In article <45b8f419$1@news.povray.org>, nicolas$george@salle-s.org 
says...
> Patrick Elliott  wrote in message
> <MPG.201c800845c4c970989fd5@news.povray.org>:
> > Umm. Ok... But, from a purely practical standpoint, even if changing th
e 
> > effect, you get clipping, instead of correctly adjusted colors. Its lik
e 
> > adjusting the volume of a raw audio file format, instead of turning up
 
> > your speakers. If "any" part of the sound is low enough to fall below a
 
> > certain threshold and you adjust down, or it goes above a certain 
> > threshold and you adjust up... it ends up eating part of the *actually*
 
> > waveform. Same with Gamma and software based solutions to it. That is
 
> > what I was getting at.
> 
> You are wrong. As someone already pointed, the gamma does not affect the
> black and white points. It is a one-to-one mapping between the minimum an
d
> maximum intensity level. It stretches the dark values, and compresses the
> light ones, but there is no clipping whatsoever.
> 
> What there is, on the other hand, is loss of precision in the part that g
ets
> compressed. For a gamma of 2.2, for example, value 0.5 becomes 0.73, whic
h
> means that, on the discrete scale, the two lower bits of the light colors
> are lost.
> 
Sigh.. How about "blending" or "blurring" then, since the problem is 
that, basically, if you have a fine gradient that you "need" to have 
stay that way for the detail to be obvious, its going to screw things 
up. You lose data "period". It doesn't matter if it "technically" isn't 
messing up the white or black points, if it never the less has the 
unfortunate side effect of making it "look" like its doing so, by losing 
colors that *should* remain the same, just brighter or darker. Its what 
the perception is, not what may or may not actually be happening. And in 
90% of cases, people attempt to use Gamma to correct for how "bright" 
the image is, not if green looks 0.01% more blue on Fred's display than 
on Ralph's.

-- 
void main () {

    call functional_code()
  else
    call crash_windows();
}

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