Killing a premult edge?

[aaron-marine]

Hi all,

I have a few layers from photoshop saved as TGA with RGBA channels. when I take them into nuke and do a premult operation on them, like with most software...im stuck with that horrible white border.

in shake i can usually kill the border with a simple erode on the image alpha mask. does anybody want to explain to me how I might be able to accomplish this in Nuke?

thanks 

[pabs]

Try adding an unpremult before the premult.. eg if you using a colour correct use the unpremult before then the premult after.

[fxnurbs]

photoshop is already trying to premult somhow, For sensitive data, don't use the alpha from photoshop, keep your rgb unpremult in photoshop, render the alpha separately and use it as a matte