[argyllcms] Re: Writing plot values from xicclu to text file
- From: Fritz Mahnke <fmahnke@xxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Wed, 24 Apr 2013 23:29:07 -0700
Hi Graeme, thanks for your help. When I run xicclu with -g, it tells
me the white and black points used for the plot:
./xicclu -v 2 -g -kz -fif -ir -l290 felt_ecru_avg.icc
Plotting from white 100.000000 -0.000000 0.000000 to black 25.450458
0.041596 -0.761814
I find that I can interpolate the L*, a*, b* values between the white
and black and get the correct values to plot:
L* a* b*
0 100 0 0
10 92.545 0.004 -0.076
20 85.09 0.008 -0.152
30 77.635 0.012 -0.228
40 70.18 0.016 -0.304
50 62.725 0.02 -0.38
60 55.27 0.024 -0.456
70 47.815 0.028 -0.532
80 40.36 0.032 -0.608
90 32.905 0.036 -0.684
100 25.45 0.04 -0.76
(step 7.455 -0.004 0.076)
Inputting these values interactively gives me the same CMYK output
values as the plot I see when I use the -g parameter:
./xicclu -v 2 -kz -fif -ir -l290 felt_ecru_avg.icc
100 0 0
100.000000 0.000000 0.000000 [Lab] -> Lut -> 0.000000 0.000000
0.000000 0.000000 [CMYK] Lim 0.000001 (clip)
55.27 0.024 -0.456
55.270000 0.024000 -0.456000 [Lab] -> Lut -> 0.700478 0.611736
0.621188 0.000000 [CMYK] Lim 1.933402
25.45 0.04 -0.76
25.450000 0.040000 -0.760000 [Lab] -> Lut -> 0.619037 0.518780
0.745803 1.000000 [CMYK] Lim 2.883619 (clip)
Now, my only question is how the black point for the plot is chosen by
xicclu. The point chosen by xicclu is different from that of the
profile I'm using. Starting from the beginning:
./colprof -v -qm -b -cmt -dpp felt_ecru_avg
...
Black point XYZ = 0.039661 0.041151 0.030580, Lab = 24.048349 -0.023773 2.361485
./xicclu -v 2 -g -kz -fif -ir -l290 felt_ecru_avg.icc
Plotting from white 100.000000 -0.000000 0.000000 to black 25.450458
0.041596 -0.761814
How can I find the correct black point used by xicclu so I can
determine the right input values to plot (other than using xicclu with
the -g flag, which opens the window I don't want).
Thanks!
On Tue, Apr 16, 2013 at 11:13 PM, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote:
>
> Fritz Mahnke wrote:
> > Hi, I am working on a front end to xicclu/colprof would like to be able to
> > plot the graphs from xicclu in my own application.
>
> > When calling xicclu this way, I don't want the new window xicclu creates. I
> > just want to dump the input/output CMYK values so I can draw the plot in my
> > own window. How can I do this?
>
> Hi,
> don't use the -g flag. Feed your own values in, and plot
> the result.
>
> Graeme Gill.
>
>
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