I must be doing some silly or really wrong. Or my data is really bad.
Wanting to experiment with the -K parameters, I tried the following:
-kp 0.35 0.55 0.80 1.0 0.5
and got the following 2 pages PDF which illustrate the resulting CMYK curves
for gray balance:
https://1drv.ms/b/s!AkD78CVR1NBqkLVVuUPQdQ54CDpo0w
I realize the Argyll output profiles only do "GCR" type of gray balancing
where Black starts at zero.
Going to continue reading up the stle, stpo, enpo and enle parameters...
Thanks for your patience and help.
/ Roger
