A basic guide (see post #1) to setting up ARGYLL CMS profiling on your computer

[Emulator]

Yes, it is indeed very intriguing. Now with this emperical knowledge one can create pretty good real world printer profiles with just 480 patches on just one sheet of A4 paper. I have made a similar profile with 960 patches and there was no improvement at all (2x480 on 2 sheets of A4 paper). Especially the B&W printing quality is very good indeed. I had a spyder4print before and even with the B&W optimisation chart it never produced good B&W.

Actually the neutrality is even better compared to a Colormunki with 2 optimizations (including a B&W neutralising image).

Now what I have done is using the "-N0.75" argument in the targen command to increase the amount of neutral points around the neutral axis.

I have update post #1 to include the 480 patch .txt file.

Did you find -N0.75 had any beneficial effects?

 

[pharmacist]

Actually: I do not know if without the -N0.75 argument is will become worse, so I suggest you to try this argument in targen. I just use this argument and the result is actually pretty good indeed .

 

[sampheap]

Amazing! Thanks a lot for walking us the starters in ICC with Agyll and ColorMunki Photo.
Hope to see more sharing.

 

[Emulator]

Amazing! Thanks a lot for walking us the starters in ICC with Agyll and ColorMunki Photo.
Hope to see more sharing.

Glad it helps. PRINTERKNOWLEDGE trys to make those difficult tasks easier.

 

[Emulator]

Actually: I do not know if without the -N0.75 argument is will become worse, so I suggest you to try this argument in targen. I just use this argument and the result is actually pretty good indeed .

I have tried Targen with and without -N0.75 on the CAP 480.bat. The differences are most easily seen on the simulated colorchecker display of Gamutvision which displays the small differences in delta Eab for the two profiles, probably not detectable with the naked eye! First image with -N0.75 and second image without -N0.75.

 

[mikling]

According to Argyll documentation.

"The -N nemphasis parameter allows changing the degree to which the patch distribution should emphasise the neutral axis. Since the neutral axis is regarded as the most visually critical are of the color space, it can help maximize the quality of the resulting profile to place more measurement patches in this region. This emphasis is only effective for perceptual patch distributions, and for the default OFPS distribution if the adaptation parameter is set to a high value. It is also most effective when a pre-conditioning profile is provided, since this is the only way that neutral can be determined. The default value of 0.5 provides an affect about twice the emphasis of the CIE94 Delta E formula."

 

[pharmacist]

There is a trade off when one wants to produce profiles for others: a preconditioning profile is rather inconveniënt in this case and equals the two step method of the x-rite software. So I think the 480 patch with the N0.75 argument is good compromise with pretty good results.

 

[Emulator]

The Argyll documentation is open to differing interpretations.
This emphasis is only effective for perceptual patch distributions, ..................... if the adaptation parameter is set to a high value.
This may be irrelevant when using other than perceptual.

 

[mikling]

I've bothered Graeme enough to question him on this, but maybe someone who has not bothered before him can do so and report on his comments and elucidate the documentation.

For the users of Colormunki devices, Argyll suggests using a lot less targets on one page there must be a reason. Graeme knows the hardware inside out According to the documentation... . "A table of useful total patch counts for different paper sizes is shown below." Take a look ( click on the underlined table). How do you overcome this suggestion by such a large degree? I thought you were using the printtarg meant for an i1Pro to use with the Colormunki device. However when you look at the number of patches recommended between these two devices, their required read windows and thus patch size appears vastly different.

My point is that perhaps the improved results you are obtaining might be due to getting back closer to the size of patches required for the CM device to capture a proper reading ( since you reduced the number on a page) and not necessarily the -N parameter.

 

[pharmacist]

Hi Michael,

You might be right. I also increased the patch length by elongating the rows before printing, so the relative reading time of each individual colour patch is longer (more samples taken by the Colormunki of each individual colour patch). I should redo my same setup with the same elongated patches, but without the N0.75 argument and see if there is any degradation or nothing at all.