Job Definition Format (JDF) is a technical standard being developed by the graphic arts industry to facilitate cross-vendor workflow implementations of the application domain. It is an XML format about job ticket, message description, and message interchange. JDF is presently managed by CIP4, the International Cooperation for the Integration of Processes in Prepress, Press and Postpress Organization. JDF was initiated by Adobe Systems, Agfa, Heidelberg and MAN Roland in 1999 but handed over to CIP3 at Drupa 2000. CIP3 then renamed itself to CIP4.
The initial focus was on sheetfed offset and digital print workflow, but has been expanded to web(roll)-fed systems, newspaper workflows and packaging and label workflows.
It is promulgated by the prepress industry association CIP4, and is generally regarded as the successor to CIP3's Print Production Format (PPF) and Adobe Systems’ Portable Job Ticket Format (PJTF).
The JDF standard is currently at revision 1.4a. The process of defining and promulgating JDF began circa 1999. The standard is in a fairly mature state; and a number of vendors have implemented or are in the process of implementing it. JDF PARC, a multivendor JDF interoperability demonstration, was a major event at the 2004 Drupa print industry show, and featured 21 vendors demonstrating, or attempting to demonstrate interoperability between a total of about forty pairs of products.
JDF is an extensible format. It defines both JDF files and JMF, a job messaging format based on XML over HTTP. In practice, JDF-enabled products can communicate with each other either by exchanging JDF files, typically via "hot folders," or the net or by exchanging JMF messages over the net.
Acrobat 7 includes a menu item to create a JDF file linked to a PDF file. This starts with the 'intent' for the job. More JDF detail is added later in various steps of the production workflow.
As is typical of workflow systems, the JDF message contains information that enables each "node" to determine what files it needs as input and where they are found, and what processes it should perform. It then modifies the JDF job ticket to describe what it has done, and examines the JDF ticket to determine where the message and accompanying files should be sent next.
The goal of CIP4 and the JDF format is to encompass the whole life cycle of a print and cross-media job, including device automation, management data collection and job-floor mechanical production process, including even such things as bindery, assembly of finished products on pallets.
Before JDF can be completely realized, more vendors need to accept the standard. Therefore few users have been able to completely utilize the benefits of the JDF system. In finishing and binding, and printing there is a tradition of automation and few large enough dominating companies that can steer the development of JDF system. But it is still necessary for the manufacturers of business systems to fully support JDF. The same progress has not been made here probably because many of these companies are small specialty companies who haven't the resource to manage such development and who don't specialize on graphic production.
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Before describing the implementation of proofing in JDF, it’s better to know a little about the terminology that will be used.
The original input files have to be processed to be printed on the final press (interpreting, rendering, screening, color management....) and the same to be printed on the proofer (different characteristics). The decision on which of the processing steps will be executed once (common both for printing on the proofer and on the press) and which not will depend on many parameters (characteristics of the proofer device, user requirements, workflow requirements…). The proofing has to take in account the consistency between the press and the proofer.
In JDF 1.1, proofing and soft proofing were defined as an atomic process on which the input were all the parameters required for a successful process. This has some drawbacks:
From JDF 1.2 proofing and soft proofing were deprecated in behalf of a combined process to specify the proofing workflow. The job ticket explicitly defines the processing and provides the flexibility to implement them in different workflows. In order to do that, the atomic processes were made capable of keeping all the information necessary to specify different configurations/options.
It is impossible to describe proofing by a unique combination of processes which in turn will depend on the capabilities of the RIPs (Raster image processor), the devices used for proofing and the proofing production workflow. It is still possible to define a generic combined process for the proofing. This will allow it to describe its step in a workflow. The generic combined proofing process combines the following JDF processes:
The ordering is not completely strict (same result may be achieved with different order combination of steps), but there are some precedence rules: the first color space conversion must be done before the second one, rendering must be done after interpreting, screening in turn must be done after rendering and the second color conversion, ImageSetting/DigitalPrinting must be done after screening.
Compared to proofing, since no printed proof is produced, no ImageSetting/DigitalProofing processes are required. Moreover the rendered data is sent directly to the Approval process that must implement a user interface to show those data on the display and allow him/her to approve/reject the proof and eventually annotate it using digital signature. All the ordering consideration are still valid.
In a production workflow with proofing, there must be both the conversion of the input asset color spaces to the press color space and the one of press color space to the proofer color space. So in JDF two different ColorSpaceConversion processes are required and depending on the exact workflow and on the capabilities of the devices, they can be included in the same combined process.
Input data to the proofing combined process usually required both interpreting (with the exception of JDF ByteMap) and rendering. In these cases they will be included in the combined process describing the proofing step.
Two possibilities:
For printing the proof ImageSetting/DigitalPrinting process has to be specified at the end of the proofing combined process in order to define how the proof is actually printed.
Must be executed before the final production printing can be started.
HP currently incorporates JDF into its proofing products. Even if it’s only one step in the total process JDF cuts time from the printing process making printers more efficient because proofing traditional generation and delivery of proofs can take days.
HP sends PDF files to a remote proofing. JDF file enables the inclusion of job information (color profiles, job ticket details…) that is sent to the client. In the future marking up the proof and digital signatures for approval will be implemented.