Histogram required for float-point version.

[rageworx]

Floating point version not works correctly, histogram windowing.
Need to make it back to work.

[rageworx]

Histogram + windowing result too much dithered, strange.

[rageworx]

Floating point version is not ranged, actually too many variations 0.0 to 1.0.
Just need compression width or, maximum value of floating point to integer casting, maybe.