On Mon, Feb 4, 2013 at 7:43 PM, Pascal Obry <[email protected]> wrote: > Pascal, > >> I seriously doubt that. >> >> I guess it's probably not configurable to be anything else than the >> system configured profile, thus no settings are visible on this topic. > > That's what I mean. From a user point of view there is no way to select > a display profile. Internally I just don't know.
Right. I sort-of appreciate the "just works" mentality. But it also breeds to problems: 1. user ignorance 2. it complicates troubleshooting We just default to "system display profile" so users typically never need to change this setting, except to troubleshoot potential problems. >> Double correction cannot happen (well unless you have a really highend >> LaCie/EIZO display which can do hardware correction or something). > > You're probably 100% correct. But my question was more: what is the > usage for the darktable display profile? Is that supposed to be used to > activate calibration in darktable when there is no profile at the system > level (using GNOME Color Manager for exmaple)? Or is it for something else? Well, as I llustrate in my article, there are two parts to a profile the vcgt and the matrix+shaper (please see my article* for details). GNOME Color Manager sets up a display profile in colord (which is a desktop agnostic infrastructure daemon, which does nothing by itself). On login GNOME Settings Daemon queries colord what profile to setup for the display. When colord tells GNOME Settings Daemon to setup a display profile two things happen: 1. The profiles vcgt is loaded into X11, which is transparently applied by X11 and thus benefits all programs running on X. 2. The profile file (the .icc) is loaded into an X atom (_ICC_PROFILE). Applications like Darktable, GIMP (if enabled), etc read this X atom so they can extract the matrix+shaper to apply to the imagery they want to display in a color managed fashion. There is however an extra complication with dual screen setups, since there is only one X atom that is read by applications only a single display can be fully color managed and the other display is even likely to have the wrong profile applied with many applications. To fix this Darktable (as one of the first) implements colord support, so we directly query colord which profile to use. I think we even have detection on which display darktable placed, and it can even switch profiles when darktable is moved between displays (assuming you have colord properly setup). I don't have a dual display setup myself, so I never tested this. Since not everybody has/wants colord, we do the following 1. check colord if a display profile for the display darktable is placed on is available 2. check if the _ICC_PROFILE atom is available 3. use sRGB if both the above fail. Regards, Pascal de Bruijn * http://blog.pcode.nl/2012/01/29/color-management-on-linux/ ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_jan _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
