[argyllcms] Re: dispcal: Warning - RegOpenKeyEx failed with 2

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 04 Jan 2008 02:10:04 +1100

lee scratchy wrote:
1)I've seen that ARGYLL supports the HCFR colorimeter, but it doesn't seem to 
take reference\
> files(.thc) in account.....so how can I find out the right R/G/B mix ?

I can't say I really understand what the HCFR folks are doing with their 
files. It doesn't make any sense to me that they can "calibrate" an instrument
without an independent reference of some sort. So what I've done with
my driver is to hard code a reference of the particular HCFR I have
into the software. The reference was created by calibrating against
an X-Rite DTP94 on two particular displays. The validity of this calibration
depends greatly on the uniformity of manufacture of the optical sensor,
and the similarity of the spectral characteristics of the displays to
what is actually being measured. Without some sort of manufacturers
factory calibration for each HCFR instrument, I don't see what
else can be done for it.

AFAIK this unit is worthless without .thc files, which basically enables to find
> the proper white temperature

You'll have to explain how this is supposed to work.

2)I'm expecting to receive a Eye One Display LT unit.
in the Gretag SDK and in the HCFR software, they ask you to put the unit in a 
bag in
> order to "calibrate" the unit for LCD, and on a white background for CRT.

These are just black level and frequency calibrations. As I understand it,
the Eye-One Display 2 and LT are not meant to need black calibration to the
same degree as the older Eye-One Display 1, and the factory black calibration
is meant to suffice.

I've been told that the Eye One were giving more precise measurements thanks to 
> unit calibration required prior to each session.

I'm not sure where you got this information. It doesn't agree with
the information I have seen about the Display 2 and LT.

Graeme Gill.

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