Reproduce Color Adjustments from One Image to Another?

[Ofnuts]

You can do that with a CLUT (Color Lookup Table) which is a way to describe the mapping between input colors and output colors. Such a map should in theory be 16MPix, but you can in practice do with somewhat less (64 values per channel is fairly common).


With the GMIC filter suite:

On the initial image:

• You load the before/after images as layers in the same image
  
• In GMIC you use the Colors >  CLUT from After- Before layers to generate the CLUT (save to file)
  

On other images:

• In GMIC you use Colors > Apply external CLUT and specify the saved CLUT image
  

This of course assumes that you only did color adjustments, in other words, that the value of a given pixel on the result only depends on the initial value of that very same pixel and not on its neighbors (no sharpening, etc...).