[Openicc] beyond 8-bit precission [was: new version of xcalib]

[Kai-Uwe Behrmann]

Am 07.03.05, 13:14 +1100 schrieb Graeme Gill:

> But that is not actually a major limitation, if you are careful
> in your color configuration. The input end (8 bit per component)
> is a colorspace with a transfer curve that you are defining with
> the RAMDAC values. It's therefore possible to choose the values
> of your 256 steps so that each step is visually imperceptible.

Seems not possible. I can do what I want 8bit steps are allways visible on 
my LCD (average model). An synthetic gradient shows clearly what I mean. 
No black/white photographer is convinced by an maximum of 8-bit level of 
sensitivity. In medical practice 8bit is not used for the same reason 
(X-ray images).

> (i.e. back of the envelope calculation shows that a 0 to 100 L*
> range divided equally into 256 steps gives steps of 0.39 delta E,
> less than half of the perceptible threshold.)

This calculation refers to an reflective media, right?
Todays inkjets have left behind 256 steps - steps in the sense of 
stepping. Tell me if you like, I can send you an print, which shows 
clearly each step of 8-bit shades of gray output.

Todays artists need more precission!

 for photographs, for film and on screen.
 Not for offset, not for avarage consumers (today), not for popart ;)

regards
Kai-Uwe Behrmann
                                + development for color management 
                                + imaging / panoramas
                                + email: ku.b at gmx.de
                                + http://www.behrmann.name