ls = LMSToMacBoyn(LMS,[T_cones,T_lum])
Compute MacLeod-Boynton chromaticity from
If T_cones and T_lum are not passed, we assume
Smith-Pokorny sensitivities normalized to a
peak of 1. I T_cones and T_lum are passed,
we compute the scalings of the L and M cones
required to best predict lumiance and scale
10/30/97 dhb Wrote it.
7/9/02 dhb T_cones_sp -> T_cones on line 20. Thanks to Eiji Kimura.