2 | Introduction
Generating Accessible PDF Files from Authoring Applications
“Creating Accessible PDF Files Using Authoring Applications” on page 53 provides an example using
Microsoft Word of how to use Acrobat’s PDFMaker to make an accessible PDF files from a word processing
application.
Even if you generate an accessible PDF file from an authoring application, you should then follow the steps
in “Acrobat 9 Pro PDF Accessibility Repair Workflow” on page 5 in order to identify any items that may
have been missed in the initial conversion or to add PDF accessibility features that are not provided by the
authoring tool.
Characteristics of Accessible PDF files
The Adobe Portable Document Format (PDF) is the native file format of the Adobe® Acrobat® family of
products. The goal of these products is to enable users to exchange and view electronic documents easily and
reliably, independently of the environment in which they were created. PDF relies on the same imaging
model as the PostScript® page description language to describe text and graphics in a device-independent
and resolution-independent manner. To improve performance for interactive viewing, PDF defines a more
structured format than that used by most PostScript language programs. PDF also includes objects, such as
annotations and hypertext links, that are not part of the page itself but are useful for interactive viewing and
document interchange.
Accessible PDFs have the following characteristics:
Searchable text
A document that consists of scanned images of text is inherently inaccessible because the content of the
document is a graphic representing the letters on the page, not searchable text. Assistive software cannot
read or extract the words in a graphic representation, users cannot select or edit the text, and you cannot
manipulate the PDF for accessibility. You must convert the scanned images of text to searchable text using
optical character recognition (OCR) before you can use other accessibility features with the document (See
“Step 2: Determine if the PDF is a Scanned Document” on page 5).
Fonts that allow characters to be extracted to text
The fonts in an accessible PDF must contain enough information for Acrobat to correctly extract all of the
characters to text for purposes other than displaying text on the screen. Acrobat extracts characters to
Unicode text when you read a PDF with a screen reader or the Read Out Loud tool, or when you save as text
for a braille printer. This extraction fails if Acrobat cannot determine how to map the font to Unicode
characters.
Interactive form fields
Some PDFs contain forms that a person is to fill out using a computer. To be accessible, form fields must be
interactive—meaning that a user must be able to enter values into the form fields (See “Step 3: Add
Interactive Features: Form Fields and Buttons” on page 8). Interactive PDF forms also have a defined tab
order allowing users of assistive technology to use the tab key in order to progress from one form field or
interactive control in a logical manner.
Other Features: Buttons, hyperlinks, and navigational aids
Navigational aids in a PDF—such as links, bookmarks, headings, a table of contents, and a preset tab order
for form fields—assist all users in using the document without having to read through the entire document,
word by word. Bookmarks are especially useful and can be created from document headings. Many of these
aids can be accessed using the keyboard without relying on the mouse (See “Step 3: Add Interactive
Features: Form Fields and Buttons” on page 8). and (See “Step 4: Add Other Accessibility Features” on
page 16)..
Making PDF Accessible with Adobe Acrobat 9 Pro