In GIMP, how do I make part of image transparent manually?

Question

How can I make part of the image transparent? I tried the "Color to alpha" option in GIMP, but it's not working.

I know in Photoshop you can erase the part you don't like, and make it transparent. Does GIMP support that?

On 13.04/3.10.10 installed with apt, this answer worked easiest for me. — , Sep 08 '13 at 16:44

score 79 · Accepted Answer · edited May 04 '18 at 09:43

79

In GIMP layers can either have an alpha channel or have no alpha channel. When you try erasing parts of an image when there's no alpha channel you get backround color.

To add an alpha channel you can bring up the Layers dialog by pressing Ctrl+L, right-click on the layer you want to edit and select Add Alpha Channel there.

enter image description here

From there everything is very much like in Photoshop - i.e. Eraser tool erases to transparency, you can make a selection (using, for example, Magic Wand tool) and erase everything in it by pressing Del, etc.

edited May 04 '18 at 09:43

Black

801

answered Apr 08 '12 at 11:31

Sergey

43,665

doesn't work for me. I select the area I want to be transparent and hit Del and it still is white. – chovy May 28 '20 at 18:09

score 9 · Answer 2 · answered Apr 08 '12 at 12:04

9

If you use an eraser, that will erase to transparence. You also can select an area and press the delete key (not backspace)

answered Apr 08 '12 at 12:04

pbfy0

305

11

Without a transparent layer , it becomes white , I guess it's default background color ;-P – daisy Apr 08 '12 at 12:24
You can delete the background in the same way – pbfy0 Apr 08 '12 at 12:31
I can't believe. It worked so well. Thank u. :) – Baby Groot Aug 13 '13 at 06:54
@warl0ck It defaults to secondary color – PeterM Jun 30 '16 at 18:49
simple does it, right? – Felipe Aug 27 '16 at 21:40
What if you're on a mac and there's no delete key? – geoidesic Dec 14 '18 at 13:27
@geoidesic I think Fn + [key called delete on a Mac keyboard that's really a backspace] is equivalent to the normal delete key. – pbfy0 Dec 14 '18 at 21:57

score -1 · Answer 3 · answered Mar 02 '16 at 20:33

I think what you want to so is as follow: You blur a layer (eg image of a face) and want to remove the blur from detail areas (eg eyes, lips, eyebrows). Add alpha channel to the blur layer as suggested above, then hold down Alt as you use the eraser tool, and it will remove the effect only from the erased area. Then turn down the layer opacity until you get a just perceptible softening of the features with sharp details (eyes, lips, etc).

In GIMP, how do I make part of image transparent manually?

3 Answers3