Digital BW, The Print

Steve, thanks! That gets me most of the way. 




--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale
<stevekale@b...> wrote:
> Lab is normally a three channel space: L (luminance), a and b.  Roy has
> stripped off the a and b.
> 
> With QTR we linearize L values ie we linearize luminance.  Linearize
means
> you want a nice straight line, ie uniform changes, in L value from
dMin to
> dMax.  If you have uniform change then you "have good separation" of
shades
> or grey.  Since we are most concerned with luminance (shades of light
> intensity) in B&W and not hue we are focused on L in the Lab space.
 (Gray
> gamma is RGB but with R=G=B and so one channel.)  We do not need to
focus on
> a and b at the edit stage.  So nice to have a Lab space without the two
> empty channels taking up disk space and memory.  So same as using
Lab but
> smaller files.
> 
> 
> > From: Djon <westsidemaurice@y...>
> > Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> > Date: Fri, 28 Jan 2005 12:33:41 -0000
> > To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> > Subject: [Digital BW] Re: Gray Lab Working Space and Printing with
Perceptual
> > 
> > 
> > 
> > Roy, I'm having a ball with QTRgui ...BUT...
> > 
> > Please explain in simple terms (I'm simple) the meaning and advantage
> > of a "pure gray lab working space"
> > 
> > The beauty of QTRgui seems it's unique ability to let us step away
> > from jargon-ridden methodologies, eliminating the necessity for
> > profiles... 
> > 
> > 
> >> I have a new download of a pure gray lab working space and printing
> >> profiles that take advantage of the color management system.   So
there
> >> are icc profiles for printing with QTR that do "perceptual intent"
> > conversion
> >> of your grayscale images.