On Feb 21, 2008, at 3:00 PM, Florian Höch wrote:
What I'd rather see is go back to the color
test from previous
postings. A color space defined with NTCS primaries and varying
TRC's defined by gammas 2.3 through 2.6. So just like ECI-RGB,
except varying the TRC, and converting to the ISO Coated (ECI)
profile, with all the same parameters as the previous tests.
Ah! Ok, then I misunderstood you. I thought that such a test would
still
have the problems of relevance.
Well actually it would! :-) But the point is that if we get even more
CMYK values with one of those gamma values, then it's a demonstration
that the test is a problem.
I remain convinced we need a test that differentiates between the
loss of levels due to change of TRC, and the gain of encoded CMYK
values due to change of TRC.
We need to know if we even care about these 5 million or 6 million
colors as well.
/python_directory/python image_countcolors.py
path/to/imagefile.tif
This appears to be working. No error message after 1 minute and
python process is soaking up 60% of CPU.
Oh, and just to reiterate: I stated in my previous
post that I
actually
see your points (really!), thus, I was trying to make no assertions to
begin with (I see now that you thought I was trying to prove my
initial
assertions by posting the results. I should have only posted the image
and what I would do with it, then ask if such a test would be feasible
and if it would actually yield any meaningful results). I really just
wanted some input (which I got now, so, again, thanks).
Ah OK. No worries.
I would like to believe that whoever has pushed this L* idea onto the
ECI, and those who have voted on it, and in particular whoever on the
ISO committee looked at it, before making it an ISO standard, would
have very clear and reproducible evaluation that would demonstrate
why it's better, when it's better, when it's not better, etc. I
haven't seen anything like that yet.
Chris Murphy