Introduction to PDF/A

David van Driessche Chief Technology Officer, Four Pees Treasurer, GWG

The Problem

Better when electronic?

•  I made my university thesis in 1994 -  MS-Dos 3.31 & Windows for Workgroups 3.11 -  WordPerfect 5 & Word for Windows 6.0 -  Saved on a floppy-disk -  Backup on an Iomega ZIP disk

• That is only 19 years ago…

What is long enough?

• For businesses in Belgium -  Direct tax documents: 5 years -  Added-value tax: 7 years -  Medical records for employees: 15 years

• For engineers -  Lifetime of a building / construction

• For libraries -  Forever…

The Solution!

Why is this the solution?

•  Invented by Adobe in 1993 -  Originally as electronic product documentation

and Internet format -  But rapid adoption elsewhere from 1996

• A good format! -  Focuses on exact visual representation -  Printer and platform independent -  Compact and complete -  Random access

And standardized!

• Adopted by ISO -  ISO 32000

• So also vendor independent!

Oooops

• Missing fonts • Font problems • Complex features •  Incorrect file structure • Corrupt PDF files • …

• Room for interpretation!

The Solution!

ISO PDF/A

• A subset of the PDF format • Developed and maintained by ISO • Designed to remove ambiguities from the

PDF file format -  With the aim to create documents that are

archivable for 50 years (at least) • An ISO standard that will never expire!

Vanilla or Strawberry?

• Different archives require different things…

• Different flavors of the PDF/A standard cater to that: -  PDF/A-1b, the basic flavor

•  Guarantees visual reproduction -  PDF/A-1a, the accessible (or advanced) flavor

•  Incorporates all requirements of the basic flavor •  Also focuses on the meaning of the document content

PDF/A-1b

Parijs Visual reproduction

PDF/A-1a

Parijs Visual reproduction +

Meaning

PDF/A-1a, Structure

Parijs Document Title Paragraph Paragraph Paragraph

PDF/A-1a, Tagging

Parijs Description

“WWII: American soldiers watch as the Tricolor flies

from the Eiffel Tower again”

Usability / Complexity

• PDF/A-1b -  Relatively easy to make -  Easy to make automatically (without human

intervention) • PDF/A-1a

-  Contains much more usable content -> great for searchability of archives and additional intelligence about archived pieces

-  Very hard to create automatically unless source already contains a lot of information

Demo

• PDF/A-1b versus PDF/A-1a

Evolution

• PDF/A-1a and PDF/A-1b will always remain valid standards

• But new versions of the PDF/A standard have been developed as well.

PDF/A-2

• Allows more modern PDF features -  Transparency -  Layers (optional content) -  JPEG 2000 compression

• Adds support for embedded PDF/A files • Adds a new flavor: “u” for Unicode

-  Intermediate in between “a” and “b” -  Requires only fonts to be correctly unicode

mapped but no structure or tagging

PDF/A-3

• Adds support for embedding arbitrary files • Examples

-  An email archived with its attachments -  An Excel spreadsheet archived with the original

spreadsheet embedded

Thanks! Questions?