01-09-2024, 09:47 PM
Two possibilities
Using a CLUT
Looking at two images that only differ by the colors you can construct a "Color Lookup Table" (CLU) that maps every color in an image to the corresponding color in the other. A"full" CLUT maps 16Million colors, (three 8-bit channels), but when you accept some interpolation you can make a CLUT that has entries for only 6 bits (so 262K colors) or 4bit (4096 colors).
When you have obtained the CLUT that goes from one image to anot,er you can apply the same CLUT to all other image in the same theme to produce the images for the other theme. Determining the CLUT is is done with the GMIC plugin. Applying the CLUT en masse is done with the GMIC application (outside of GIMP).
One restriction is that you have to make the CLUT with an image that contains a decent sample of the mapped colors. Colors in another image that are quite different from the ones in the source image run the risk of being strangely interpolated.
Using tiles
If all your images are the same size, you can create a big layer from them, apply the color changes on that big layer, and split the layer back to individual files.. I have scripts for this.
The restriction is that you lose the tile-file association, so you have to maintain this on the side and perhaps rename the files at the end suing a shell script (note that my script allows consistent naming schemes for the output files so it is not as nightmarish as it seems).
Using a CLUT
Looking at two images that only differ by the colors you can construct a "Color Lookup Table" (CLU) that maps every color in an image to the corresponding color in the other. A"full" CLUT maps 16Million colors, (three 8-bit channels), but when you accept some interpolation you can make a CLUT that has entries for only 6 bits (so 262K colors) or 4bit (4096 colors).
When you have obtained the CLUT that goes from one image to anot,er you can apply the same CLUT to all other image in the same theme to produce the images for the other theme. Determining the CLUT is is done with the GMIC plugin. Applying the CLUT en masse is done with the GMIC application (outside of GIMP).
One restriction is that you have to make the CLUT with an image that contains a decent sample of the mapped colors. Colors in another image that are quite different from the ones in the source image run the risk of being strangely interpolated.
Using tiles
If all your images are the same size, you can create a big layer from them, apply the color changes on that big layer, and split the layer back to individual files.. I have scripts for this.
The restriction is that you lose the tile-file association, so you have to maintain this on the side and perhaps rename the files at the end suing a shell script (note that my script allows consistent naming schemes for the output files so it is not as nightmarish as it seems).