Extract creator function
# S3 method for pth_cam02ucs
pth_creator(mat, ...)
# S3 method for pth_cam16ucs
pth_creator(mat, ...)
# S3 method for pth_cielab
pth_creator(mat, ...)
# S3 method for pth_cieluv
pth_creator(mat, ...)
pth_creator(mat, ...)
# S3 method for default
pth_creator(mat, ...)
# S3 method for pth_jzazbz100
pth_creator(mat, ...)
matrix with object with S3 class pth_mat
other args, not used
function
that encapsulates a creator, i.e. pth_new_cieluv