And if you want to utilize dispcalGUI (v0.2+) to create the profile with the perceptual gamut mapping:
- Under profiling options, select desired quality and type "LUT" - Click "Advanced..." and choose a source profile (working space) - Tick the checkbox "Apply gamut mapping to perceptual table" - Optional: adjust source and target viewing conditions - Close the settings window- Choose "Create profile from measurement data" from the "Extra" menu and select your monitor icc profile (or the .ti3)
Regards, Florian Höch Karl H. Beckers wrote:
-----Ursprüngliche Nachricht----- ..By the way, is this a laptop screen with little adjustment, or a standalone monitor? If you're specifying a target brightness or white-point when calibrating the monitor, are you using the monitor's controls to get close to those targets before running the calibration?It's a laptop and I haven't used the backlight controls for various reasons (hot-key issues with the nvidia drivers for one).I ask because the LUT data is making a pretty heavy white-point adjustment, which may not be helping.Hmm OK, I'll rerun and leave brightness and whitepoint at their native values. If that's any better, I can still try again with the backlight turned low, a bit. Then I'll try your other suggestion with the gamut-mapped profile, though it all sounds like my hopes of using my (not sooo bad) laptop, when my two old Sony OEM CRTs turned out to be just too dim, have been defeated and I need some new displays ... Bummer. Thanks, Karl.Nikolay Pokhilchenko wrote:The other thing you can do is create a gamut-mapped perceptual table for the regular display profile.The result will be image with minimum detail clipping and maximum perceptual equivalence to the original. Such image will be displayed properly by any software, either color or non-color managed.Many display profiles have no perceptual table included, so even if you choose Perceptual intent, they still effectively operate in Relative Colorimetric mode. If your goal is "pleasing" results, not side-by-side matches with commercial print job proofs, using a real perceptual intent will help.I've done this myself for a number of monitors which have poor blacks and thus are prone to clipping shadows in Relative Colorimetric mode. Note that to benefit from this, software has to use Perceptual intent, not Relatively Colorimetric. GIMP can be told to do this. I'm not sure which other software has a user-selectable intent, which have it hard-coded, and which use Perceptual as that hard-coded default!Anyhow, to create such a profile, try this:# Create a copy of the .ti3 file so we don't over-write the existing profile... cp lcd-t-b100-g2.4-f0-k0-qhh-lut-200812232358.ti3 lcd-t-b100-g2.4-f0-k0-qhh-lut-200812232358_gm.ti3# Now generate a LUT-based profile with a gamut-mapped Perceptual table: # We profile a "reference" profile with the -S parameter - usually sRGB, # though you could use AdobeRGB or some other working space profile # instead,colprof -S /path/to/whatever_working_space_profile_you_use.icc lcd-t-b100-g2.4-f0-k0-qhh-lut-200812232358_gmThis kind of profile takes longer to generate, so be patient - add the -v flag if you want to see the progress... The resulting file, lcd-t-b100-g2.4-f0-k0-qhh-lut-200812232358_gm.icc will include gamut mapping in its perceptual table.Hope this helps, -- Alastair M. Robinson
