Replacing the Sky - Selection Masking

[Punchcard]

How can I replace a featureless sky with a cloudy one?
Does anyone have a procedure that works?
Is there a plugin for sky swapping?


I've tried the instructions at https://www.mrvicaphotography.com/how-to...-gimp.html .
I claim they don't work.  E.g., selection with the Fuzzy Tool is deranged.  Selection with "by Color" selects on the wrong layer.

[Ofnuts]

It actually depends qui a lot on the picture. Replacing the sky behind trees (lots of little holes, fuzzy borders) and behind buildings (straight, high contrast limits) may require different techniques.

[PixLab]

(04-08-2023, 07:17 PM)Punchcard Wrote: I claim they don't work.  E.g., selection with the Fuzzy Tool is deranged.  Selection with "by Color" selects on the wrong layer.

You can claim whatever you want, the tools are working perfectly, it does not select the the wrong layer... until you tell it to "Sample merged" => which is a mix between ALL visible layers, or your "Select by" is on the wrong mode.

   

Also the tuto you've found is not a good one, as a rule of thumb, when a tuto start by "Gimp doesn’t have all the tools Photoshop does"(*), it means those people does not have even a slight idea about what GIMP can do, thus just go away from those.

Proof, I do exactly in GIMP what he said GIMP cannot.
a 40-second video > https://imgur.com/onIqa4u

(*) This is true, but you can say that GIMP has some tools that Photoshop does not have

[sallyanne]

How can I replace a featureless sky with a cloudy one? First make sure your picture has an alpha channel
Best way would be to select the sky area manually (with the path tool, free select, magic wand, quick mask etc. Then delete those selections so you have a transparent area where the sky is.
Does anyone have a procedure that works?
Open as a layer a cloudy sky once you find it - making sure it is of similar size and put it behind the picture. Should show through your tranparent areas.
Is there a plugin for sky swapping?
You may need ai for sky swapping

[rich2005]

@Punchard

Gimp has a learning curve same as anything else. Do not blame Gimp until all user error is ruled out.

As ofnuts said, various techniques. One of them is using luminosity masks. If you search you will find YT videos on the method. I refuse to recommend anything 22 minutes long, shame on you DMD  

However a 40 second demo: https://i.imgur.com/kjxNF9I.mp4 with a typical blown-out sky.
Some preliminaries, I added a sky layer, sized to fit. Using the old saulgood script. A little tidy up at the end using Dilate on the layer mask.

Not going to work with every image, up to you to experiment.

I case interested, the script attached. It is old, but it works well. There are more up-to-date versions.