Free-hand erasures from a selection?

Question

You might be working with a picture containing some detail that you want to eliminate or hide.

Once upon a time, in a previous version of Gimp, it worked well to select some neutral area of the picture, copy it, drag it over top of the matter to be hidden, and to anchor it in place.

But: You might want to edit your substitute piece before you anchor it. You might want to ERASE SOME EDGE THAT IS COVERING UP WHAT YOU WANT TO KEEP.

Is this doable? Is erasing from a selection now passe?

Here's one thing you can do: select/copy your neutral area, go to File>CreateFromClipboard and create a new copy of your selection. Make your erasures if needed from your new copy on the big screen. Copy that, then return to your original image and paste the copy where you want it. This could call for several repetitions till you get the substitute piece to fit where you want it. Boo, hiss.

Have you any other suggestions for erasing from a selection? CORDIALLY / MIKE

Answer 1

Better way, use a layer mask:

• Create your selection
• Edit > Copy, Edit > Paste
• Create a new layer from the floating selection (Layer > To new layer or Ctrl-Shift-N)
• Layer > Mask > Add layer mask
  • Painting the mask is really editing the alpha channel.
  • Black is transparent, white is opaque, grey tones are the whole range of opacities.
  • You can re-paint areas in white to recover the pixels if you change your mind later (which is a lot better than Undo because you can do that in any order)
• If necessary, layer and mask move together, so you can still move your pasted area (you can also scale/flip.shear/rotate it...)
• When you are done you can "apply" the mask (Layer > Mask > Apply layer mask) but you can also leave it alone
• In the same way you possibly don't need to merge down the layer. Merging is easy, un-merging if necessary is difficult.

Answer 2

The Eraser tool doesn't work on a floating selection. I don't know if this behaviour has changed from previous versions. I don't have any old versions to check. Sorry.

Yes, floating selections are a bit passé anyway. It's probably better to use actual layers instead.

Instead, try making your selection, hit Ctrl+C to copy, then do Edit > Paste as > New Layer. Select None Shift+Ctrl+A. Move the piece into position, then you can use the eraser tool on the new layer. This bypasses the whole floating selection issue.

Another possible alternative is to use the Clone Tool to paint over an object you don't want. To use it, select the Clone Tool C and then Ctrl+click on a neutral part of the image you want to use, this creates a target for the tool, and then paint over the image where you want it to be covered over.

It's also possible to clone from one layer onto another, if you need the covering patch to be on a layer of its own. Set the Clone target on the layer you wish to use, create a new layer in the layers panel, then paint with the Clone Tool on the new layer.