Re: Real world experience w/ GMG and Oris RIPs
Re: Real world experience w/ GMG and Oris RIPs
- Subject: Re: Real world experience w/ GMG and Oris RIPs
- From: Terry Wyse <email@hidden>
- Date: Tue, 30 Nov 2004 15:56:37 -0500
Excellent work Mike. Maybe that will put to rest the doubts of those
that think GMG's iterative non-ICC approach is of questionable merit.
Terry
On Nov 30, 2004, at 3:41 PM, Mike Eddington wrote:
Here's a test that I hope is a little more accurate in determining the
validity of the iterative process as it pertains to GMG...feel free to
pick it apart if warranted.
Equipment:
Kodak XP4 Approval (target device)
Epson 4000 (proofer)
ICColor spectrophotometer
-A 7000 patch CMYK chart was generated in GM Measuretool 5's Testchart
Generator (actual patch count is 6930 and inclusion of any voronoi
points is purely coincidental). ;-)
-This chart and the ECI 2002 chart were output off a Kodak Approval
-The Approval ECI was then measured as target data for GMG, CMYK
values for the proofing device calculated using the target data and a
gamut file from an ECI printed off the Epson, and the profile saved
(non-iterative profile).
-The GMG profile was then iterated with the ECI chart (proofed off the
Epson 4000) several times until the average delta E fell below 1 (ave
dE .84, max 7.24 as reported by GMG's profile editor) and the profile
saved (iterative profile).
-After profile creation, the 7000 patch chart was output off the
Epson4000 twice. once using the non-iterative profile and again using
the iterative profile.
-The ECI and 7000 patch charts for the Approval and both iterative and
non-iterative proofs were measured with MeasureTool and the resulting
data compared to each other.
ECI chart results
Non-iterative proof to Target Proof
ave dE: 5.85
max dE: 11.36
Iterative proof to Target proof
ave: dE: 1.19
max dE: 7.28
7000 Patch Chart results
Non-iterative proof to Target proof
ave. dE: 6.34
max dE: 13.24
Iterative proof to Target proof
ave: dE: 1.63
max dE: 6.88
I'd say this shows that GMG is handling colors outside the ECI test
chart fairly competently during iteration and that the delta E data
presented using the ECI chart is a fair assessment of the profile's
overall performance. In others words, the iterative process GMG
implements appears to have merit. I suppose this does give a slightly
better impression for the ECI results in terms of average delta E,
but we're talking less than 0.5 delta E difference between the 1485
patches of the ECI to the 6930 patches of the larger test chart.
_____________________________
WyseConsul
Color Management Consulting
email@hidden
704.843.0858
http://www.colormanagementgroup.com
http://www.wyseconsul.com (coming soon)
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