Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Ernst Dinkla <E.Dinkla@c...> 
wrote:
> Roy Harrington wrote:
> > 
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "ldina" <lbdina@c...> 
wrote:
> > 
> >>Roy, I was curious if you found the LAB Grayscale profile effective 
> >>and if you updated your original profile?
> >>
> >>I'm probably missing something, but it seems this would have to be a 
> >>generic profile by its nature.  If used for viewing the tonal range 
> >>on a monitor, how would it be able to differentiate between a high 
> >>gamut glossy paper (like Kirkland Glossy which can hit an L* of about 
> >>6) to lower gamut matte paper that can only display an L* or about 
> >>20?  
> >>
> >>Seems to me they would both display the same, but the output would be 
> >>very different.
> >>
> >>If you have found it effective, I'd love to know how you use it and 
> >>how you handle different paper types.  I'd also like to get your 
> >>latest profile if your results are positive.
> >>
> >>Thanks, Lou
> > 
> > 
> > Hi Lou,
> > 
> > I have been experimenting with this.  I find the Lab gray space better than
> > the gamma space.  At least I find the separations are better matched to the
> > print and to the eye.  But you are right about how different papers are
> > enough different that you can't switch back and forth without editing.
> > 
> > My current take is that the gray Lab space is best for editing, but that there
> > should be a way to do a mapping with perceptual intent rendering at
> > print time.   I think it's possible to have just a few profiles -- i.e. a
> > generic matte paper and a generic photo paper -- rather than making
> > a gazillion profiles for every combination.
> > 
> > Roy
> 
> Roy,
> 
> Is what you propose not already done in most RIPs (but in
> colour mode) ?  The linearisation of the channels separate of
> the profiling, the last to the Lab space/axis. In that way you
> could use the LittleCMS or Argyll engine for profiling. The
> fastest way now would be to use either Photoshop or Qimage and
> a B&W adapted ICC profile. Qimage makes RGB print to file
> output, as long as the greyscale isn't corrupted but only the
> steps shifted along the curve it would be right. Doesn't
> provide the right preview on color (tones) but the rest in an
> acceptable way. The linearisation takes care of the paper +
> printer + ink differences. The Lab curve goes on top of that
> and you could probably limit them to the two choices you
> mention, one covering up to 1.7 Dmax, the other to something
> like 2.1.
> 
> Ernst

Hi Ernst,

Yes, that's basically the idea.  The grayscale makes things somewhat
simpler though --  I can do the icc profiles myself.
On the Mac its just like printing with a color icc profile.  
I'm not as sure what the best Windows workflow would be.

With Qimage can you apply the profile as you save the "Print to
File"?   I think with Photoshop you'd have to Convert to Profile
and save the tiff file.

The other approach would be to do the perceptual rendering in
QTR using a simple curve.

Roy