This is a TransferFunction object that maps from non-linear display signal RGB to itself.
It maps from the full range [0,1] to the
smaller range [ 64/1023, 940/1023 ] \(\approx\) [ 0.06256109, 0.9188661 ].
The latter is the 10-bit "legal-SMPTE"" range.
It does this in an affine way, and in fact simply uses affine.TF().