Re: [gentoo-user] CMYK comparison to sRGB between platforms

[Mick <michaelkintzios@gmail.com>]

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On Tuesday 08 Sep 2015 23:49:21 wraeth wrote:
> On 09/09/15 04:42, Mick wrote:
> > On the same hardware I noticed that a CMYK photograph converted to
> > sRGB looked mostly the same (indistinguishable) on Linux, but the
> > sRGB colours were brighter on MSWindows.
> > 
> > I tried this by dual booting between MSWindows and Linux.
> > 
> > Then I tried it by running MSWindows within a VM on a Linux host
> > and the MSWindows showed a clear difference in brightness between
> > the two formats.
> > 
> > Finally, I checked on an AppleMac and the difference between the
> > CMYK and sRGB photographs was even more prominent than MSWindows.
> > 
> > So, the Linux renedering seems to be misleading the user.  Have you
> > noticed the same?
> > 
> > BTW, both Linux machines that I tried this on are running radeon
> > drivers - are these to blame?  The AppleMac is running Intel
> > graphics with its 'retina' monitor.  Is it a matter of somehow
> > tuning the Xorg settings on my Linux PCs?
> 
> While I'm certainly not an expert on this sort of thing, one key piece
> of information that would affect this is what software you used.
> Specifically, did you use the same software on each platform
> (therefore the same method of conversion)?

The conversion from CMYK to sRGB was performed on Linux.  The user 
experimented with different CMYK.icc and sRGB.icc files using imagemagick and 
also Gimp.  Then the original CMYK and resultant sRGB files were moved around 
different PCs and OS and their difference observed.  The difference was more 
prominent in a MacBook Pro, next (almost equally) visible in MSWindows 7 
either run natively or in a VM and finally least visible difference (you had 
to squint to see it) was in the Linux PCs.

The only common thing between the Linux PCs was that they are both running 
Gentoo but have different radeon cards & different firmware.

-- 
Regards,
Mick

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