[argyllcms] xicclu -g predictability issue

  • From: Elena [service address] <1007140@xxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Tue, 18 Jan 2011 17:41:02 +0100

Graeme,
always playing with xicclu K curves, I am a bit disappointed that a
predicted plot doesn't completely reflect what colprof will actually generate.

I started with a -qh profile which I know having quite accurate A2B table (the
3000 patches test chart used was read and averaged twice).
I choose this K curve with xicclu (you know why, also I let -L100 -l300 since I
noticed there's not any advantage to limit inks too much with this specific 
shape)

 xicclu -v -g -fif -ir -kp 0 0 1 .2 .5 -L100 -l300 test5.icm
 the plot: http://www.elenadomain.it/pub/argyll/predicted.png

I then generated the profile:

 colprof -v -y -D"test 3000+ab qh r1 300-100 kp 0 0 1 .2 .5" -qh -r1 -l300 -L100
         -kp 0 0 1 .2 .5 -ssrgb.icm -Otest5.icm ofps3000+ab

and here's what I got:

 xicclu -v -g -fb -ir test5.icm
 the plot: http://www.elenadomain.it/pub/argyll/actual.png

 the profile: http://www.elenadomain.it/pub/argyll/test5.icm

Can you explain me why this mismatch ? It's already troublesome to search
for a smooth K cruve, but then what, if the prediction is wrong ?
Thanks.

/&

 

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