A linear system form solution to compute the local space average color
In this document, we present an alternative to the method introduced by Ebner (Pattern Recognit 6067, 2003; J Parallel Distrib Comput 64(1):7988, 2004; Color constancy using local color shifts, pp 276287, 2004; Color Constancy, 2007; Mach Vis Appl 20(5):283301, 2009) for computing the local space average color. We show that when the problem is framed as a linear system and the resulting series is solved, there is a solution based on LU decomposition that reduces the computing time by at least an order of magnitude.
local space average color color constancy gray-world assumption