5
2
Is there a way to do it without sacrifices?
Is it possible to copy red channel to alpha channel in gimp?
Answers
6
This does the job well:
Colors->Compose->Decompose
- Set Color Model to RGBA
- Uncheck "Decompose to layers" - my personal preference
- OK
Colors->Compose->Recompose
Swap the RED and ALPHA channels
DarthShader
Posted 2012-08-08T21:25:48.180
Reputation: 546
1
It seems that "Colors -> Color To Alpha" should do the trick if you set the color to ff0000.
S. Albano
Posted 2012-08-08T21:25:48.180
Reputation: 111
http://cdn.memegenerator.net/instances/400x/22723636.jpg – Matt Ball – 2012-08-08T21:28:09.323
Why use gimp at all? There are better suited programs for this. – None – 2012-08-08T21:28:34.090
The only program which has easy way to do this is Nuke. Also, with some hard dances it is possible in paintnet. But one does not simply install paintnet on mac. – None – 2012-08-08T21:31:06.557
2It seems that "Colors -> Color To Alpha" should do the trick if you set the color to ff0000. – S. Albano – 2012-08-08T21:35:34.750
I will answer so as to get credit, and not have it in the unanswered tab. :) – S. Albano – 2012-08-08T23:49:02.860
GIMP is great, but I haven't found anything that can grasp the simple concept of alpha as just another channel. Everything I can do with rgb I should be able to do with alpha. Photoshop is disgusting for that and gimp doesn't make it easy. – jozxyqk – 2014-05-09T11:42:58.413