| From: | Ben Hutchings |
| Date: | 01 Dec 99 at 23:49:55 |
| Subject: | Re: Little maths problem |
From: Ben Hutchings <womble@zzumbouk.demon.co.uk>
On Thu, Dec 02, 1999 at 09:02:08AM +1100, Jonathan wrote:
> From: "Jonathan" <jadamcze@utas.edu.au>
>
>
>
> | From: "Alastair M. Robinson" <blackfive@fakenhamweb.co.uk>
> | You might also want to experiment with the gamma function (as found in
> | your favourite image processing program):
> |
> | f=exp(gamma*(log(f)-log(500000.0)));
> |
> | If gamma is set to 1.0, you'll get a linear transfer. Set it lower than
> | 1.0 to bias in the direction you want, and higher than 1.0 to bias in the
> | other direction.
> |
>
> How does gamma work? (never seen it before)
gamma is the usual letter representing this `non-linearity' value in a
response curve. gamma values are normally quoted for optical input or
output devices, or for some processing/filtering of optical signals.