[vtkusers] Lookup tables

[H. Vidal, Jr.]

I am missing something fundamental about lookup tables.

vtkImageMapToColors, according to Docs, produces an output ov unsigned
char. This sounds like an 8-bit output.

But my lookup table has a 16 bit range and 2^16 colors.

So when I tell the ImageMapToColors to use my (correctly built) 16 bit LUT
and try to map 16 bit data, I can ONLY see the data when I set ColorWindow
and ColorLevel for ImageViewer to near-8 bit values.

My data does range (as test pattern data) correctly from 0 to 2^16. But I
think I am only seeing the bottom 8 bits of range.

How does one do this?

What does it mean on vtkImageMapToColors to SetOutputFormatToRGB or RGBA?

If the output is only 8 bits, this suggests that it ONLY works with an
8-to-n bits LUT. I want 16-16 or 16-24 LUT.

What am I missing?

hv