The weird measured L*a*b* values where because of a wrong white point, thank you. Now I start the spotread utility with -ew parameter, measure the white point of the display and the measured values looks really good. I am under dE of 1.6 for most colours except darker greens.
The web server is a feature of dispcalGUI, which is for easy calibration on remote devices e.g. phones. Until now, I went through the hassle of streaming PC's screen via VNC. Thank you again for your help. Martin On 8.10.2013 13:05, Graeme Gill wrote: > Martin Florek wrote: >> I was able to create a profile with the web server, it works perfectly. >> But I was unable to create a profile without the VCGT tag (and thus have >> non-linear gamma). Should I use tone curve with gamma = 1.0 (relative or >> absolute)? In the mean time I applied the calibration from .cal file >> with applycal, but I would like to have a profile directly created >> without this step. > > No idea - I'm not sure what web server you are referring to. > It's easy enough using the tools directly - you get a profile > without a VCGT by default. > >> Another issue with my profile is that Argyll showed average dE of 0.41 >> and max dE of 1.6 for my profile, but when I displayed L*a*b* of 30, 0, >> 0, with the same display brightness, my meter (colormunki design) >> measured L*a*b of approx. 49, 0, -22 > > L*a*b* is a white relative measure, and you are (probably) comparing different > white point relative L*a*b* values, ie. display white point relative > (typically > about D65) vs. D50 relative L*a*b*, hence the blue of b* -22. >> Another option is that Argyll's spotread does not work correctly with my >> colormunki meter (or the meter itself is broken). The color looks like a >> neutral gray color, without a tint compared to my x-rite color checker. >> I tried to measure a perfectly gray (i.e. "a" and "b" to be as close to >> the zero as possible), I got to a Lab values of 49.39, -0.16, 0.43 and >> the color on the display was strongly yellowish/brownish. Any ideas? > > Same thing. D50 relative neutral will look yellow brown when displayed > with absolute colorimetry on a D65 display. > > Graeme Gill. > > > ------------------------------------------------------------------------------ > October Webinars: Code for Performance > Free Intel webinars can help you accelerate application performance. > Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from > the latest Intel processors and coprocessors. See abstracts and register > > http://pubads.g.doubleclick.net/gampad/clk?id=60134071&iu=/4140/ostg.clktrk > _______________________________________________ > Lcms-user mailing list > Lcms-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/lcms-user > ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60134071&iu=/4140/ostg.clktrk _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
