[Openicc] VMs and display correcotions

[Chris Murphy]

On Mar 9, 2011, at 1:53 PM, Graeme Gill wrote:

> Chris Murphy wrote:
> 
>> it's running on. And then for remote display - I haven't even attempted it. I don't
>> know what software is used. Is it typically just another copy of that VM software and a
>> VNC like connection is established?
> 
> There's VNC, and then there's more elegant schemes like X11 and Citrix (which is like
> a Windows version of X11). I don't think any of them are particularly color aware,
> although X11 can work well if the VideoLUT setting is supported by the driver.
> The ICC profile should work remotely since (by convention) it's stored in an Atom.
> (Assuming an application follows the convention!). I haven't played with Citrix,
> so I'm not sure if they have implemented Microsofts color remotely or not.

I have used VNC. When I'm wondering is how host VM applications implement their own remote display feature. For example VirtualBox has an explicit Remote Display feature - and I think the way it works is the host machine runs a guest OS, with Remote Display enabled for that guest. And then some other machine also runs Virtual Box and must somehow be able to access this "published" remote display instance? Or maybe Remote Display in Virtual Box is made available via VNC to any VNC client? Anyway....whatever, VNC clients are definitely not color managed right now. They have no idea what display they are on and have no means of informing the remote OS of the user's display behavior so that display compensation can occur.

Doing display compensation locally is perhaps a little more complicated for the brain to figure out, but maybe not nearly as difficult for the computer. If all of these windows and their context are objects, and all of them simply (haha) forwarded their source space metadata through the remote display stream, it would become the responsibility of either the VNC client (or its host operating system) to color manage those objects locally.

The alternative is a lot of display compensation cycles happening on a server, or the assumption of sRGB and /DeviceRGB neither of which are quality options.


Chris