| From: | Jonathan |
| Date: | 01 Dec 99 at 23:50:41 |
| Subject: | Re: Little maths problem |
From: "Jonathan" <jadamcze@utas.edu.au>
----- Original Message -----
From: Ben Hutchings <womble@zzumbouk.demon.co.uk>
To: <amiga-c@onelist.com>
Sent: Thursday, December 02, 1999 9:49 AM
Subject: [amiga-c] Little maths pr
| 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.
Yep, know all about it ie Quake ;)
So, what is the actual function?