🚀 go-pugleaf

Basically I do not understand how colormaps should/can be used.  For a
single band image is it valid to think of them as a lookup table?
What is used if the colormap is OPTIONAL?  For example the kitten
image distributed with Khoros looks the same on an 8 bit SPARC display
whether I use the colormap or not.   Why?

These questions are driven by my desire to include the histogram of
the image as part of a VIFF image.  One technique which comes to mind is
to incorporate the histogram as a color map but I am not sure what the
effect will be.

I also wanted to use a color map to display the relevant portion of
an image so each of my images would have two (optional) colormaps.

Taking an example of what I want to do.
----------------------------------------------------------------------
My 16 bit image has actual data in the gray level region from pixel
value = 10,000 to 12,000. I can make a color map that linearly
maps this [10K,12K] gray level region to 8 bit data for display.  Do I
lose the original data? Can I do this mapping? Waht data does
EDITIMAGE see - the 8 bit or the 16 bit? What happens if I use
the second map (which must be of type LONG or FLOAT) to store the
histogram? I only want 8 bits of data for the display but the "other"
colormap (which is actually a histogram) must be at least 4 bytes/entry.

Thanks.
--
   John C. Schultz   +1 (612) 733-4047   schultz@halley.serc.3m.com
   How to include the taste of Glendronach in a multi-media system?