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

in out in in in in in in out out inWhite balancing is performed using a mapping that maps the visible gamut's boundary into itself. A predefined color Wis mapped into a color Wwhich is a white color or a color perceived as white under some viewing conditions. If Sis some other color, a corresponding color Pis determined on the visible gamut's boundary. Pcan be on the intersection of the visible gamut's boundary with a plane containing Sand Win a linear color coordinate system. Sis mapped into a color Sobtained from Wand a value of the mapping on P.