New subject: Isocoated vs EuroscaleCoated vs. EuropeIsocoatedFogra27

7 Nov 2005

      Hello 

Very interesting data - thank you. Yes I was using perceptual - with relcol
differencies are smaller and Isocoated/EuropeISocoatedFogra27 are much
closer to each other than Euroscale.

However I don't fully understand your second picture - to what do you
compare the Lab values to get Delta E94? 

BR Jouni

...
 -----Original Message-----
From: eci-en-admin(a)lists.transmedia.de 
[mailto:eci-en-admin@lists.transmedia.de] On Behalf Of Klaus Karcher
Sent: 4. marraskuuta 2005 16:00
To: eci-en(a)lists.transmedia.de
Subject: Re: [ECI-EN] Isocoated vs EuroscaleCoated vs. 
EuropeIsocoatedFogra27

Marttila Jouni wrote:
  Hello

 I was just looking at some natural pictures with skintones etc..

 E.g. the picture attached where woman is drinking. By calculating 
 pixel by pixel the avg Delta E between

 ISOcoated and Euroscale = 4.36
 ISOcoated and EuropeISocoatedFogra27 = 3.57  EuropeISocoatedFogra27 and 
  Euroscale = 1.12

 So EuropeISOcoated is closer to Euroscale and main  difference seems to 
  come from luminance level, which is higher with
ISOcoated  than the two 
  others. 
Are you talking about perceptual conversions from PCS to Device unsing 
Adobe Euroscale Coated v2, Adobe EuropeISocoatedFogra27, and 
eci ISOcoated?

As I mentioned in January in the German list, the B2A0-Tables of 
PrintOpen Profiles (as used by the eci) induce this luminance 
displacement.

see:
http://digitalproof.info/perceptual-rendering/DeltaL.pdf

* euCo2 means "Adobe Euroscale Coated v2"
* isoC means ECI ISO Coated (PrintOpen)
* IsoC-G3-350-CF is a ProfileMaker5 Profil

and relTK means "relative colorimetric with blackpoint compensation"

eci ISO Coated's perceptual rendering is significant lighter than that 
of most other profiles and IMHO this shold be corrected in 
further versions.

On the other Hand, both Adobe profiles (Euroscale Coated v2 and 
EuropeISOcoatedFogra27) are imho not suitable for proofing 
tasks (using 
its colorimetric Tables), because the error produced already by the 
profiles (not by the proofing system!) makes it realy 
difficult to meet 
the close tolerances for proofing, as you can see in

http://digitalproof.info/profcheck/profcheck5ir1b1.html

regards, Klaus

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RE: [ECI-EN] Isocoated vs EuroscaleCoated vs. EuropeIsocoatedFogr a27