The patches that appear "scalloped" are not. That is your eye/brain masking being made more apparent to you/us. (It's cool and tells us something about our visual system.)Pull the test strip into PS and measure the density with the eyedropper set to 1 pixel to convince yourself.PaulOn Sun, Apr 12, 2015 at 9:22 AM, paulmwhiting@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:Hello,
Here's a Dropbox link to the 21-step greyfile supplied with QTR:
https://www.dropbox.com/s/7gszzza0mcpod99/21step.tif?dl=0
I wan to measure the density of each step. I note there are three areas to this scale. The top area is a continuous scale, from dark to light. The second, or middle, area shows the steps but with a sort of "scallop" to each patch. The bottom area shows the steps separated by thin white lines, and the steps are more uniform than than the second area's steps.
It seems to be me I should be measuring density from the third, bottom, area to get a more representative reading. Is that correct? If so, just wondering why that middle area has "scalloped" steps. You may have to enlarge the view to better see what I mean.
TIA,
Paul
Message
Re: [QuadtoneRIP] question re: greyscale
2015-04-12 by Roy Harrington
Yes. Its just an optical illusion. But I also notice that the file you have here shows
some evidence of JPG compression -- little halos around sharp edges.
On the Mac distribution its a .psd file and does not exhibit this artifact. I don't
have the PC distribution immediately available for checking.
Roy
On Sun, Apr 12, 2015 at 9:32 AM, Paul Roark roark.paul@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote: