// The definition (in xyz space) is given, for instance, in both Rec. 601 and 709.
static const double d65_x = 0.3127, d65_y = 0.3290, d65_z = 1.0 - d65_x - d65_y;
+// XYZ coordinates of D65, normalized so that Y=1.
+static const double d65_X = d65_x / d65_y;
+static const double d65_Y = 1.0;
+static const double d65_Z = d65_z / d65_y;
+
#endif // !defined(_D65_H)