Originally Posted by Benny Profane
It's just a term in image processing that refers to reproducing something in a set of discrete steps. It's a slightly odd term to use there, because it comes from signal reconstruction where you have to fit a finite set of points to a continuous change in voltage. In this case we were referring to errors in assigning a discrete set of values to a given mapping, even though it didn't explicitly refer to signal reconstruction. It's still similar when you convert between color spaces, as it's done most commonly via linear transformation. It sounds like something weird, but it just means that they're only dealing with multiples of the original values. The new ones aren't dependent on the squares or higher powers of the old ones, which makes it a bit simpler.