How to colorize a greyscale image using a gradient of colors?

[wertoiuy]

I have this greyscale image which I made from a layered colored image. The grey ranges from 26/256 to 121/256. I have made a gradient of colors similar to the colored image. I then want to be able to assign one end of the color range to 26/256 and one end to 121/256. Finally I want to take the greyscale image and convert it to color using that specific graduated color range.

I have the gradient made, but I have no clue how to colorize the gray appropriately.

[Ofnuts]

The first thing to do it to use Levels to extend the range of greys so that the lightest are near white. Otherwise you will have to work with very small gradient segments.

Then you

• create a new gradient (+ icon in the gradients list)
  
• split it into as many segments as you need colors (right click menu)
  
• for each segment you assign a color to the left-hand point (right-click) , and then use Load right endpoint color ➤ From left end point to copy it. This gives a gradient made of bands
  
• then you use Color ➤ Map ➤ Gradient map to apply the gradient
  
• and then Ctrl-Z, move gradients segments limits, and re-run (Ctrl-F) the filter until everything looks rights (rinse and repeat)
  

   

[wertoiuy]

(03-18-2021, 09:19 AM)Ofnuts Wrote: The first thing to do it to use Levels to extend the range of greys so that the lightest are near white. Otherwise you will have to work with very small gradient segments.

Then you

• create a new gradient (+ icon in the gradients list)
  
• split it into as many segments as you need colors (right click menu)
  
• for each segment you assign a color to the left-hand point (right-click) , and then use Load right endpoint color ➤ From left end point to copy it. This gives a gradient made of bands
  
• then you use Color ➤ Map ➤ Gradient map to apply the gradient
  
• and then Ctrl-Z, move gradients segments limits, and re-run (Ctrl-F) the filter until everything looks rights (rinse and repeat)
  

Perhaps I wasn't clear, or didn't understand your description well enough. I have each level in a layer so I could color them separately if I wished. I want the gradient to not be tiered, in order to remove any sort of banding effect. 

I will have to try in an hour or so, but is that also possible using this method?