Re: Gamma correction


Jim schrieb:

On 19 Feb., 13:50, Graeme Gill <inva...@xxxxxxxxxxxxxxx> wrote:

Yes, but how are you measuring this ? You can't do it visually,
because we don't see light linearly. In fact, our visual sense
of brightness is almost exactly matched by the standard monitor
gamma power of 2.4, meaning that the monitor gamma distortion makes
a numerically linear ramp appear to be fairly perceptually even.

But if this was the case then why would you need to gamma-correct the
input values before sending them to the monitor?


As long as you're not working in a color managed environment,
you can use any linear or nonlinear coding for your gradient
pattern.

So far, the 'correc't grayscale by appearance is nowhere defined.
But the correct grayscale by measurable luminance is defined.

Color management tries to map scene luminance to visual
luminance as good as possible. Essentially, this is a linear
mapping (e.g. for a scanner or a digital camera) .
There are really big difficulties, concerning the compression
of the dynamical range, but this has nothing to do with the
trivial power function by Gamma.

Best regards --Gernot Hoffmann

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