Accessibility of Rich Media – Part 2 PDF Accessibility

Follow-up to Accessibility of Rich Media – Part 1 Mostly Multimedia from Sara's Mindbloggeld

Since Acrobat 5 PDFs started to become accessible. Adobe introduced a series of “tags” that could be used to enhance PDF accessibility.

PDF files should be used to display documents that need to be printed exactly as the author intends. Not as an alternative to HTML. Note that PDF documents containing columnar data, such as financial data are likely to be inaccessible to screen readers so consider publishing in another format as well.

As with HTML, you need to know what kinds of issues people with disabilities might encounter when reading PDF files.

Accessible PDFs must:

• Be created as well structured documents (using hierarchical heading levels as you might in HTML).
• With a clear reading order (for the screen reader to follow)
• Images should have alt text
• Not contain hot spots that are too small or hard to click on
• Provide good colour contrast
• Use clear and simple language
• Not have information relayed in colour only

NOTE: An easy way to detect whether a PDF has been created with accessibility in mind, is to open the Tags tab on the left, if you can see some document structure revealed there, then PDF Tags have been created.

Three ways to generate tagged PDF:
within MS Office when creating the document
by running the “make accessible” plugin on existing PDF documents
by hand create the PDF tags within code view yourself (but this is time-consuming)

Within MS Word (this will vary depending on the version)

To create a hierarchical structure
Use the heading styles to set different heading levels.

To create Alt-Tags

Select the image, then click Format, Picture, Web in the Alternative text window that appears enter your Alt Text.

Set the Doc Type
Like with HTML document type definitions you need to specify the language as english.

NOTES:

Finally you can run an ‘accessibility quick check’ to verify the accessibility of the pdf document within adobe acrobat 6.

Link:

There is a large .pdf document from Adobe on PDF accessibility.

Sara Lever : 24 Jul 2007 12:24 |  Tags: Ajax Flash Multimedia Pdfs Video |  Comments (0) |  Trackbacks (1) |  Report a problem