[argyllcms] Re: spotread filters
- From: "Jacques Warnon" <j.warnon@xxxxxxxxxxxxxx>
- To: <argyllcms@xxxxxxxxxxxxx>
- Date: Thu, 5 Jun 2008 17:18:01 -0400
Thanks Graeme, I guess that's a little out of my league for the time being.
I got really excited when I first read about Argyll's custom FWA
compensation when used with profile. But since I'm profiling a CMYKRB
printer, I realize now I can't profile with Argyll. So when I saw the
option to put in a custom filter at the measurement level, I just wanted to
find out what that was about. Seems like I will still be editing
measurement files in excel for the time being.
I have asked this question to Gretag/Xrite before with no real luck, but I
will post and see if anyone has an idea. Our printing media (sublimated
polyester) seems to wreak havoc on colorimeters, especially in the
highlights. It seems similar to the effect of optical brightening agents,
but much more pronounced. Profilemakers optical brightening option doesn't
fix it, and a borrowed UV cut i1 didn't help either. If I were to put it in
simple terms, I feel like I need to calibrate my i1 spectrometer to my
media. But how does one go about calibrating a calibration device? It
seems to work well on coated papers, but fabrics are a different story.
Does anyone have any ideas about how I can incorporate some sort of
corrective transforms like FWA into my workflow? Keeping in mind of course
that one piece of the puzzle needs to be a CMYKRB output profile made with
Profilemaker. Maybe something like an abstract profile I could apply
between my input and output profiles, possibly using icclink?
I hope this isn't too out of the scope of the list. Thanks again, all.
Jacques
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Graeme Gill
Sent: Thursday, June 05, 2008 12:20 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: spotread filters
Jacques Warnon wrote:
> Sorry if I sound like newbie, becasue I am. I just searched through the
> archives, but haven't found anything yet. I was curious about the -F tag
in
> spotread and/or chartread (-F extrafilterfile Apply extra filter
> compensation file). How does it work, what does it do, and how do I go
> about using it? Is it just a place to specify an .SP file? Spotread
works
> correctly with my eyeone so i know that is working.
It's intended to compensate for an extra filter in the optical path of
the instrument. I added it to calibrate a telescopic adapter that
I built for my Spectrolino. The lens in it is acrylic, so it filters
a fair bit at the blue end.
> This is the result I get using one of the SP examples from the ref folder,
> so I guess its not just an SP file:
>
> D:\Argyll\spotread>spotread -c1 -F d50_0.0.sp
>
> Setting filter compensation failed with error :'Unsupported function' (No
> device error)
Yes, I don't think I've bothered to add that facility to the i1pro driver.
In some ways it's more straightforward because the XYZ is always computed
from the spectral, but the High Res mode will complicate things.
Creating a suitable compensation filter is a rather manual process though.
Graeme Gill.
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