Well, one of my customers, it's going to print a test job with some images
like the Altona test suit ones, some special color patches, an ECI 2002
color chart, but his question is: Witch are the standard densities to print
with UVI inks on polypropylene and PVC medias?, is there any ISO applicable
to the packaging sector?.
Best regards.
Leon B. Garcia
PSP
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.
This is of course just one example...
Jouni
------
what do you mean with "visually closer to Euroscale"? what is your
visual reference for Euroscale?
>
> Any comments regarding these three profiles is appreciated
>
> Jouni Marttila
>
I also compared some FOGRA27 with its Characterization data using Graeme
Gills "profcheck" tool (http://argyllcms.com/) but posted the results
only to the german list -- sorry.
You can find the results here:
http://digitalproof.info/profcheck/profcheck5ir1b1.html
The diameter of the bubbles is proportional to the Delta E 94 and ist
enlarged by factor 5 against a/b.
regards, Klaus
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http://lists.transmedia.de/mailman/listinfo/eci-en
Hello,
I was wondering if someone has already experience with the ISO norms for screenprinting and flexo?
- Is it usable for 4-color work only?
- We have the experience that even in offset witch is a very stable
en well controlled process it is not easy to reach the right results. I
think it is even more difficult to control screen- and flexo printing. Are
these steps well described is the ISO norm?
- Which media are described in the ISO norm for screen- and flexo
printing? They use a wider range of media then offset (where it is already
hard to find ISO conform media)
- Is there already more practical information on how implementing
these ISO 12647-6.2 and 12647-5 norms (like the Bvdm handbook or the Altona
suite?)
- Is there already a useful version for Screenprinting? I' have seen that there is a draft version 12647-5, when will it be ready?
Regards,
Jan
Yes - that was my experience also that PrintOpen seems to be only software
where relative intent behaves differently
>-----Original Message-----
>From: eci-en-admin(a)lists.transmedia.de
>[mailto:eci-en-admin@lists.transmedia.de] On Behalf Of Bob Marchant
>Sent: 11. marraskuuta 2005 14:13
>To: eci-en(a)lists.transmedia.de
>Subject: Re: [ECI-EN] Isocoated vs EuroscaleCoated vs.
>EuropeIsocoatedFogr a27
>
>
>
>On 11 Nov 2005, at 11:46, Marttila Jouni wrote:
>
>> Has Adobe and Gretag taken this hue
>> shift into consideration when designing their profile software?
>
>We don't have the same problem using Gretag software to
>generate CMYK
>separation profies
>
>Regards,
>
>Bob Marchant
>
>_______________________________________________
>ECI-EN mailing list
>ECI-EN(a)lists.transmedia.de
>http://lists.transmedia.de/mailman/listinfo/eci>-en
>
Hello
In Real World Color Management (page 71), there is comments about LAB
limitations. It shows hue shift especially in blue region. So this might be
coming from imperfection of LAB-space. Has Adobe and Gretag taken this hue
shift into consideration when designing their profile software?
Jouni Marttila
>-----Original Message-----
>From: eci-en-admin(a)lists.transmedia.de
>[mailto:eci-en-admin@lists.transmedia.de] On Behalf Of Bob Marchant
>Sent: 11. marraskuuta 2005 12:12
>To: eci-en(a)lists.transmedia.de
>Subject: Re: [ECI-EN] Isocoated vs EuroscaleCoated vs.
>EuropeIsocoatedFogr a27
>
>
>
>On 11 Nov 2005, at 06:32, Marttila Jouni wrote:
>
>> So actually from colour numbers relative is reproducing the hue much
>> better
>> than perceptual. Same thing can be seen if you draw ab-space at
>> L-level of
>> 30 and put those Lab-values there and draw a line from 0,0
>to 68, -112.
>> ISOcoated's relative colour is almost on the line.
>>
>> However how we experience the colours is another story...
>>
>Precisely.
>
>Regards,
>
>Bob Marchant
>
>_______________________________________________
>ECI-EN mailing list
>ECI-EN(a)lists.transmedia.de
>http://lists.transmedia.de/mailman/listinfo/eci>-en
>
Hello
Interesting colour at the tip of the AdobeRGB gamut. I checked the Delta L*,
Delta C* and Delta h* from original Adobe RGB Lab-values to ISOcoated
Lab-values
- with perceptual: DL* 0.1, DC* 84.1, Dh* 24.3
- with relative: DL* 2.8, DC* 82.0, Dh* 1.3
So actually from colour numbers relative is reproducing the hue much better
than perceptual. Same thing can be seen if you draw ab-space at L-level of
30 and put those Lab-values there and draw a line from 0,0 to 68, -112.
ISOcoated's relative colour is almost on the line.
However how we experience the colours is another story...
BR Jouni Marttila
>-----Original Message-----
>From: eci-en-admin(a)lists.transmedia.de
>[mailto:eci-en-admin@lists.transmedia.de] On Behalf Of Bob Marchant
>Sent: 10. marraskuuta 2005 18:26
>To: eci-en(a)lists.transmedia.de
>Subject: Re: [ECI-EN] Isocoated vs EuroscaleCoated vs.
>EuropeIsocoatedFogra27
>
>
>
>On 10 Nov 2005, at 11:15, Andy Psarianos wrote:
>
>> I have tried to reproduce this blue/purple problem a few
>times now and
>> have been unable to reproduce
>
>Hi Andy.
>
>Make Adobe RGB file (or sRGB if you prefer) .Fill with LAB reference
>30,68,-112.
>
>Preview with ISO coated in relative and perceptual modes. See the
>difference in hue (hopefully!)
>
>Prior mails may have mentioned colours that are not real. We shoot
>flowers that fluoresce into ultra violet and infra red, products with
>spot colour , fluorescent backgrounds etc etc. We know that we don't
>stand a chance of matching these colours in CMYK , but a good profie
>will give a good first stab at it without shjfting the hue too much
>.Ir's mostlly at the cost of saturation.
>
>The ECI profiles seem to lose saturation with perceptual colorimetric
>rendering intent , and shift hue in saturated blues with relative
>colorimetric intent. Building profiles with the FOGRA data using
>Profiemaker 5 is giving us better results, and building profiles with
>the same software using our own data does likewise.
>
>BTW we proof to ISO standards and get the same results , so it's
>apparently not a screen thing.
>
>Hope this helps.
>
>Regards,
>
>Bob Marchant.
>
>_______________________________________________
>ECI-EN mailing list
>ECI-EN(a)lists.transmedia.de
>http://lists.transmedia.de/mailman/listinfo/eci>-en
>
Erstmal tausend Dank an die "Macher" des alternativen Medienkeils:
meiner Meinung nach ein riesiger Schrit in die richtige Richtung!
Ich freue mich auf die Diskussion darüber habe zwei Fragen:
Ein Zitat aus
http://www.dmt.uni-wuppertal.de/proof/index.php?tmpl=alternativ.php#wahrn
> Anforderung Wahrnehmungstreue
>
> Der MSD sieht die Bestimmung der Farbabstände nach der
> Farbabstandsformel ΔE76 vor. Diese Formel berechnet den rein
> geometrischen Abstand zweier Punkte im CIELAB-Farbraum.
> Bekannterweise ist dieser jedoch nicht in allen Bereichen visuell
> gleichabständig. [...]
>
> Aus diesem Grunde wurden Versuche unternommen, die Wahrnehmungstreue
> der Farbabstandsformel durch Einbringen empirischer Faktoren zu
> vergrößern. Die aktuelle Version der ΔE-Formel, die CIEDE2000 (ΔE00),
> liefert erwiesenermaßen Ergebnisse innerhalb menschlicher
> Farbempfindlichkeitsschwankungen (Berns, Roy S.: Billmeyer and
> Saltzman's Principles of Color Technology, Wiley-Interscience, 2000),
> und ist daher für die Beurteilung von Digitalproofs besonders gut
> geeignet. [...]
>
> Ferner macht es Sinn, für die unbunten Felder des Prüfkeils eine noch
> engere Toleranzgrenze festzulegen, weil Farbänderungen in Farben nahe
> der Unbuntachse für das menschliche Auge auffälliger sind. Diese
> Toleranzgrenzen könnten beispielsweise auf ΔE00 <= 2 für bunte Farben
> sowie ΔE00 <= 1 für unbunte Farben festgelegt werden.
Mal abgesehen davon, das sich wahrscheinlich so mancher
Softwarehersteller eine Farbabstandsformel wünscht, die etwas weniger
"tricky" zu implementieren ist ;-): Sind die getrennten Toleranzen für
Bunt- und Unbunttöne nicht "doppelt gemoppelt"? Wird die
Gleichabständigkeit nicht schon durch ∆E2000 hinreichend berücksichtigt?
Frage 2: Ein visuell bewertbarer Keil muss natürlich an die jeweilige
Ausgabebedingung angepasst sein. Da nicht alle Stützstellen des Keils
direkt aus den Charakterisierunsdaten abzuleiten sind, stellt sich die
Frage, wie die Sollwerte gewonnen werden können. Am einfachsten sicher
über ein Profil für die jeweilige Druckbedingung -- dann gehen aber auch
die Fehler dieses Profils (im Falle von isoCoated beispielsweise ein
∆E94 bis zu 0,8 im Cyan/Blau-Bereich) in den Keil mit ein. Wie lässt
sich das vermeiden?
Grüße, Klaus Karcher
Ok - now I get it - thanks again.
Interesting software this argyll but not too user friendy for those not
customed to use command promts
Jouni
>-----Original Message-----
>From: eci-en-admin(a)lists.transmedia.de
>[mailto:eci-en-admin@lists.transmedia.de] On Behalf Of Klaus Karcher
>Sent: 7. marraskuuta 2005 11:24
>To: eci-en(a)lists.transmedia.de
>Subject: Re: [ECI-EN] Isocoated vs EuroscaleCoated vs.
>EuropeIsocoatedFogra27
>
>
>Hi Marttila,
>
>you wrote:
>> 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?
>
>For the first picture I took a gray ramp in Lab (0/0/0 thru 100/0/0),
>converted it to CMYK unsing the profiles and rendering intents
>specified
>in the legend and then converted it back to Lab using the absolute
>colorimetric intent of the particular profile.
>
>The data for the second picture comes from Graeme Gills "profckeck"
>utility, documentation can be found at
>http://argyllcms.com/doc/profcheck.html
>
>As Test point data file I used FOGRA27
>(http://www.color.org/FOGRA27.html) converted to argylls ti3-Format.
>
>Klaus
>
>>
>> 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
>>>
>>>_______________________________________________
>>>ECI-EN mailing list
>>>ECI-EN(a)lists.transmedia.de
>>>http://lists.transmedia.de/mailman/listinfo/eci>-en
>>>
>>
>> _______________________________________________
>> ECI-EN mailing list
>> ECI-EN(a)lists.transmedia.de
>> http://lists.transmedia.de/mailman/listinfo/eci-en
>>
>>
>
>
>_______________________________________________
>ECI-EN mailing list
>ECI-EN(a)lists.transmedia.de
>http://lists.transmedia.de/mailman/listinfo/eci>-en
>
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
>
>_______________________________________________
>ECI-EN mailing list
>ECI-EN(a)lists.transmedia.de
>http://lists.transmedia.de/mailman/listinfo/eci>-en
>
