Send us your comments check if pdf is accessible this page. Enables math to be spoken in assistive technology products.
For several years, the PDF creator, Adobe, has made it possible for XML markup to be used to give the information on PDF files, a hidden structure that makes them accessible to speech synthesizers. The accessibility criteria should be adopted in the source document before it is created with Acrobat Distiller as this reduces the size of the PDF and the time needed to create the markup. A speech synthesizer can only read text, but cannot read images containing text, even if the content is simple. These complex PDF files are not accessible using a speech synthesizer unless they have been edited first. PDF files were not originally designed to be read using computers, but to be printed.
Ten years ago, PDF files were not accessible for the visually impaired when they were using tools such as screen readers. About five years ago, with the growing use of PDF files, Adobe created a technique to allow PDF files to be made accessible and to improve their structure. Which files need complex PDF accessibility? You need to make sure that a PDF file acts like a classic HTML page in relation to the speech synthesizer, without its visual appearance changing. This is where XML markup comes in. You need to use this markup language, which is similar to HTML, to make a PDF file accessible.
The XML markup is hidden so that users and ordinary readers cannot see it in the PDF. To begin with, you must force the reading order of the PDF file so that a Jaws-type speech synthesizer reads it, in a similar manner to the way that one would naturally read, starting with the footer after selecting the corresponding page number. You must then assess the content of the PDF itself. Examine and find alternatives to the images, and tag the changes in language that are needed so that the speech synthesizer can read them correctly, as well as any acronyms or abbreviations that are found in the file.
Do not forget to use the right XML markup with Acrobat. If you are making a list of important points, use bullet points as they will be correctly converted when your document is turned into an accessible PDF. Do not make paragraphs by using several carriage returns. When you use links, a clearly explained title should be provided. If you have complex forms in your PDF file, you should respect certain rules to make sure that your file is accessible: the visually impaired should be used to use the fields, so they must have descriptions.
In an accessible PDF file, a visually impaired person will use the tab key to navigate, to make sure that it works in a logical order. You must use Acrobat Professional for this and add the appropriate tags after creating your PDF file. If you have tables in your PDF file, you must create tags for the headers, columns and lines in order to make them accessible. You should also avoid using tables to create text in columns or to create images.
In order to make the navigation of your PDF file easier, you can create bookmarks using Acrobat Professional. To make PDF files accessible, you should never need to fully rewrite the information hidden in the PDF. You simply need to add XML tags to the content. The only case where a part of the text will need to be rewritten for accessibility is when acronyms or abbreviations have been used.
This procedure allows you to limit the number of mistakes arising from the PDF encoding. It is not currently possible to automatically render a complex PDF file accessible as one must continually consider which contents of the file are to be made accessible and above all the best way of doing this so that it can be read as easily as possible by the visually impaired. These days, it is possible to design a PDF with different software, but to make it accessible, this software must allow you to structure the PDF document with XML markup. If a tree structure already exists, some PDF creators are able to transfer the structure.
This will allow speech synthesizers to access the contents. If you are using word-processing software for example, you will need to use heading levels to create your PDF file, but that is not sufficient to make the PDF accessible. To do it properly, you will also need to use Adobe Acrobat Professional to insert XML markup into any PDF which is not tagged. This is a more difficult process because you will need to know XML markup language and have a good understanding of it.