White balancing that uses values of white-balanced colors on the visible gamut's boundary

摘要

White balancing is performed using a mapping that maps the visible gamut's boundary into itself. A predefined color W_in is mapped into a color W_out which is a white color or a color perceived as white under some viewing conditions. If S_in is some other color, a corresponding color P_in is determined on the visible gamut's boundary. P_in can be on the intersection of the visible gamut's boundary with a plane containing S_in and W_in in a linear color coordinate system. S_in is mapped into a color S_out obtained from W_out and a value of the mapping on P_in.