Is there a way to automatically extract colors? for gradient map

[Jqqerry]

Is there a way to extract automatically like the title?

Of course, it's best to manually extract the desired color point based on the brightness...

I thought it would be more convenient if there was a way to limit the number of patches on the gradient map and apply them automatically.

I can extract palettes using index plus color tables in Photoshop, but it's complicated to apply them to the gradient map.
I think there's a way to select certain parts and feed them with average blur like something, but I don't know the solution.

What do you think?

[Mylenium]

This would require quite a bit of scripting due to different functions and features being involved across the board. As far as I know there is no straightforward, intuitive way to do this. Figuring out the color math for perceptive colors alone could be complex.

Mylenium