The whole point of these formats is to compress down to less
space, so let's not leave actually putting it in the space-saving
form on the client code.
It is identical to the 32-bit format, except with more precision
and range due to using more bits. This format should comfortably
store any color information with precision easily exceeding the
limits of human vision.
It was a worthwhile experiment, but for it to really work it needs
a really proper luma-chroma separation, which is both slower than
I really want, and requires knowing the colorspace being used.
I might make another go at this based on the TIFF LogLUV color
format, requiring XYZ as input.
