A and B are the color parts of LAB. A is magenta/green and B is yellow/blue.
If you scan in RGB you'll pick up the color of the patches but if you scan
in grayscale only the density (L) will be saved.
For linearization it makes no difference. If you are trying for specific tones
then is good to see the color you have.
Roy
On Thu, Apr 21, 2016 at 3:36 PM, paulmwhiting@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
Was happy to find out that this tool works on Photoshop Elements (I'm on version 9), but a few questions remain:
1) page 2: What does B on the greyscale stand for?
2) page 3, says I can scan in either color RGB or greyscale. Why would I scan in RGB? (more on this later)
3) page 5: What do you do when the boxes on the greyscale patches don't all line up? I was able to improve the lineup by slight changes in my selection tool starting point. But it's kind of a trial and error deal. Is there a better way?
4) page 6: Related to 2): the final display shows data in A and B. Is that because the scanner used in the documentation was scanned in RGB and picked up a little color somewhere? When I scan in greyscale, those columns all show 0.
Other than those minor issues, this is a great tool. Much appreciated - is that your work, Roy? Nice job!
Regards,
Paul W.