In the last article, we looked at the basic structure and evolution of the DFE. Since it is functionally the controller for each piece of your print production equipment from proofers all the way up to production inkjet presses, it plays a critical role. However, the importance of that role is not just in how it controls the device and manages and prepares the incoming data, it is also critical in how it works with other DFEs in a plant production workflow.
Each device is shipped with a DFE from the device manufacturer. In some cases, like the Canon Océ PrismaSync, HP SmartStream, Kodak NexPress and Kodak 700, or the Xerox FreeFlow Print Servers, it is a DFE the manufacturer developed from the ground up and is used exclusively in their device product portfolio. In other cases, like the EFI Fiery Digital Print Server or the CREO Color Server, it is a universal DFE, and is customized to support each disparate manufacturer’s device features and requirements.
As we discussed, at the heart of every DFE is an interpreter. All of the products listed above, except the HP SmartStream, are built on Adobe technology. The HP SmartStream is built on Global Graphics Harlequin technology, except for the HP Labels and Packaging Print Server which uses Esko FlexRip technology. The Harlequin RIP technology has been around since the late 1980’s. For many, it offered a competitive differentiation to the Adobe CPSI technology. Being a smaller company than Adobe, Global Graphics is able to react very quickly; in fact, usually faster than Adobe to changes in PostScript and PDF file format changes, even though Adobe created those file formats and the applications that created the files. According to the Global Graphics site, “The Harlequin RIP has processed PostScript files natively since 1988 and PDF files natively since 1997, including rendering of live PDF transparency since 2002.” The Harlequin RIP technology is not only capable of processing the same files as the Adobe technology, but in a recent test performed by RIT, it was found to be currently the fastest RIP technology on the market.
Adobe OEMs, depending on the specific RIP, either use Adobe CPSI (Configurable PostScript Software Interpreter) only, APPE (Adobe PDF Print Engine) only, or a combination of both. As a refresher, CPSI is the primary software RIP that Adobe has been licensing since the early 1980’s. In fact, one of the first implementations was Scitex VIP (Visionary Interpreter for PostScript). This software is licensed in a SDK (Software Development Kit) that is composed of a lot of pieces of functionality that are assembled, integrated and configured differently by each OEM. Over the years, the OEMs have become very creative and have developed many value-added features to each of their implementations. Now, when PDF files are processed in a CPSI RIP they are first converted to a PostScript file stream, which can introduce some issues and variability, depending on the structure of the PDF file. In addition to the variability in implementations which can lead to differences in output of the same input file, many of the features found in PDF files are not natively supported. Image transparency is a perfect example of one of those features. The chances are, if you have a CPSI based DFE, you have probably already run into some problems with image transparency. Although some of the OEMs have developed significant workarounds to try to address some of those issues with their CPSI implementations.
In 2006, Adobe introduced APPE to address those issues and more importantly to offer native support for processing PDF files. By using the same basic PDF library technology that is used in the Adobe Creative Suite to process the files, processing reliability increased dramatically. Since that initial introduction, continued APPE development has brought greater adoption, speed and increased feature support, including PDF/VT, which will be discussed later in the series.
While some of the Adobe OEMs currently use either one of the core technologies or the other, some use a combination of both core processing technologies, as in the Fiery and CREO solutions. In those cases, they use a weighted decision-making system to determine which path the file takes. While APPE is the newer and more ideal processing technology for processing PDF files, there are still cases beyond just PostScript files where CPSI is the preferred path in these systems. These cases include ‘value-added’ features and even some workarounds for a very few PDF transparency and file attribute issues.
Before there were digital presses, there were CTP devices, and before that imagesetters (filmsetters). CTP devices still exist and probably will for a long time, since they produce plates for non-digital presses including offset, flexo and gravure. While I was previously discussing DFEs for digital print devices, the DFEs that drive CTP devices are very similar and in some cases identical. In fact, these were the developmental models for the digital print DFEs that exist today, so you will see many of the same features and even similar user interfaces. However, in the case of a CTP device, it is usually is making plates for many, if not all, of the presses on the floor, depending on the size of the plant. As a result, the DFE started to take on a new role as the hub of the plant production workflow for those print technologies. The CTP DFE was developed to support all of the relevant basic required features like file format support, preflight, interpreter, color management, trapping, screening, and device controls. When the CTP systems and their digital print offspring started to support digital presses, additional feature support was added to include basic imposition, soft proofing, JDF/JMF, and more recently layer management and VDP (Variable Data Processing), and the list of features keeps growing.
Solutions like Agfa :Apogee Prepress, Fujifilm XMF, Harlequin (through OEMs), Heidelberg MetaDimension, Kodak Prinergy, and Rampage started to take the new role of CTP production hub more seriously. This expansion into capturing the management of the plant workflow began to present new efficiencies as well as new problems. And while it is nice to have a production management hub, what happens when you start to bring in disparate pieces of equipment from a variety of vendors? Is the feature redundancy of the multiple full featured DFEs a benefit or a does it create problems and workflow silos?
In the next article we will look at the features, benefits, and issues that are associated with the expanded role of this new class of Workflow DFEs, as well as the entrance of the even newer specifically designed production management software solutions.
Remember, if you have any topics you think are important and would like us to cover during the balance of this series, please let us know!
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