Tools make PDF files accessible
- By William Matthews
- Jun 25, 2001
Officially, the era of accessibility began this week. New Federal Acquisition Regulations are in effect, barring federal agencies from buying information technology that is inaccessible to people with disabilities.
The new law, Section 508 of the Rehabilitation Act, requires agencies to buy IT that is accessible to people with disabilities. The law effective June 21 applies to office equipment, such as computers, and to agency Web sites. Federal agencies continue to grapple with accessibility on the Internet, and in particular with Web sites that use PDF files.
There are tens of thousands of such files on government sites, according to Greg Pisocky of the government systems division of Adobe Systems Inc., the company that invented the PDF.
The format is a favorite of agencies because it enables them to preserve the appearance of the government documents they post on the Web. But some PDF documents pose accessibility problems because they are difficult to access with screen readers or refreshable Braille devices used by people who are blind or otherwise visually impaired.
Adobe has taken several steps to overcome the problem. To help Web designers create accessible pages for users with vision impairments, Adobe has created the Make Accessible plug-in, which works with the latest version of its document exchange software, Adobe Acrobat 5.0.
Using the plug-in, designers can analyze the logical structure of PDF documents and attach "reading order tags" to page elements so that screen readers will be able to read them using Adobe's Acrobat Reader 5.0.
The plug-in and the reader can be downloaded for free from Adobe's Web site (www.adobe.com).
Adobe has created another tool for tackling its toughest problem: turning image files into files that can be read by screen readers.
Many PDFs, particularly the older ones, were created by scanning paper documents. The resulting electronic images look like text documents, but are actually pictures of text documents and, thus, cannot be read by screen readers.
"There are a lot of these. That's where the big problem with PDF has been," Pisocky said.
To convert scanned PDFs into text PDFs, Adobe created an optical character reader called Adobe Acrobat Capture 3.0, which sells for about $700. How.ever, Adobe also offers a free, downloadable optical character reader called the Paper Capture plug-in that works with Acrobat 5.0.
The plug-in can read a scanned PDF page in about 30 seconds and convert it into a text file. It can then be turned into an accessible PDF or saved as a text document.
Pisocky said the optical character reader is about 95 percent accurate. Doug Wakefield, a technology and accessibility expert for the Access Board, said that means there will be two or three mistakes for each 60-character line.
Even though Adobe's software is designed to spot inaccuracies and give page designers a chance to correct them, Pisocky said, careful proofreading is advised.
Files created with Acrobat 5.0 enable readers to use a broad range of keyboard shortcuts in place of mouse navigation and offer visually impaired viewers the option of high-contrast displays.
Adobe offers another accessibility service as well, Access.adobe.com.
This is a free Web-based service that permits Web users to send troublesome PDF files to Adobe to be converted into HTML or plain text. They should then be accessible to screen readers and Braille displays.