Using DocBridge Products to Create files according to the PDF/A-1b Standard with Compart
The PDF/A-1b Standard
PDF/A is the ISO-standard for the long-term archiving of electronic documents, which also ensures that in the years to come a document will be reproducible in the same form as it was created. From this perspective it is the archiving standard of the future. This norm specifies two levels of conformance:
- PDF/A-1b (basic): At this level an exact visual reproducibility must be given. At a later date, reproduction of the document must look visually identical however the internal parts of the content can be specified without any logical sequence.
- PDF/A-1a (accessible), in which the text must be capable of additional representation in Unicode and the document content structured so that the content correlation can be automatically read, as is required for documents to be free from anything preventing them from being read by a program.
More detailed information can be found at the PDF/A Competence Center website www.pdfa.org.
Preconditions for the creation of PDF/A-1b Files
Compart products support the creation of files which meet the PDF/A-1b standard. Files created in this way can be passed directly to an archive, making them fully accessible in the future.
In a PDF/A document all the relevant information to be displayed must be in the document itself, all texts, image data, vector graphics, fonts and color spaces. This requirement alone may discount documents in one form or another from conversion to PDF/A. Depending on the format of the datastreams to be converted, you will naturally need the appropriate input filter as well as any referenced resources. More on this subject below.
If you have already acquired a license for the PDF output filter for DocBridge Mill and have available the current version of the product, you already have all you need within the scope of your Compart license to create PDF/A-1b.
Which profile settings are required?
In order to create PDF/A-1b with DocBridge Mill, two tags in the profile of the PDF output filter mffpdf.pro in the <output> section need to be changed: <version> and <outputintent>.
For the <version>-tag the following parameter should be used:
1. As output format the value="pdf/a" should be set.
2. level="b" determines that PDF/A-1b is required.
3. The parameter strict must be set to TRUE. This strict mode should ensure that following uninterrupted processing in any event all the criteria for PDF/A-1b have been met. If this parameter is set and PDF/A criteria have not been met, the process will either be aborted with an error message or an attempt will be made to resolve the conflict automatically.
So the tag will look as follows:
<version value="pdf/a" level="b" strict="TRUE"/>
Furthermore, in the profile file mffpdf.pro <outputintent> must be specified. It determines for which output condition the PDF/A file will be created, to ensure an appropriate color profile. An example would be:
<outputintent name="Adobe RGB (1998)" />
Adobe RGB (1998) is a example for output to a screen. For the selected <outputintent> an appropriate "ICC profile" must be found by DocBridge Mill. (What is meant by an ICC profile can be seen at the www.color.org website, under the section "What is an ICC profile?".)
The Output-Intent setting Adobe RGB (1998) requires the file AdobeRGB1998.icc, provided that in the mffpdf.pro file, the ending for ICC-files in the <resourcelist> is designated icc. Ensure that the paths to all resources similar to the "ICC profile" in the <resourcelist> are available.
As already mentioned additional resources such as fonts need to be embedded in the output file. One way of attaining this is to set <fonthandling> to CONVERTTOTYPE3 in the profile mffpdf.pro. Assuming that all the required files are available to the input filter, DocBridge Mill will itself create a Typ 3 font in the PDF file from the font resources on the input side.
To prevent an abort by the protection mechanism in the MFFPDF filter to protect PDF/A output, it should also be arranged that DocBridge Mill does not run a “Binary Copy” or do "Binary Stamping". This processing can take place when a PDF is to be processed on the input side.
In the DocBridge Mill cpmill module set the "Binarycopy" mode to "never". Make sure that this is done explicitly for each opened FileOutputDocument. This setting will also inhibit “Binary Stamping”.
The same effect can be obtained in DocBridge Mill module cpmcopy with the optional parameters -nobinarycopy and -nobinarystamp.
Take note of the content in the log file to see if your other settings interfere with your intention to create PDF/A files. More details, such as how the options should be used can be taken from the "DocBridge Mill Administration Guide".
Finally, we recommend that you use a validation tool to check if your configuration settings have resulted in the successful creation of PDF/A files.