color calibration and xvideo (xv)

[Marco]

Friedrich Schiller escreveu:
> Many thanks again!
> 
>> Is there something like that? If you pick the window with movie and move it
>> around quickly, you should see the colorkey behind the movie (in the case of
>> Radeon, it is usualy pink, the XV_COLORKEY says RGB value of the colorkey).
> 
> Yes, I do see the pink colorkey when I move the video lan client
> very quickly.  So I guess the LUT is indeed by-passed.
> 
> 
>> the problem here could be that ICCM profile cannot be applied to XV overlays.
>> You can basically change gamma/brightness/saturation and so on but you cannot
>> apply the profile obtained somewhere somehow. And I guess this is probably the
>> reason for the initial question.
> 
> Yes.  Setting the three standard monitor parameters (Gamma, black
> point, white point) allows only for very limited color correction.
> In contrast, using the LUT provides a much more fine grained map between 
> internal color representation and actual color output.
> 
> 
> As a matter of fact, I would have never believed myself that proper 
> color calibration makes such a difference, i.e. until I borrowed a friend's
> colorimeter and used "argyll" to create a monitor profile.
> The difference is really like day and night!  For instance,
> I always thought my digital camera has a tendency to produce "foggy"
> picures - but in fact the colors are spot on and it was only a problem
> of setting the proper color management in X11 ...
> (see also http://en.wikipedia.org/wiki/Linux_color_management ).
> And now when I watch a DVD (through color corrected X11) I almost
> also can't believe how much richer and balanced the colors are ...
> 
> So it is good to see that there is awareness of this issue!
> 
> Best regards,
> 
> Freddy
Do you have a tutorial about this calibration?

-- 
Marco de Freitas,
NBR para a Internet já! Porque meu navegador não é penico.

http://www.softwarelivre.org/news/2472
http://www.w3.org/2003/03/Translations/byLanguage?language=pt-br