Investigation of white standards by means of bidirectional reflection distribution function and integrating sphere methods.

The paper deals with investigation of the white Lambertian standards by means of optical methods, i.e., the bidirectional reflection distribution function (BRDF) method and the reflectance study with an integrating sphere. All measurements have been made using the L*a*b* color system. The effect of the choice of a standard on values of trichromatic parameters and the effect of aging of standards is discussed. [ABSTRACT FROM AUTHOR]