QTR-Quadtone RIP

On Dec 16, 2007 11:11 AM, Ernst Dinkla <E.Dinkla@...> wrote:

> Eric Neilsen wrote:
> > Ernst (or anyone that recalls), Could you quickly go over those
> differences
> > or give us a time frame to look at for info?
>
> A message from June this year that sums it up best:
>
> As Roy indicated, BPC is not part of the ICC spec at all: it is an
> Adobe abomination, one of which (as is often the case with Adobe) is
> not completely specified for third parties to be able to reproduce.
> ...
>
> Mike
>
>


Yes, BPC is not part of the ICC spec but I'd hardly call it an "Adobe
abomination".
Not having pure-black map to pure-black during ICC conversion I think would
be a
much more serious abomination.  Adobe came up with a scheme to do this and
it is documented how they have done it.
  (see www.color.org, ICC WhitePapers, click on Black Point Compensation)

I've included this scheme into the QTR-Create-ICC profiles and found the
results
identical to the results that Photoshop would produce, so it's easy to
reproduce.

(I should mention that the generic QTR-Gray Matte/Photo Paper profiles were
done
as XYZ matrix profiles and do not have the BPC builtin -- they depend on the
CMS).

Roy


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