ImagePrint - The Heart of the Matter
ImagePrint - The Heart of the Matter
- Subject: ImagePrint - The Heart of the Matter
- From: Nick Wheeler <email@hidden>
- Date: Tue, 28 Jan 2003 09:10:34 -0500
Ink Splotters:
I have started to do an extensive series of tests of ImagePrint's behavior
for myself to test all of my assumptions, especially in light of comments
made by others. I will send this particular note to ColorByte, the
Colorsync and 9600 lists as well.
Please read Neil Barstow's reply to my post from yesterday. It is a good
expansion of some of the points I made in that post.
The essential point is that ImagePrint works wonderfully if your setup
behaves just like the setup that ColorByte has profiled (ditto for the
Atkinson profiles and really any well done profile for that matter). If
there is a calibration mismatch between your system and the one ColorByte
has profiled the results are less than wonderful. Terrible actually.
I have repeated this ad nauseum - the end user needs some way of holding his
system in calibration day to day. For most of us now that means using
profiling packages of some kind to do the job, which is not what they were
designed to do. Profiling packages were designed to provide that last nth of
characterization to an already well calibrated system. So if your device is
horribly non linear then the profiling software is not sufficiently up to
the task.
The testing I am doing now is aimed at deconstructing ImagePrint to figure
out what all is going on inside the black box in an effort to figure out if
there is a way we can get it to adapt to our individual situations. I can't
at the moment rely on ColorByte to do the job. With luck that will change.
------
>
on 1/28/03 4:03 AM, Neil Barstow at email@hidden wrote:
>
>
> so did you just profile the rip/printer/CB <profile> as if it were a complete
>
> [linearised] device as I suggested? Then convert to that RGB colourspace
>
> before sending into..imagePrint..??
>
>
>
> I think that might work.
>
>
This an absolutely correct description of what might be my approach. But I
am not nearly there yet.
-----
Here are some things I have learned since yesterdays tests (all in RGB and
Lab):
Thing #1) As near as I can tell ImagePrint operates completely independantly
of the colorsync architecture in OS X. No Colorsync calls.
Thing #2) Set up properly the screen preview in ImagePrint does a good job
of predicting how the system will behave. I was surprised by this as I
didn't think it would, but I had really never bothered to try to set it up
properly. It actually does a better job of predicting ImagePrint's behavior
than anything I have tried to date in Photoshop when printing with
ImagePrint. I found ImagePrint's preview especially useful in predicting the
behavior of various RGB working spaces when those color spaces were applied
to rgbcmyk and grayscale ramps. Remember ramps are just theoretical
constructs and not actual pictures, containing colors we would never
actually encounter in photographs (different deal for vector art).
Thing #3) The ImagePrint supplied profiles are a part of the "recipe". I had
thought not, but was wrong. So if you "turn off" the paper profile you
disable linearization too. So in the system - output - profile dialog the
correct printer profile has to be there in order for the system to be
linear. More on this at a later date.
Thing #4) Nothing I have done so far would disprove the notion that
ImagePrint converts all incoming data to Lab. In fact converting a file from
Adobe RGB (say) to Lab and opening it in ImagePrint and printing it (screen
goes wacky but it still prints) yields an identical result (visual, not
measured yet) to just opening the Adobe RGB file in ImagePrint and printing.
This is an important tidbit to those using ImagePrint who like to do some of
their work in Lab.
Thing #4) Don't jump to conclusions about how to use this software!
On to cmyk testing of ImagePrint behavior.
Nick
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