-fx_slice_luminosity

I was trying out various filters when I came across -fx_slice_luminosity in GIMP.

At first glance, I assumed that each activated slice would generate a separate layer, similar to what split details or luminosity masks scripts would do. Instead, it generates two layers: a duplicate of the base layer and a layer that is the sum of all the activated slices. Is that the expected behavior?

I would find utility in the inclusion of an option to output a layer per slice; and perhaps in having more than 4 slices, but that would add more arguments to this monstrosity:

-fx_slice_luminosity 1,1,2,1,0,64,0,0,1,64,128,0,0,0,128,192,0,0,0,192,255,0,0

I don’t know about that :sweat_smile:.

Yes, this is the intended behavior.
The N-1 first images produced by this filter have an alpha-channel, and the last one is the original image, so that when the layers are merged together you see the original picture.
I’m not sure this filter has any interest to be used with the command line interface though :), as it has been specifically designed to produce something that is natural to use within an image retouching software (such as GIMP).