DIN_{99} Lab space is based on DIN 6176: 2001-03, and is derived from L*a*b*
space, and is designed such that a simple Euclidean difference
between two DIN_{99 values has a better correlation with
perceived error than }_{CIE Delta
E 76 (L*a*b* dE). It is generall regarded as equivalent
to }CIE Delta E 94,
but with the advantage that it is a euclidean space and the
calculation is reversible.

Details of white point
configuration.