[argyllcms] Re: DTP20 (Pulse) patch size error

  • From: "Philip Reed" <philipreed@xxxxxxxxxxxxx>
  • To: <argyllcms@xxxxxxxxxxxxx>
  • Date: Tue, 16 Aug 2011 04:14:56 -0400

If I try to scan un-tethered, the TID can be read if I'm very careful, but
any attempt to read strip A results in an error.

I checked again and yes, the patch widths are 6.4mm at most.  Perhaps 6.3mm.
I'm using a digital caliper.  If there is a scaling error, I'm not sure how
that would be introduced?  I'm using the same software and printer driver to
print the patches from ColorPort or Monaco.  I always make sure that any
scaling is off.

Any option that allows for the scaling of patch width and height would be

Does anyone have any opinions about the quality of profiles created with the
DTP20 versus the Colormunki?

Thanks for your help - Phil

-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Graeme Gill
Sent: Monday, August 15, 2011 5:44 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: DTP20 (Pulse) patch size error

Philip Reed wrote:
> Argyll doesn't ask to read the TID strip.  This is what I get:

If you do an un-tethered set of readings (ie. using the TID),
does it work any better ?

> The row patches from Argyll are 6.4 by 10 mm while the patches from
> MonacoPROFILER are 6.7 by 12 mm.  The TID patches are 6mm by 10mm for
> and 6mm by 12 mm for Monaco.

I'd be really surprised if a width difference of 2 mm is going to make
any difference, given how much margin it has over the length.

Are the Argyll patches really 6.4 mm ? (ie. is the average over
the length of all the patches in the strip ?).
I wonder if there is a small scaling error in the printing,
and it is enough to take the patch below its minimum.

> Is the instrument sensing bleed from the rows above and below that aren't
> being masked using the Argyll chart?  About a mm of the row above and
> isn't covered. 

Unlikely, since the aperture must be less than 6 mm if it is to read
the patch cleanly.

Looking at the test chart spec., it is possible to change the DTP20
patch length to some other values, although I haven't currently allowed
for it. I'll see about adding this for the next release.

Graeme Gill.

Other related posts: