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IDEAlliance Response to ECI Presentation at the Color Management Conference

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  • IDEAlliance Response to ECI Presentation at the Color Management Conference

    A keynote presentation by Darrian Young of ECI at last weeks PIA/GATF Color Management Conference has elicited an interesting and at times heated discussion online and off regarding GRACoL, G7 and IDEAlliance and its relationship to ISO 12647-2 and the work that ECI/bvdm is doing. W would like to go on record that IDEAlliance continues to seek understanding between the two groups who each have their own process control methods but both aim for targets within ISO 12647. In addition, we offer the following public points to clarify our position:

    1. It should be noted that Don Hutcheson, as Chair of GRACoL, suggested that ECI speak at the conference as a gesture of goodwill between IDEAlliance and ECI. IDEAlliance hoped that differences in philosophy could be aired in a cordial debate.

    2. ISO 12647 is a set of process control aims for different printing conditions of which part two (along with the corresponding part of ISO 2846 on ink color) is targeted at offset processes. It was generated by Fred Dolezalek (Convenor), Larry Warter (Assistant Convenor), David McDowell (US TAG Chair), Kurt Schlapfer (EMPA/UGRA), Tony Johnson (British TAG Delegate) and others in 1996 based on SWOP and other reference sources.

    3. IDEAlliance, who now hosts SWOP and GRACoL, has always intended that their efforts be in compliance with ISO 12647. We believe this to be so in the case of G7 since all aim values from ISO 12647 have been incorporated into the G7 process, and since GRACoL’s “ISO-compliance” was confirmed in early 2005 by the then-chair of TC130, Fred Dolezalek on a phone call, which included ECI’s Florian Süssl.

    4. During early development of G7 and new GRACoL and SWOP characterization data sets, we openly shared our research and sought input from a worldwide community including official standards groups from Germany (such as Fogra and BVDM), Japan, China and other countries, as well as non-accredited groups such as the ECI and the PAB discussion list. Based on feedback from this wide variety of sources and numerous beta testers, we amended the G7 process several times. One modification was to comply with the TVI gain spread specified in ISO 12647-2. Another was to better mimic the average print density curves of a multitude of press data from across the world, and yet another embraced a paper-weighted gray balance formula that yields a pleasing effect on any paper color. At all times our primary goals were strict ISO compliance, representation of typical CtP printing, and good compatibility with legacy data sets such as TR001, Fogra 27 and Fogra 29.

    5. The only possible debate about IDEAlliance’s (or any other organization’s) “ISO compliance” centers on how to interpret the family of TVI curves included in the original ISO 12647 document as non-normative examples of analog plate printing. The question of whether the curves were made normative in the last revision is moot because in fact the dictum in the standard is simply to “see” the curves. There is no required method of use and no tolerances are specified. A more fundamental problem is that the normative midtone gains as written in ISO 12647 requires that printing on all grade one/two papers be targeted at a midtone gain of either 20% for countries with a negative plate heritage or 14% for countries with a positive plate heritage. Because this creates two incompatible interpretations of print “appearance”, IDEAlliance chose to adopt a midtone gain close to the positive heritage point, despite the former predominance of negative plates in the U.S. This was done because the bulk of US printers were working with lower CtP gains, and as a goodwill gesture towards world harmony. In return it was hoped that the positive-legacy world would make a similar concession towards a TVI curve that better represents current “natural” or “undistorted” CtP printing.

    6. Apparently the most controversial aspect of IDEAlliance’s recent work is that we questioned TVI as a primary metric for a visual appearance standard. While TVI is valuable for measuring the healthy operation of an offset press, alone it does not define the vital visual metrics of gray balance, image contrast or image “weight”, and it is based on densitometry while the rest of ISO 12647 is colorimetric. By contrast IDEAlliance’s new G7 process, which was presented to the initial London PAB meeting in 2005, and submitted as a new work item at the 2006 TC130 meeting, defines gray balance, image contrast and image weight in a precise and 100% colorimetric manner. Also the G7 process (unlike TVI or other “Near-Neutral” processes) allows widely different printing processes or substrates to share not only common gray balance, but also common tonal contrast and image weight, regardless of paper type, ink quantity, screening type or imaging technology. This “shared appearance” concept offers a significant new default compatibility benefit when exchanging files between different imaging systems.

    7. The G7 process offers so many benefits to the printing industry and standards groups in particular, that IDEAlliance and G7’s inventor, Don Hutcheson, decided to give detailed methods and techniques to the industry free, rather than taking the more profitable route of licensing the technology. It is worth remembering that IDEAlliance represents not only printers but brand owners, creatives agencies, the majority of the North American magazine publishers, suppliers (including paper and ink companies), graphic arts technology vendors (including proofing systems and press manufacturers), as well as infrastructure suppliers (including Microsoft, Sun Microsystems and IBM). We have established educational and certification programs for G7 at the request of our members and global partners across the creative, design, print, and publishing communities. The impact of G7 affects many more industry segments than just printing. It is part of an end-to-end process control philosophy that serves each of the IDEAlliance constituencies in a complete color managed workflow.

    8. Rather than being developed in secret, the G7 process was shared openly with ECI and other organizations, beginning with a 2004 meeting between Don Hutcheson (GRACoL chair), Olaf Drummer (ECI chair) and Jo Brunenberg (Ghent Working Group) in Denmark, which led to the establishment of the PAB (Printing Across Borders) discussion group. Another G7 presentation followed at the first PAB meeting in 2005. IDEAlliance has always shared the concept openly in hopes that it would be adopted by all parties and imaging processes, and ultimately incorporated into the ISO standards work. At all times G7 has been open to public review, testing, comment, criticism and improvement by any and all parties. After conducting extensive global testing and receiving positive feedback on our new GRACoL and SWOP data sets, we proceeded, according to standards protocol, to submit them to ANSI/CGATS for ratification. As of December 17, 2007 they are now official ANSI standards, known to the ISO community as TR006 (GRACoL), TR003 (SWOP Coated 3) and TR005 (SWOP Coated 5).

    9. To remain compatible with the existing ISO 12647-2 standard, IDEAlliance worked hard to make sure that the equivalent TVI curve shape (derived from the GRACoL NPDC curve) lies midway between the two optional curves for negative 20% gain and positive 14% gain, and that it represents typical commercial printing with natural (undistorted) CtP plates. Our TVI curves remain within the dot gain tolerances of ISO 12647. We have done our best to support both ISO 12647 and a unified future while avoiding the redundancy of legacy film-based TVI curves.

    10. ISO 12647 does not specifically recommend or demand any process control or calibration method for achieving the aim values in the standard. IDEAlliance enthusiastically supports ISO 10128 – Methods for calibrating a printing system with digital data (presently in draft). This new standard includes three options for achieving the aim values in ISO 12647: the “near-neutral” method as exemplified by G7, a density TVI method as exemplified by the FOGRA/ECI/bvdm process, and a device link method. All of these are viable, interchangeable and compatible with one another as long as good printing is practiced.

    11. IDEAlliance has a policy that the term standard is only used when: 1) ISO/CGATS has approved it or 2) a guideline or specification of IDEAlliance becomes utilized in a predominant market segment. Regarding ISO/CGATS, IDEAlliance has used the term standard in relation to SWOP and GRACoL only when the specification has been approved. We have utilized the term methodology or process when describing G7.

    12. IDEAlliance provides its guidelines, specifications and techniques openly and freely to the industry. We are, after all, a non-profit membership association. The new IDEAlliance ISO 12647-7 2007 Color Control Strip is an example of one such color management tool that we are providing to the industry free-of-charge.

    IDEAlliance is proud to have facilitated the exchange at the recent GATF Color Management Conference. We regret any misunderstandings that may have occurred in the past and, again, re-affirm our intention to support and improve international standards to achieve a unified world under ISO TC 130. Early in 2008, IDEAlliance will seek to engage executive and technical staff from other standards-related bodies worldwide in an ongoing constructive dialogue to lower the decibel level and move toward closer international understanding and unification. We feel progress has been made and that in actuality we are not far from the goal of defining universal international characterization data.

    David Steinhardt, President and CEO, IDEAlliance

    Dianne Kennedy, GRACoL and SWOP Program Director, IDEAlliance
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