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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?

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    On 13.04/3.10.10 installed with apt, [this answer][1] worked easiest for me. [1]: askubuntu.com/a/50387/128334
    – user128334
    Sep 8, 2013 at 16:44
  • Why is this question on Ubuntu??!
    – Black
    May 4, 2018 at 7:32

3 Answers 3

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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.

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  • 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, 2020 at 18:09
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If you use an eraser, that will erase to transparence. You also can select an area and press the delete key (not backspace)

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    Without a transparent layer , it becomes white , I guess it's default background color ;-P
    – daisy
    Apr 8, 2012 at 12:24
  • You can delete the background in the same way
    – pbfy0
    Apr 8, 2012 at 12:31
  • I can't believe. It worked so well. Thank u. :)
    – Baby Groot
    Aug 13, 2013 at 6:54
  • @warl0ck It defaults to secondary color
    – PeterM
    Jun 30, 2016 at 18:49
  • simple does it, right?
    – Felipe
    Aug 27, 2016 at 21:40
-1

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).

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