[argyllcms] Re: RGB Printer profiling and ColorSavvy CM2C

Allistair,

> ColorSavvy have an SDK
> available on their website which make it very easy (using a DLL) to read
> XYZ values from a printed target.

Possibly read them in an Excel spreadsheet?

> My primary interest is in RGB printer profiles, and so far I've played
> with Profile Prism (using an Epson Perfection 640 scanner as a
> poor-man's colorimeter), Argyll (both with the above mentnioned scanner)
> and Colour Confidence Print Profiler (which came with my ColorMouse).

OK.

> Now we come to my questions:
> Is there any special reason for the apparently random placement of the
> colour patches on the page?  (It makes scanning the patches with the
> colormouse an "interesting" task, since with no software support, the
> XYZ values have to be added to the .ti3 file by hand...)

Does the CMC allows reading in strips? Like the EyeOnePro?
 
> Does Argyll have to generate the target itself,

Argyll has to generate the target, no question.

> or can the patches be
> "hand-picked" or augmented?  I ask because in my experiments last night
> I got a remarkably good result with a mere 60 patches - much smoother
> than either Prism or Print Profiler.

I know, even with 60 patches it can do wonder!

> What I'd like to do is use a sparse scattering of patches, and then
> augment this in the "difficult" areas, adding some extra patches down
> the grey axis and in typical skin tones.

Hmmh, I'm not sure argyll can do that. Graeme?

> Finally, with both Argyll and Print Profiler (and to a much lesser
> extent, Prism as well), images printed using the generated profile
> generally have very good hue and saturation, but need further gamma
> correction to get the luminance looking "right" - in terms of Gutenprint
> controls, Composite Gamma needs to be increased to 1.1 - 1.15 or so.
> Any idea what's causing this?

No idea, here. Perhaps there are options to force Lithgness mapping one way
or another on the Profile command line? I have not looked closely enough yet
so I could not say.

Roger Breton  |  Laval, Canada  |  graxx@xxxxxxxxxxxx
http://pages.infinit.net/graxx

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