> No it's not: it may as well be that the function applied to the perceived colours, while takes neighbours as an input - still outputs the same 256^3 colours.

> No it's not: it may as well be that the function applied to the perceived colours, while takes neighbours as an input - still outputs the same 256^3 colours. Kinda like those post-processing shader effects (like blur etc) that look at neighbouring pixels to output a 256^3 colour value for the center pixel. The pixel value never leaves the 256^3 range, but its value is adjusted based on what surrounds it.