Re: Media Testing for maclife.de
Re: Media Testing for maclife.de
- Subject: Re: Media Testing for maclife.de
- From: Chris Cox <email@hidden>
- Date: Fri, 12 Sep 2008 17:10:23 -0700
- Thread-topic: Media Testing for maclife.de
On 9/10/08 11:02 PM, "Uli Zappe" <email@hidden> wrote:
> Am 11.09.2008 um 02:55 schrieb Chris Cox:
>>> Let me point out that Capture One PRO (which I used for my ICC
>>> profiles) performs the white balance adjustment *before* the ICC
>>> profile assignment.
>>
>> Ah, so there was another process involved.
>> And you are not using the profiles for calibration at all, but only
>> for artistic intent and post-process color correction.
>
> Profiles are never used for calibration, but for profiling.
Then you don't understand how all of the software works.
(some attempt to use ICC profiles for part of their calibration)
> Calibration is the process you'll have to perform before profiling, be
> it a monitor, printer, scanner or - a camera. For the camera, this
> process is or at least includes setting the white balance.
This part might be a language issue - but it is important, and something
that you are apparently misunderstanding.
Characterization for a digital camera can generally be encapsulated into an
profile (relating sensor values to CIE colorimetry). The format of that
data does not matter.
But white balance is not directly part of the characterization because it is
very illumination dependent (not static from image to image). How to
achieve white balance under multiple lighting conditions should be part of
the characterization. But that part cannot be encoded into a standard ICC
profile. This problem has led some software makers to add other calculations
outside of the ICC profiles they use to hold characterization data.
Calibration would bring the data from the device into a standard - and the
characterization data can be used to do that (directly to CIE colorimetry is
the easiest, and derivable from the characterization plus white balance).
What you are attempting to test is the artistic part - after the calibration
has been achieved, after the white balance has been performed. Even if you
are trying to achieve colorimetric results, you are attempting to apply a
rendering via ICC profiles AFTER the calibration rendering has been done.
But you have to be very careful in the tests to know when the profile data
is applied, and something about how the calibration rendering is applied.
You cannot reasonably compare profiles for artistic rendering to profiles
used for calibration/characterization.
But that is what you tried to do.
>>> It's clear from this processing sequence that the ICC profile has
>>> no way to compensate for peculiarities of the spectral
>>> response of the camera sensor, since after the white balance
>>> adjustment, these have "moved".
>>
>> Which means you are not profiling the camera at all, but rather
>> profiling the RAW conversion software and making corrections/
>> adjustments to the processed RAW output instead of the camera RAW
>> data.
>
> So is *this* what in fact we're arguing about all the time?!?
One of your mistakes is that you didn't understand exactly what you were
testing (see above). But then you made bad claims based on that
misunderstanding, and attempted to compare things that were not directly
comparable.
>>> I don't know what this could possibly be, but wait for my upcoming
>>> report where I will try to describe my procedure in exact detail
>>
>> I would withhold that report until you correct your testing
>> procedure or account for all the processing stages.
>
> How can I account for all the stages if I don't publish the report?
First, learn what is going on as much as you can, then ask questions, then
get reviews from people who know the topic well, ask more questions of those
people, make corrections, get them to review again - when they approve, then
publish.
(more or less like a thesis)
> Look, you know nothing about me, about my profession, about my
> academic background. How can you say what you are saying here? Do you
> really believe the Adobe perspective on the world is the intellectual
> gold standard that cannot possibly be surpassed?
This has nothing to do with Adobe.
This has to do with your mistakes, and your bad conclusions/claims (some of
which involve Adobe software, some of which do not).
You failed to learn enough about the subject before writing the review, you
published your review and made claims that are not backed up by your
testing, you have continued to argue that your claims are valid after being
shown that they are not.
What would happen if you submitted a thesis to a university that contained
obvious mistakes and unsupported conclusions? Your advisor or the reviewers
would tell you that you had mistakes and that your conclusions were
unsupported and to please go work on it some more. Very much like I'm doing
here.
> I really wonder what you're up to. Are you even aware that your words
> from above effectively aim at destroying me as a public person?
I am simply trying to explain your mistakes to you and ask you to make
corrections.
> Is this the seriousness you talked about? Do you want to prevent me from
> providing the English translation?
If I were you, I would have removed the original review and put an apology
in it's place long ago. The translation should wait until you fix the
problems in the original review. Certainly you should withhold reviews of
the DNG profile technology and results until you understand what they are
doing and what they are for.
>>> Why is it unreasonable to assume that Adobe delivers default
>>> settings as good as possible for them?
>>
>> Because you don't know what the design goal was for those profiles.
>
> True, but the logically only alternative to the intent to deliver
> optimal profiles is to intentionally deliver suboptimal profiles. I
> don't say such a behavior is impossible, but users would certainly
> want to stay away from the products of such a company.
Again, you have problems with your logic.
Other possibly hypotheses: they default to a pleasing rendering, they
default to a popular rendering, they default to matching some other
standard, they default to a rendering pleasing to some unknown individual,
etc.
Until you ask someone to tell you the design goal used, you can't make any
assumptions about it. You might even be right, but you haven't obtained
any evidence to prove it -- so any claims about the design goal of the
profiles, or any claims that depend on knowing those goals are unsupported.
>> It would also help you greatly if, in the future, you asked
>> questions instead of making accusations.
>
> ??? What accusation?
Please re-read what you have written.
It might be just a translation issue, but many of your claims are more
forceful than expected in a review.
Chris
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