Gradient to color levels

[Alp_Alton]

Hello

Is there any way to convert a gradient area to layers or levels of fewer colors like sample picture?

Thank you

[Blighty]

Your request is a little short on details.

I presume the image you attached is the end result. What do you start with? A colour image? Do you have a before and after example? Must the end result be grayscale? (Your image is still RGB)

Your image has 300 colours. Is that what is required?
Do you want each colour on its own layer?

[Alp_Alton]

(08-22-2019, 11:31 AM)Blighty Wrote: Your request is a little short on details.

I presume the image you attached is the end result. What do you start with? A colour image? Do you have a before and after example? Must the end result be grayscale? (Your image is still RGB)

Your image has 300 colours. Is that what is required?
Do you want each colour on its own layer?

Thank you for your reply
Yes that image was  just a sample I got from net and starting would be by creating simple gradient image using GIMP.
Color is not important, gray scale or scales of other colors; but if I have to work on 256 gray scale or even lesser indexed colors, still solves my problem.
What I need is converting gradient colored area of an image to stepped or leveled gradient (several close values rounded) like the attached images as before and after.
Sorry, I think I shouldn't use word "layer". Whole thing will be on one layer.

[rich2005]

Maybe something like this:. Depends on the starting point but you can use RGB

(1) Colors -> Posterize will reduce the number of RGB colours  or Greyscale shades

and

(2) If RGB then Colors -> Desaturate -> Desaturate reduces to grey & the image is still RGB

or  Image -> Mode -> Greyscale will give an 8 bit image.