Preserved Topic: White background to transparency

I have a previous graphic, it is a tiff image. It is in really good shape, but not perfect (edges are smooth etc...) It is a black image on a white background. I want to convert this to a transparent image but when I do, my pixelation on my edges isn't too great. I'm wondering if I should select *exactly* the black pixels and then smoothen out the edges later or if i should try and grab the smooth edges from the get go...(i haven't had luck with the latter).

Any ideas?

I'm not sure what exactly you're working with here, but check the eliminate white filter out. You'll probably have to play with it some, but I really find it handy

If you can live with the white being in the Layer, then set the Mode to RGB and change the Layer's Blending mode to Multiply. The white will still be there, but it will be transparent. Then maybe Gauss/Levels to tweak (on a copy, of course).

If I had to absolutely have transparency, I would Select > Colour Range and play until I was happy. Toss the selection into an Alpha, then Select > Invert on the Layer and hit Delete (actually, I would use a Mask, copy, hide one, then apply the Mask to the copy). Then I would go to the Alpha, give it a slight Gauss (after copying it) and tweak with Image > Adjust > Levels and see if I could come up with a better, happier selection. Operate some more from there on the original Layer after copying it (of course).

Then I would figure out more herendious ways of playing with it.


[This message has been edited by warjournal (edited 07-05-2001).]

Wow, great reply!

Ok... I think I'm satisfied, turns out that the pixels were *tight* enough on the original Tiff that *magically* selecting the white area and deleting proved to leave a nice enough transparency.

Thanks Jeni

I've been wanting something like that for a long time, I hate it when I realize all my work has been merged with a white background the whole time :P