Digital BW, The Print

Carl-
Agreed.  See my response to Steve above.  This is a problem with the 
ABW and this paper only.

Walt


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield 
<scho@m...> wrote:
>
> Walt,
> 
> I don't think the utility of the program is reduced.  Rather, the  
> measurement data are faulty, for whatever reason, and should not 
be  
> used in an attempt to generate an icc profile.  I think you should  
> instead try to correct the printing problem (e.g. adjust ink 
limits,  
> ink overlap, partitioning, etc.) that is producing the aberrant  
> measurements.
> 
> Carl
> 
> On Oct 18, 2005, at 11:43 AM, wwodets wrote:
> 
> > Carl and Steve:
> >
> > This is exactly the problem I mentioned in an earlier post about
> > profiling the Arches Smooth paper.  The Lab values were linear up 
to
> > a 90% gray.  After that (for the 92, 94, 96, 98 and 100% gray) LAB
> > values read: 19.39, 19.06, 18.70, 18.95, 19.39.  Rather than
> > correcting this nonlinearity, Create ICC produced an unusable 
profile
> > with a full scale, retangular spike between LAB 0 and LAB 8 (e.g. 
LAB
> > 5 was "corrected" to LAB 98).  So this supports Carl's 
description of
> > function (and, I think, reduces the utility of the program).
> >
> > The abnormailty in this case was produced, I think, by the way the
> > ink sits on the Arches coating: way too wet.
> >
> > Walt
> >
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl 
Schofield
> > <scho@m...> wrote:
> >
> >>
> >> Steve,
> >>
> >> Yes, I tried it and it works well.  It assumes you have values 
from
> >>
> > 0
> >
> >> to 100 and just scales accordingly (after sorting).  There is a
> >> potential for error if your D values (or inversely L values) to
> >>
> > not
> >
> >> increase with increasing gray values, but that would be abnormal.
> >>
> >> Carl
> >>
> >> On Oct 18, 2005, at 9:34 AM, Steve Kale wrote:
> >>
> >>
> >>> Actually Carl are you sure about this?  It should also need the
> >>> Gray value
> >>> else it does not know for what input the output was generated.
> >>>
> >>>
> >>>
> >>>
> >>>> From: Carl Schofield <scho@m...>
> >>>> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> >>>> Date: Tue, 18 Oct 2005 08:45:08 -0400
> >>>> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> >>>> Subject: Re: [Digital BW] ICC v. Transfer Function in Epson
> >>>>
> > driver
> >
> >>>>
> >>>> Paul,
> >>>>
> >>>> You don't need all of the data columns.  Just a single column 
of
> >>>> either visual density (labeled either D or V) or Lab L (L 
label)
> >>>> data.  The icc-create droplet will simply assume zero values 
for
> >>>>
> > Lab
> >
> >>>> a and Lab b if no actual data are present.  The density or L
> >>>>
> > values
> >
> >>>> can also be in any order and will be automatically sorted (high
> >>>>
> > to
> >
> >>>> low for L and low to high for D).  This with the 2.3.1 version
> >>>>
> > on a
> >
> >>>> Mac but I assume it is the same for the PC version.
> >>>>
> >>>> Carl
> >>>>
> >>>>
> >>>
>