Balancing colors across images

[jame0123]

Hi there everyone, 

I've got three "blue pencil sketch" images which I've attached. 

I'd like to be able to adjust the blues in all of them to be as close to the same tone as possible. You'll see that I've got an example of a lighter blue, a darker blue, and one that's in between. Ideally I'd like to get all the images to be the same white as well. 

The kicker is that I've got 100 images similar to these I need to do this with, so I need a replicable process for getting all of these to the same-ish blue. 

I had thought perhaps I could do this by creating a color curve preset, but the issue is that the curve needs to be different for every image to get to the final destination. 

What's the right way to do this given that I've got 100 images? I'll compromise a bit on quality for speed purposes here. 

Thanks

[denzjos]

I suggest to convert them to BW and then give them the colour you want. You can use BIMP for batch conversion.
https://www.alessandrofrancesconi.it/projects/bimp/

[denzjos]

(06-11-2024, 06:36 AM)denzjos Wrote: I suggest to convert them to BW and then give them the colour you want. You can use BIMP for batch conversion.
https://www.alessandrofrancesconi.it/projects/bimp/

Also look here : https://www.gimp-forum.net/Thread-Color-...light=bimp

[PixLab]

I would use 1 script sg-combine-bg.scm > https://chiselapp.com/user/saulgoode/rep...combine-bg
and 1 plugin ofn-export-layers.py > https://sourceforge.net/projects/gimp-to...s/scripts/
Once installed restart GIMP

Import all your images as layers File > Open as Layers...

Then add a NEW layer with the color you want them to be, and put that layer in HSL Color mode

(you are not obliged to check with the "Multiply", if you do so DO NOT forget to put those back in Normal mode)
   

Then put that colored layer in "HSL Color" mode at the VERY Bottom of the layer stack and keep the HSL color mode of that layer!
Then go to Filters > Animation > Overlay background (that's the script, it won't ask anything, it just does, look at the status bar when it's finished, should be a matter of a second or 2)

   

Once the script is done, you can delete the colored layer at the bottom of the layers' stack and use the ofn-export-layers by going to File > Export all layers...

Done