Semi-transparency (was: Re: [jox-tech] Re: new title)
- From: Stefan Merten <smerten oekonux.de>
- Date: Wed, 06 Oct 2010 22:25:51 +0200
Hi StefanMz!
Yesterday Stefan Meretz wrote:
And here is included the picture on white. It would be great if one
more knowledgable with Gimp etc. than me could turn white into
transparency.
Attached.
This is the trick:
Thank you very much. However, I may have been not specific enough.
Of course this works. But the problem is that the anti-aliased pixels
at the edges of the letters are not made transparent proportionally to
their amount of white but stay somewhere between black/red and white.
Zoom the result and you'll see what I mean. Or: If you have a black
underlying background then you will see the white "flashes" at the
edges of the letters.
What I want is a method to make the anti-aliased pixels become
semi-transparent.
May be my approach is wrong, however. It would be far easier if the
rendering where the anti-aliasing happens in the first place would
happen on a transparent background. But I don't know to do this either
when importing an image from PDF.
[...browsing...]
Ah, I just learned that for GIF's it's not possible to have
semi-transparent pixels. Other formats should support this, however.
[...browsing...]
I just learned that the *reverse* effect I need is called
semi-flattening. This puts some defined background color into already
existing semi-transparent pixels.
[...browsing...]
Hah - I got it!
The manual_(!) tells the important story: The `Color to Alpha` tool
already does what we need! And it works :-) ! I'll just work on this.
.. _manual: http://manual.gimp.org/en/plug-in-colortoalpha.html
Grüße
Stefan