Re: [gentoo-user] Does Gentoo support more than 8 bits per color channel?

[wabe]

Helmut Jarausch  wrote:

> Hi,
> I'm considering buying a new monitor (and graphics card) which
> supports 10 bits per color channel.
> Will Gimp on a Linux machine (X11) support this now or in the near
> future. Or is it just waste of money to buy a monitor with more than
> 8 bits/color channel? Many thanks for some hints,
> Helmut

I have two identical machines. GPU is Radeon R7 250E and Monitor is
a Samsung U32D970. Monitor and GPU both supporting 10bpc. One machine 
is running Gentoo and the other Win7.

When I start Radeon Settings on the Win machine, it shows me that 
10bpc are used. All graphic software that I use on the win machine 
also supports 10bpc.

On the gentoo machine I use xf86-video-ati-7.10.0 and 
xorg-server-1.19.5. When I look at /var/log/Xorg.0.log I can see that
only 8bpc are used. 

At the time when I bought my monitor (nearly 3 years ago) I searched
the internet for information about Linux and 10bpc. All I found was 
that it is not supported by the xorg drivers. As I do no graphic work 
on gentoo this is not that important for me. So I never searched again.
Maybe it is supported now but I didn't read anything about that on the
xorg-announce mailing list so I don't think so.

Maybe other drivers (nvidia or proprietary amd) are supporting 10bpc.
But I never searched for that information.

Although the newest Gimp supports 16 and 32 bit images and also can 
use these color depths on internal rendering, I don't know if Gimp 
could support more than 8bpc color output if the display would be able 
to. 

--
Regards
wabe

Re: [gentoo-user] Does Gentoo support more than 8 bits per color channel?

[Andrew Savchenko]

On Fri, 20 Oct 2017 16:17:37 - Helmut Jarausch wrote:
> Hi,
> I'm considering buying a new monitor (and graphics card) which supports
> 10 bits per color channel.
> Will Gimp on a Linux machine (X11) support this now or in the near future.
> Or is it just waste of money to buy a monitor with more than 8 bits/color 
> channel?
> Many thanks for some hints,
> Helmut

Linux and Gentoo in particular supports 10 and 12 bits per channel.

But in order for this to work you need to have support from all
chain, both hardware and software:

application -> de/wm or rendering stack (gtk/qt) -> xorg (supports)
-> video driver (see below) -> video card -> cable(! ) -> monitor

You have not told us what is your video card, but at least Intel[1]
and nVidia[2] products support 10/12 bits in Linux.

Definitely not all application support deep colour (10/12 bpc), but
most multimedia oriented do: gimp, ffmpeg, mplayer, mpv...

You may encounter some problems with GTK apps, though the proof
links I found[3,4] are quite old and situation may have improved.

Also take a note that 10 bpc imposes some limitations on the screen
resolution depending on your connectivity[5].

[1] https://communities.intel.com/thread/101627
[2] 
https://nvidia.custhelp.com/app/answers/detail/a_id/3050/~/how-to-enable-30-bit-color-on-linux
[3] http://www.oyranos.org/tag/30-bit/
[4] http://darktable-users.narkive.com/ndONjycG/anyone-with-30-bit-color-depth
[5] http://bilder.hifi-forum.de/medium/262100/hdmi-20-597x266_609346.jpg

Best regards,
Andrew Savchenko


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Re: [gentoo-user] Does Gentoo support more than 8 bits per color channel?

[Floyd Anderson]

On Fri, 20 Oct 2017 22:05:27 +
mad.scientist.at.la...@tutanota.com wrote:
Linux will support at least 24 bit color on cards it can drive (nearly 
anything current).


Look at the subject, Helmut ask for Deep Color (30/36/48-bit) [1] not 
for True Color (24-bit).



[1] 



--
Regards,
floyd

Re: [gentoo-user] Does Gentoo support more than 8 bits per color channel?

[R0b0t1]

Hello,

On Fri, Oct 20, 2017 at 11:17 AM, Helmut Jarausch  wrote:
> Hi,
> I'm considering buying a new monitor (and graphics card) which supports
> 10 bits per color channel.
> Will Gimp on a Linux machine (X11) support this now or in the near future.
> Or is it just waste of money to buy a monitor with more than 8 bits/color 
> channel?
> Many thanks for some hints,
> Helmut
>

It is my understanding the software itself needs to support this. It
is rare enough that I do not know how it is done in practice, but,
generally, it would be necessary to specify relative colors or colors
by name and leave implementation up to a layer that translates the
color spaces.

This would be similar to what has to happen for high DPI displays. If
a program is not aware that pixels can be different sizes, it will not
make use of the extra resolution properly.

High end graphics cards have implemented features related to what you
are asking about. Some support transformations that happen directly on
the tuples that represent the color model of the human eye, or the
model of the reflectivity of pigments used in printing. I have yet to
see any programs which actually use these features.

Checking the Wiki, "deep color" capable graphics cards have existed
since the 1990s. Also at
https://en.wikipedia.org/wiki/Color_depth#Deep_color_.2830.2F36.2F48-bit.29
are compatibility notes that seem to indicate that color depth is
mediated by the graphics card and screen. It is up to the program to
ask for colors of that depth to be displayed.


Short answer: Open bug reports on the trackers for the programs you
are interested in.

Cheers,
 R0b0t1.

Re: [gentoo-user] Does Gentoo support more than 8 bits per color channel?

[mad.scientist.at.large]

Linux will support at least 24 bit color on cards it can drive (nearly anything 
current).  It would help to know which graphics card you are looking at.  last 
time i saw 8 bit color was decades ago.  you should also look it up using your' 
favorite search engine, often very usefull and samples a larger pool of 
information than any one email list can.

mad.scientist.at.large (a good madscientist)
--
I find it ironic that at a time when Americans are concerned about violence and 
 Bullying in schools  and elsewhere that we would elect a Grand Poohbah who's a 
violent bully and hates everyone, including himself, as demonstrated by speech 
and action.  I've known 2 year olds that behaved more appropriately.  Besides, 
there can be no rule of law when those in charge are contemptuous of the whole 
frame work on which our country is based .


20. Oct 2017 10:17 by jarau...@skynet.be:


> Hi,
> I'm considering buying a new monitor (and graphics card) which supports
> 10 bits per color channel.
> Will Gimp on a Linux machine (X11) support this now or in the near future.
> Or is it just waste of money to buy a monitor with more than 8 bits/color 
> channel?
> Many thanks for some hints,
> Helmut

[gentoo-user] Does Gentoo support more than 8 bits per color channel?

[Helmut Jarausch]

Hi,
I'm considering buying a new monitor (and graphics card) which supports
10 bits per color channel.
Will Gimp on a Linux machine (X11) support this now or in the near future.
Or is it just waste of money to buy a monitor with more than 8 bits/color 
channel?
Many thanks for some hints,
Helmut