[argyllcms] Re: Dispread white drift compensation problem

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 19 Dec 2014 11:49:26 +1100

Vallo Kallaste wrote:

> I recently aquired i1D3 colorimeter and am testing or "getting to know" it.
> I noticed that colprof profile check results have very large difference
> depending on the usage of dispread white compensation, -Iw.
> Test data (.ti1 file) is same, the difference comes only from -Iw usage.
> Monitor is in native, uncalibrated state and warmed up. Linked are two tone
> response graphs from dispcalGUI, I did not use it for else.

> colprof -v -qh -al (dispread with -Iw):
> Profile check complete, peak err = 105.085290, avg err = 4.181563, RMS = 
> 7.683822
> colprof -v -qh -al (dispread without -Iw):
> Profile check complete, peak err = 4.465727, avg err = 0.536961, RMS = 
> 0.668549

        seems like some serious problems there. Without more detail (i.e.
-D 6 log of the dispread -Iw case), I can only guess, but my guess would
be that there is a timing problem - the patches have not stabilized
when the readings are being taken. One way of diagnosing if this
is the case would be to set the ARGYLL_MIN_DISPLAY_UPDATE_DELAY_MS
environment variable to a large value (i.e. 800 msec) and see
if that makes the problem go away.

See <http://www.argyllcms.com/doc/Environment.html>

Graeme Gill.

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