exposure:this is here for convenience, so we save the memory bandwidth to carry  all the pixels to yet another module doing a trivial transform on the input data.
mode:the module can be run in :parametric:mode, where the colour matrix and white  balance coefficients are used and then the RBF only comes into play for gamut mapping.  the :data driven:mode works on an aribtrary list of source and target points which  can be given in the parameters as :source:and :target:list of points.  this parameter runs a ui group, so it will show/hide a few other elements.
gamut:the gamut can be left untouched, projected to spectral locus, rec2020, or rec709.
