Am 12.03.2013 17:44, schrieb Richard Hughes:
wondering how we should be doing this using wayland / weston. I appreciate we'll be doing the advanced sRGB->native gamut mapping as some kind of sub-surface, but this device calibration state is orthogonal to that. Most existing display ICC profiles encode a
*Additional* instead of *orthogonal* would be more precise, as the advanced calibration gamma curve adds to the ICC profile's internal gamma curve. Additional means in this context, the Xorg calibration curve reduces tonal range in a 8-bit per channel pixel pipeline, as it operates entirely in 8-bit precission. While a ICC colour transform can be applied to 16-bit data and then sent as 8-bit using all available bits and avoid banding artefacts.
calibration RGB gamma ramp in them (the 'vcgt' tag) and the profile is not valid unless the device matches the calibration state.
Sad, but true. Better are ICC profiles, which omit the vcgt tag alltogether. That is much more straight forward IMO.
kind regards Kai-Uwe _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
