Replacing over exposed sky in a photo

[gazza]

I am trying to replace the "Wishy Washy" sky in the attached photo. Unfortuately I cannot download a better photo, but the grasses and the rock are great colours but the sky is overexposed. Could someone please point me in direction of a method of the correct way to do this.  I have tried a few methods in You Tube but with not very much success. 
Many Thanks
Gary

[Ofnuts]

Is this the photo you want to fix? Because it is heavily over-processed already....

Otherwise:

• with the Color select tool, click in the sky to select the white. This will select all the sky, including the bits between the grass blades.. This will also select bits of white the the grass which is why you
  
• enter "quick mask" and paint in black over any parts of the foreground that look selected (not marked with red, so these bits should appear as white).
  
• make sure you have an alpha-channel (Layer ➤ Transparency ➤ Add alpha channel) and Edit ➤ Clear or [delete] to make the sky transparent (yes, this leaves a visible border along the rocks on the right, we comes to that later)
  
• add your sky layer, and move it under the image (I used a plasma, colorized, there are plenty of other ways)
  
• with the Eraser and a soft brush, erase the white edge along the rocks
  

   

[PixLab]

(05-29-2023, 04:26 AM)gazza Wrote: Unfortuately I cannot download a better photo, but the grasses and the rock are great colours but the sky is overexposed.
Gary

We do not have the same definition of "great colours", I mean did you check the picture you did upload? It's "B&W" with plenty colored artifacts

To replace a sky, many way to do it (might have been better to have the original),
below 3 different methods
1) Colors > Color to Alpha with a blue sky underneath the layer you're using the color to alpha

2) duplicate and use the duplicate to make a mask by darkening the darks and whiten the whites whith Colors > Levels / Curves or Duplicate and Threshold (Colors > Threshold), then use the mask on your main photo to let a layer with a beautiful sky underneath appear, blur / sharpen the mask to smooth or shapen the edges

3) a quick third method that I hate but beginners love, put underneath a blue sky, then select the white part of the sky and delete it,
then to fine tune: Alpha to Selection > Select > Feather... to fine tune the smoothing selection gradient then hit the delete key (Ctrl+Z wil be your friend with this method as it's all trial and error with this method)

In the end, it might have been better to get the original photo, as even more different methods could be done. and maybe no need to remove the sky, just enhancing the original one might even be better

[Ofnuts]

(05-29-2023, 06:35 AM)PixLab Wrote: 3)  a quick third method that I hate but beginners love, put underneath a blue sky, then select the white part of the sky and delete it,

Usually, yes, but it makes sense here since the colors are very quantized (the OP's image could be even more quantized, some of the quantization having been blurred by the JPEG compression).

[rich2005]

As usual with Gimp there is a script.

https://www.gimphelp.org/photo_highlights_to_sky.html

   

[gazza]

Thanks everyone for the ideas, I will work on it. Unfortunately I could not send the original photo. I tried to minimise it using my "Compress Jpeg" app, but  couldn't get it to 500kb. 
Gary

---

Thanks for your input Rich2005 ........worked perfectly!!!!!!!!!!!

[PixLab]

(05-29-2023, 06:28 PM)gazza Wrote: Thanks everyone for the ideas, I will work on it. Unfortunately I could not send the original photo. I tried to minimise it using my "Compress Jpeg" app, but  couldn't get it to 500kb. 
Gary

You can could just scale down the picture, something like 2000x1332 pixels or even smaller like 1500 wide

[PixLab]

(05-29-2023, 07:14 AM)Ofnuts Wrote:

(05-29-2023, 06:35 AM)PixLab Wrote: 3)  a quick third method that I hate but beginners love, put underneath a blue sky, then select the white part of the sky and delete it,

Usually, yes, but it makes sense here since the colors are very quantized (the OP's image could be even more quantized, some of the quantization having been blurred by the JPEG compression).

Indeed, you're right, but still it was painful for me to write this third solution

[gazza]

(05-29-2023, 06:28 PM)gazza Wrote: Thanks everyone for the ideas, I will work on it. Unfortunately I could not send the original photo. I tried to minimise it using my "Compress Jpeg" app, but  couldn't get it to 500kb. 
Gary

---

Thanks for your input Rich2005 ........worked perfectly!!!!!!!!!!!

Hi Rich
Question
The method you sent me on how to replace the sky in an over exposed photo does work a treat. However, sometime I get a very thin line around the subject in the photo where the sky does not seem to cut neatly around it. Sort of an abberation look if I am correct in saying that?
I have attached two snips. One shows a white line and the one around the rock is blue?
Regards
Gary

[rich2005]

(06-23-2023, 01:46 AM)gazza Wrote: ...snip...However, sometime I get a very thin line around the subject in the photo where the sky does not seem to cut neatly around it. Sort of an abberation look if I am correct in saying that?   I have attached two snips. One shows a white line and the one around the rock is blue?  

Edit forgot it was about that old script
It is the the script, makes the initial selection, leaves a border of semi-transparent pixels which show up with the replacement sky.

You can try adjusting the script feather amount value. 
You can try editing the layer mask(s) Filters -> Generic -> erode (or dilate)

a quick example, https://i.imgur.com/AorvMDN.mp4 adjusting the script then using dilate to 'grow' the white part of the mask(s) ...but it all depends on your images and you might need to use a more 'hands-on' method