over darker footage there is a noticeable white edge. Is there any way to get rid of that?
It doesn't matter if I choose "do not premultiply alpha channel" or not - same result. I'm compositing in FCPX, but you can clearly see the white as well when opening the movie in QuickTime.

Any thoughts on how to fix this?

[jezjones29]

Did you try it with the 'nearest neighbor sampling' ticked in the image layers properties?

[slm437]

That option only seems available for image layers and mine are vector layers.

[slowtiger]

Haven't had that problem. But I use PNG codec.

[jahnocli]

Didn't someone use a one or two pixel feather edge in Photoshop to get rid of this?

[slowtiger]

That was the other way round: to prevent bitmaps imported to AS showing a white border.

[jahnocli]

Hmmm. It would be interesting to see whether such an import to AS had these problems on export though...

[slm437]

Haven't had that problem. But I use PNG codec.

when i export as png it's fine, no white edge. But that gives me an image sequence which is harder to work with when what I need is a movie file. Or is there an easy way to convert an image sequence into a movie?

[slm437]

I see I can convert image sequence to movie in photoshop, but a lot of extra work - it does work to eliminate the white edge. Apparently it's a bit easier to do with QTpro - which I'll get if it's my only option. But ultimately it would be nice to just export directly from AS using pro res 4444 and have a clean alpha channel.
If anyone has any further thoughts, I'd appreciate it.
Thanks

[Mejin]

Hello!

Oh yes, I got these white edge problems as well...

What I did was - I just rendered it as Quicktime with the Animation-Codec in highest quality.
(Suitable for Final Cut)
Maybe the filesize will increase - but in my project this wasn't too much.

Or you could render png and put it into After Effects - and render a ProRes from there.

But that's a workaround as well...

Best,
Mejin

[slm437]

Hello!

Oh yes, I got these white edge problems as well...

What I did was - I just rendered it as Quicktime with the Animation-Codec in highest quality.

Mejin - can you elaborate - where did you render with Animation-Codec? I don't see that option in AS. Pro res 4444 is the only option that will give an alpha channel or am i missing something?

[slowtiger]

Quicktime > PNG codec with millions+ colours. Has alpha.

[Mejin]

Hey,

well - if you do "export Animation" - there's the Output-Format - and there you can choose between the formats and then as you choose the path to render - you can then make the options(Quality-Animation, High, Maximum, Low.... and so on). Right, PNG+Alpha should work as well, I guess...
if it doesn't appear - then you have maybe not installed the Quicktime drivers(I'm not sure how excactly to do that - maybe just install Quicktime itself?!) - but I think I remember that someone else had the problem with the missing Output-Format - and there people told him to install the drivers.

Ah, I found an old topic, there someone had problems with the x64-Version.(In AS9)
viewtopic.php?f=5&t=22989&start=15

But my x64 works with Quicktime...hm... maybe you could search the forum a little bit about missing Quicktime-Output!

Best,
Mejin

[slm437]

Thanks Mejin,
the suggestion regarding Quicktime drivers seems to involve the Windows platform - I'm on Mac and running AS10.
.avi is not an option on Mac, there is no "Animation" setting for quality and no PNG+Alpha only Quicktime (PNG) which outputs with a white background.


the only video output option that I can see with an alpha channel is prores 4444 and this is where I get the white edge.

I can export using PNG as an image sequence which does give me a nice clean alpha channel. turns out I can easily convert the image sequence to prores 4444 using compressor and for now this will be my go-to solution.
It would be nice if the prores 4444 export from AS was cleaner.

Any further thoughts are helpful, meanwhile I do have a workaround.

[slowtiger]

Please try the option "QuickTime Movie" at the bottom. I think this will give you access to the "older" codecs like PNG.

And have you tried "QuickTime PNG-AAC"? There should open an options window where you can choose "Millions+ colours" which gives you Alpha.