[OpenICC] Oyranos - proof of concept

[Kai-Uwe Behrmann]

Am 22.04.05, 15:12 -0400 schrieb Jim Gettys:

> On Fri, 2005-04-22 at 21:08 +0200, Kai-Uwe Behrmann wrote:
> > Am 22.04.05, 11:28 -0400 schrieb Jim Gettys:
> > 
> > > > To X:
> > > > I think we can extend to realtime colour configuration for X . It 
> > > > is ok to connect to D-Bus through a X dedicated library - liboyranos-moni.
> > > > How can X / Oyranos transport the monitor profile information 
> > > > networktransparently  (Craigs question?) Similiar to DDC?
> > > > 
> > > 
> > > Arguably, unless the monitor profile information is huge, I'd recommend
> > > making it a property on the root window of each screen, that
> > 
> > Profile sizes varies from 1kB up to ~400kB depending if the 
> > information is stored as matrix or as CLUT.
> 
> And what is a typical size?  400kB is large, but these days, it isn't as
> huge as it might have been in the past...

The smaller matrix profiles are prefered by current CMS's. They are about 
1-6kB. But I expect the CLUT become desireable for modern LCD's. Please 
can one of the profiling experts correct me if I am wrong here.

> > 
> > > applications can retrieve.  What is more, applications can get
> > > notification of changes to window properties, which would enable this to
> > 
> > What does X use for notification?
> > 
> 
> You select for PropertyNotify, and get notified by the X server with an
> event whenever the property is changed.  This is how, for example,
> applications get told that their keyboard mapping has changed.

So Oyranos could attach its information to a Xproperty and some 
listeners can be notified by X. 
This approach can be utilised for other Oyranos APIs as well.

> > > be handled pretty easily in a cross toolkit fashion.  I think this is
> > > roughly what was done in the past in the ill fated attempts at building
> > > a CMS into Xlib.  And it means you can get started without any X server
> > > infrastructure changes; your program can load such properties on its
> > > own.
> > 
> > That seems reasonable.
> > 
> > > D-bus comes into play in telling the X server what is going on; after
> > > all, changing a monitor has other repercussions that the X server may
> > > need to know about directly.
> > 
> > Yes, I think less handling of hardware issues is better for Oyranos. If 
> > Oyranos can get a signal from X about changes, update the monitor 
> > information if appropriate and then signals to its own listeners that 
> > would suffice. 
> > Even though notification is not really possible now in Oyranos. 
> > 
> 
> Regards,
> 			- Jim
> 
> 

regards
Kai-Uwe Behrmann
                                + development for color management 
                                + imaging / panoramas
                                + email: ku.b at gmx.de
                                + http://www.behrmann.name