QTR-Quadtone RIP

John

I'm not sure why you are opening the Qimage output file in Photoshop -
perhaps it's just curiosity. In any event, I don't think QTR looks at any
embedded ICC profile, if present. 

Here's how I understand these matters.

If you "Assign" a profile to an image, it would not affect how QTR would
print that image, although it would likely change the way you see the image
on your monitor. That is because you are not changing the RGB values of each
pixel (or gray value is grayscale) but you may be changing the meaning of
these values. 

However, if you "Convert" an image to an ICC profile, then its appearance
would not change on your monitor, but it would likely change how the printed
image appears. That is because the RGB values for each pixel would likely be
changed but the newly associated ICC profile would preserve its appearance
on the monitor. However, since QTR does not look at ICC profiles, the
modified RGB values would change the way the image is printed.

Here's how I use this info in my workflow:

1.	when working up an image in PS, I convert it to Gray-LAB (for
grayscale) or RGB-LAB (for an RGB image) early in the process. I don't think
it matters at this point whether I use Assign or Convert as long as the
image has one of the LAB (from the QuadToneRIP\Icc folder) profiles
assigned. You can convert/assign to the LAB profile at any time. I do it
early in the process because doing so can have significant effect on the
image histogram, and I think it's better to do it before I adjust the tonal
range pf the image, which I do early in the manipulation process.

2.	If the curves I intend to use for printing have an associated ICC
profile, I use this profile with the PS soft proof feature to preview how my
image's tonal range will be mapped onto the tonal range available for the
paper/ink combination for those curves. Otherwise I could use the generic
profiles for matte paper (Gray-Matte or RGB-Matte) or photo paper
(Gray-Photo or RGB-Photo).

3. Currently, I print from PS by saving a flattened tiff file once I am
happy with the image. I'm not sure of the process with Qimage. I currently
have the demo to see how beneficial it might be.

Tom Moore

> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of John Wood
> Sent: Sunday, October 30, 2005 2:10 PM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Confusion regarding Profiles and QTR
> 
> Hi.
> 
> I'm really confused about a particular point (well, in fact I'm
> confused about a load of things relating to QTR, profiles, Dmax, L*,
> etc etc etc - but this is the first question on my list!!!).
> Grateful for any help!
> 
> I have been playing around with QTR on Windows and my Epson 2200 for
> a few weeks.  I use CS2 and ConvertToB&WPro V3 for image
> manipulation (usually limited to dodging & burning), Qimage (print
> to file) for final print interpolation and sharpening and
> the "canned" QTR EEH curves for final printing on EEH (usually 75%
> cool 25% warm works well for me).
> 
> The print output file produced by Qimage does not have an embedded
> profile (when I open the file from CS2 it asks me if I want to
> assign a profile).  What should I do at this point - should I assign
> a profile before printing or not?  And if I do, which profile should
> I assign - Adobe RGB, Dot Gain 20%, or one of the QTR profiles?  Or
> does this not matter one iota to QTR?
> 
> I've tried to find the answer in the manuals and this forum but I'm
> hopelessly uneducated in this whole subject and totally overwhelmed
> by the jargon!
> 
> Thanks for any advice!
> 
> John Wood