Re: [Devel] On GRAYS_USE_GAMMA

[Matthijs Melchior]

Billy Biggs wrote:

>  Is something wrong with the list that old posts are getting re-sent?
>
>  -Billy
>  
No, I don't think so, this was my first message on the subject and that
has an incorrect From: address and was queued for approval by the 
moderator..,
apparantly he has done that today!

more at the end....

> Matthijs Melchior (address@hidden):
>
>  
>
> > Hi Billy,
> >
> > Billy Biggs wrote:
> >
> >    
> >
> > > In the freetype source code I discovered GRAYS_USE_GAMMA, which uses a
> > > piecewise linear function to map coverage values onto a rough curve.
> > >
> > > While it's clear that this code is disabled and marked as
> > > experimental, I'd just like to make the request that it not ever be
> > > enabled, as I use those coverage values as alpha values, which are
> > > specified to be linear by everyone I can think of.  My application does
> > > its own gamma correct compositing, and I don't feel like ever rewriting
> > > it to do otherwise.
> > >
> > > Thanks,
> > > -Billy
> > >
> > >
> > >      
> > Well....., I have discovered this GRAYS_USE_GAMMA as well and I am
> > preparing a message to start discussing how to get this enabled in the
> > standard release.  Than a 2 segment linear aproximation to the
> > gamma = 2.4 curve is not good enough, and I will propose a a better
> > solution.
> >
> >    
........

Well, I have read much more about gamma on the net, and I have reverted to
not have X correct the gamma of my monitor any more.  Text looks very good
now, and most picures are OK.

I had to increase the brightness of my monitor quite a bit, from 10
to 60 and decrease the contrast from 60 to 50 (both on a scale 0..100,
whatever these numbers may mean...).  Black is not really black any more,
it is just dark gray now.  I have not found a procedure to calibrate the
settings of the monitor in a context where there is no gamma correction
applied.  Any suggestions for that...? [I now just look at it and see
if it pleases me....]

I am now convinced system wide gamma correction is an unsolved issue,
certainly when anti-aliased text comes into play...

Keith, Billy and Owen, thanks for letting me think more about this.!

--
Regards,
----------------------------------------------------------------  -o)
Matthijs Melchior                                       Maarssen  /\\
address@hidden                                  Netherlands _\_v
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