Digital BW, The Print

I don't disagree with the goal of opening up linearization to all.  But many
people don't want to go down that route.  But even if they don't there is a
lot to be gained from profiling whatever greyscale they've got.  For
example, black only printing has been very popular for many.  I would argue
that the principal reason for this is its simplicity.  But the greyscale
output of black only is anything but linear.  If one could profile it,
though, then those users could get the benefits of a CM workflow (or
luminance managed workflow) even if the baseline isn't able to be
linearised.  The CMM has to do more work but at least it can do some work.

The greyscale on my 4800 with Epson Adv B&W is really very linear.  I don't
see the need for QTR with it for photo paper (assuming I stay with the
standard inks).  For matte paper I would like to try increasing the ink
limits to see if I can get a better dMax.  So with the 4800 and Epson inks I
am not going to be using QTR for its linearization.  Nonetheless, I would
like to be able to profile the luminance axis of its output and use CM to do
the dynamic range compression.

Regarding the number of observations, it is interesting to note that Bruce
Fraser mentioned to me he was going to be doing "a whole lot more" than 51
for the Adv B&W soft proofs.

As for why Jon went for QTR I am not sure but I would suggest that he needs
a RIP to drive his ink set and QTR works well and is cheap for his potential
users.  They can then provide "ink curves" for their ink set with just a
small additional cost to the user (Roy's $50).  They can customise the
"linearization" to what they think is appropriate by adjusting the variables
that Roy has provided (or tweaking the .quad files).  That is, the cost of
adoption is low.  But as I noted earlier in this post, the final greyscale
will still have a particular profile (black point, white point and gamma)
and I would argue that even Jon would do well to go this extra step and
provide a greyscale ICC profile that depicts this compressed dynamic range.
Typically, in Curves or Levels in PS, we adjust the black point and white
point of our image file to be (near) perfect black or (near) perfect white.
These two points will never correspond to the print on paper points.  For
these reasons alone it would be nice to use CM to do the necessary
compression.  I do not see Jon's choice of gamma as reducing the desire for
this.  

So I do see the ICC profiling as being independent of greyscale
linearization.  What we really need is some input from a colour engineer
with blinkers on.  By "blinkers on" I mean we need to convince him/her, and
this is very difficult to do, that we don't care about hue - just luminance
and that we want CM to just manage luminance.  Now tell us how to set the
tags and tell us how the different intents can be/should be employed.
Unfortunately this is a very foreign world for them.  It is quite hard to
get clear answers to questions like "if I create a kTRC tag which has this
shape and select the primary intent to Perceptual, what actually goes on?"
or "why are my highlights getting clipped when I have the media white point
set correctly and the kTRC correctly portrays the stimulus/response
behaviour of the printer?  Shouldn't they be compressed but not clipped
because the intent calls for it as part of its definition?" - especially
when they are not actively involved in what you are trying to achieve.