QTR-Quadtone RIP

Michael,

when you say "smoothed" out the bumps, what exactly do you mean? I have been working on Canson BFK Rives and on the warm inks, it will curve to about 50% and the 55% will dip but return to normal at 60%, Ex., 50% Lab B = 3, 55% Lab = 2.5, 60% Lab B = 3. Even though the Lab L curve is smooth with no real flat spots, it seems the Lab B curve has influence over the linearization process as well.

Phil

--- In QuadtoneRIP@yahoogroups.com, "mjmptpd" <michael@...> wrote:
>
> Howard,
> 
> Thanks for the note... It occurred to me last night that the problem might be bumps in the curve, so I worked it over a bit and managed to get it to work.  It's a little odd that the software doesn't smooth out on it's own, but I guess that's what caused the problem. 
> 
> When I used the software on the PC, I would input the data into a spreadsheet to ensure a smooth curve (because the paper and inks are not going to have significant bumps; those are entirely the result of reading errors).
> 
> 
> ---Michael
> 
> --- In QuadtoneRIP@yahoogroups.com, Howard Shaw <glassman@> wrote:
> >
> > I would try using less data points, say 21. I seem to remember reading 
> > on this board in the past that, even though the readings don't actually 
> > reverse, if the intervals are not reasonably smooth then this error can 
> > occur. The chances of this happening are increased the more data points 
> > you have.
> > 
> > regards
> > Howard
> > 
> > On 02/11/2010 05:34, mjmptpd wrote:
> > > Hi folks,
> > >
> > > I've used QTR on Windows a good bit, but I am trying to get to understand it on a Mac now, and it's giving me some trouble...
> > >
> > > I'm trying to linearize a profile that I am creating, and I am getting the error below:
> > >
> > > "invalid linearize curve -- not constantly increasing"
> > >
> > > However, the data is constantly increasing.  It goes from 0,0 to 100,100 without flattening out or going down at any point.  I've tried density data and running it through the linearize program to no avail.  I never had this problem with the old Windows version, except when there actually was a problem.  Any suggestions?
> > >
> > > Here's the data:
> > >
> > > Creating curve Q4800-UCmk-RR-60PMatte-Warm-Lin
> > > LINEARIZE       = "72.67 71.32 69.33 68.03 66.12 63.64 61.23 59.47 57.75 55.53 54.44 53.36 51.78 49.73 48.24 46.78 44.88 43.49 41.69 39.95 38.68 37.02 35.82 34.25 33.1 31.99 30.54 29.83 28.78 27.43 26.77 25.8 24.84 24.22 23.01 22.12 20.97 20.12 19.57 18.23 17.71 16.69 15.7 15.22 14.51 14.05 13.14 11.83 11.61"
> > > LINEARIZE_CURVE = 0,0 2.21,2.08 5.47,4.17 7.6,6.25 10.73,8.33 14.79,10.42 18.74,12.5 21.62,14.58 24.43,16.67 28.07,18.75 29.86,20.83 31.62,22.92 34.21,25 37.57,27.08 40.01,29.17 42.4,31.25 45.51,33.33 47.79,35.42 50.74,37.5 53.59,39.58 55.67,41.67 58.39,43.75 60.35,45.83 62.92,47.92 64.81,50 66.62,52.08 69,54.17 70.16,56.25 71.88,58.33 74.09,60.42 75.17,62.5 76.76,64.58 78.33,66.67 79.35,68.75 81.33,70.83 82.79,72.92 84.67,75 86.06,77.08 86.96,79.17 89.16,81.25 90.01,83.33 91.68,85.42 93.3,87.5 94.09,89.58 95.25,91.67 96,93.75 97.49,95.83 99.64,97.92 100,100
> > > Invalid linearize curve -- not constantly increasing
> > >    0     0
> > >   10  2055 **
> > >   21  4448 ***
> > >   31  5953 *****
> > >   42  7370 ******
> > >   53  9127 *******
> > >   63 11024 ********
> > >   74 12963 **********
> > >   85 15997 ************
> > >   95 17600 *************
> > > 106 20044 ***************
> > > 116 21832 *****************
> > > 127 24189 ******************
> > > 138 26284 ********************
> > > 148 28468 **********************
> > > 159 31092 ************************
> > > 170 34157 **************************
> > > 180 37306 ****************************
> > > 191 40625 *******************************
> > > 201 44365 **********************************
> > > 212 48083 *************************************
> > > 223 52298 ****************************************
> > > 233 55830 *******************************************
> > > 244 60852 **********************************************
> > > 255 65535 **************************************************
> > >
> > >
> > >
> > >
> > 
> > 
> > -- 
> > --
> > Howard Shaw
> > glassman@
> > www.howardshaw.org
> >
>