Improving accessibility in ebooks
I’ve been learning a lot lately about accessibility in ebooks, for readers who use screen-reading software. Two things I’ve learned:
A PDF should include what are called “accessibility tags,” which provide navigation information to screen-reading software. For example (as I understand it), accessibility tags can help blind readers understand which lines are headings, which are paragraphs, etc., and can help them navigate more easily through the book.
Some PDF-creation tools automatically add accessibility tags during the creation process; others don’t. For example, Microsoft provides instructions for how to include accessibility tags when you’re creating a PDF from MS Word.
To find out whether a given PDF has accessibility tags, you can use Acrobat Pro, which unfortunately costs money (though it does have a free trial version).
(There’s lots more to this topic, such as making sure that the accessibility tags provide a good reading order, but this is enough for a start.)
- An ePub should include various kinds of accessibility metadata, describing (among other things) what accessibility features the book has.
Some ePub-creation tools automatically add this metadata during the creation process; others don’t.
To find out whether a given ePub has accessibility metadata, you can use a free tool called Ace by DAISY, which tells you what accessibility issues the ePub has, and which files those issues appear in (an ePub is really a bundled-together collection of files, mostly HTML files). And it provides links to more information about how to fix each problem. If you have the tools and knowledge to edit ePub files manually, it’s pretty easy to add any missing accessibility metadata.