Roger,
no, in fact I might have to print a lot of color patches on transparencies
and measure the resulting values from the Kallitype prints that would result
from all these transparencies. Today I check a software program called R
that I used a lot a long time ago to see if I could at minimum load a tiff
image and yes there is a package for this purpose. So I can read and write a
tiff file into a multidimensional array then I can do whatever I want with
it and write it back to as a tiff file. It would be relatively easy to
convert a B&W 16 bit image saved in RGB mode where each pixel value would be
replaced by the color needed to reproduce this greyscale value and save the
result to a new file to make the negative.
So I could use that method as a proof of concept to see if the idea of using
a lookup table would work without having to write a special program, would
save a lot of work. Then I would look for a way to put that table into a
profile.
All this is not kosher sort of speak it's not a normal use of a profile,
that I know but I'm curious to see if it could work.
I'll postpone all of this till after the holydays or next year.
For the time being, thanks,
YG
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Roger Breton
Sent: Sunday, November 19, 2017 11:59 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: How to do this?
Yves,
Are you saying that, in your application, you would not need to "print"
anything out? To create the lut16Type structure?
/ Roger
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Yves Gauvreau
Sent: Sunday, November 19, 2017 11:11 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: How to do this?
Roger,
sorry for the time it took me to respond. After a bit of reflection, here is
what I'd like to do, instead of writing a program to convert a black and
white image into a colored image that I would then use as a negative to make
some Platinum/Palladium prints. This program would use the same model or
idea of a lookup table just as the lut16Type provide. This way I would not
need to use an external program to convert my images. Ideally, this lookup
table would be embedded into the profile used to print the colored negative,
if possible of course.
Any idea on how I should proceed to create this lookup table and put it into
a profile somehow and if possible I'd like to embed or link it with the
printer profile.
It's very likely I'll buy an XRite ColorMunki spectrophotometer to profile
my printer and whatever else I can do with it, my monitor, my scanner, my
cameras, etc.
/YG
PS Q1 => No idea yet, any suggestion?
Q2 => contact print using UV light with alternative process printing and for
me that will be Kallitype and Platinum/Palladium. I'll also try contact
printing silver based papers like Kodak and using an inkjet colored negative
but this time on plain paper and tungsten lighting.
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Roger Breton
Sent: Saturday, November 18, 2017 12:05 PM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: How to do this?
Question 1 : How are you "measuring" the print in step 1?
Question 2 : How are you making a B&W photographic print from the
transparency? Do you have an enlarger? You print on Kodak or ILFORD or other
photographic paper? In a darkroom? With developer chemistry?
To me, the only relationship I can see here is "Original patch values"
(DeviceRGB or DeviceGray) to a print.
Seems to me, this fits the description of an Output profile.
/ Roger
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Yves Gauvreau
Sent: Saturday, November 18, 2017 9:42 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] How to do this?
I'm trying to find a way to do something like the following:
1- I have a patch sets, I print this on somekind of transparent
material.
I measure the resulting print,
Now I have the relation: original patch color => transparency
printed values, right?
2- I use this transparency as a negative to make a B&W photographic
print.
Then I measure the results of this B&W print.
And now I have the relation: transparency printed values (colors) =>
B&W photographic print values (grayscale), right?
Now using the above data, is there a way to convert a B&W original image to
the colored negative I need to print this image on photographic paper using
an ICC profile? How do I create one?
I see this here in Argyll docs, CCTIFF -> Color convert a TIFF or JPEG file
using a sequence of ICC device, device link, abstract profiles and
calibration files.
Some of you will ask why bother to do this, well all the methods I've seen
to create a digital negative as most of them call it, use a scanner as
measuring tool and none of them use any form of a ICC profile for this, just
curves inside Photoshop or again curves at the RIP level. It works and it
may be just fine.
I'm just curious to see if using another method and of course a profile
would be an improvement in any way shape or form.
Thanks in advance,
YG
