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: "Mike Eddington" <email@hidden>
- Date: Tue, 30 Nov 2004 15:41:13 -0500
- Importance: Normal
Title: Message
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.
mike
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