[argyllcms] Re: Calibration and profiling of wide format solvent printer
- From: Nikolay Pokhilchenko <nikolay_po@xxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Mon, 17 Feb 2014 19:05:11 +0400
17 Feb 2014, 13:12 +01:00 mbielowicz wrote:
>Hi all,
>
>I've finally found some time to setup printer into uncalibrated state and
>managed to disable all color management options.
>Printed charts look very different now compared to those attached to my
>previous posts...
>
>My workflow was:
>1. targen -v -d4 -p2.73 -s200 -f0 Roland_XJ-740_calibration
>2. printtarg -v -ii1 -R13 -pA4 Roland_XJ-740_calibration
>3. chartread -H Roland_XJ-740_calibration
>4. printcal -v -p -D"Roland_XJ-740 calibration" -i Roland_XJ-740_calibration
>At this stage you've needed to limit individual channels. Such low delta E vs
>delta % are usable with precaultion. But I'd recommend some channel limiting
>before profiling. By my opinion the limits should be about this:
printcal -v -i -p -x0 80 -x1 65 -x2 80 -x3 65 Roland_XJ-740_calibration
I.e. Cyan=Yellow=80%, Magenta=Black=65%. It's obvious for me that your pirnting
resolution and drop sizing gives are somewhat excessive for this media. If it's
possible you may change lower resolution to decrease the density by about 20%
and increase the printing speed.
>5. targen -v -d4 -G -f1323 Roland_XJ-740
>6. printtarg -v -ii1 -R13 -pA4 -K Roland_XJ-740_calibration.cal Roland_XJ-74 I
>thing there should be ink overruns. At least the wery wet patches without
>channel and total ink limiting. It's OK for the start. But you may finish with
>less ink quantities.
>7. chartread -H Roland_XJ-740
>8. colprof -v -D"Roland_XJ-740" -qm -S sRGB.icm -P -cmt -dpp Roland_XJ-740 You
>skipped quite inportant stage - the black generation parameter optimization
>which are needed for better results. If the profile isn't intended for
>practical print the -S and -P parameters are useless and consumes a lot of
>computation time. You may check the gamut shape by "iccgamut -s". It's faster
>than computing of gamut mapping and corresponding B2A tables.
>9. applycal -v Roland_XJ-740_calibration.cal Roland_XJ-740.icm
>Roland_XJ-740_calibrated.icm Now you have a profile with calibration which may
>be the start poing for production profile. The calibration included will help
>the targen to limit the total inks. But with such steep calibration curves
>(because of channel limiting absence) the TIL computation may be not
>consistent. You need to try.
>1. I want to estimate TIL and individual ink limits from calibration and
>profile,
> so which profile should I use with iccgamut/xicclu: with calibration
>applied or without it? You need apply the TIL value at the targen stage. The
>targen uses the calibration curves (I hope uses) and deals with actual TIL. So
>for TIL tests you need the profile with calibration. It seems to be right
>because the TIL by the profile with calibration data is lower as it shoul
>actually be.
>3. When I view printcal's charts, I'm somehow worried about black calibration
>curve,
> black response isn't straight line after calibration correction applied, is
>it ok? It's OK. But you need to play the black generation parameters hard (-kp
>or even -Kp) to obtain the best black behaviour in sight of gradient
>smoothness, ink consumption and black in the lights.
>4. Nikolay, You suggested me to put calibration curves into a spreadsheet and
>convert them
> into RIP usable form, enter them into RIP, enter limits and then do
>profiling.
> I've took data from .cal file and reflected individual curves by y=x line.
> May You take a look if something like following spreadsheet will do?
> Gnueric spreadsheet (You need to enable "Time Series Analysis Functions"
>plugin in Gnumeric => Tools => Plug-ins)
>http://www.fileswap.com/dl/Wu84arqPKu/
I haven't Gnumetric on my computers yet.
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