Acrobat and Accessibility
Although you can create accessible PDF files in several programs, Adobe Acrobat Professional is required to evaluate, repair, and enhance the accessibility of existing PDF files.
This page outlines accessibility features of Acrobat X and XI. If you are using an earlier version of Acrobat, read the article on Acrobat 7-9 and accessibility.
What's new in Acrobat XI?
There are quite a few new and improved accessibility features in Acrobat XI, including the following:
- The "Set Alternate Text" option makes it much easier to add and edit alternative text for images.
- Options for Heading 1-6 are available in the TouchUp Reading Order tool (previously Heading 1-3).
- The accessibility checker and wizard are greatly improved.
TouchUp Reading Order
The TouchUp Reading Order tool allows a user to quickly add and edit PDF tags and view the reading order of elements on the page. Although it can speed up the tagging process, it does not take the place of the other tools mentioned previously. Certain tags, such as lists, are only available in the Tags pane.
To use the TouchUp Reading Order tool, selectfrom the right-hand menu, then select . If the Accessibility menu is not visible (it is hidden in version XI by default), make sure it is checked in the option menu () in the upper-right corner of the Tools sidebar. When the TouchUp Reading Order tool is selected, the view on the screen changes. All of the content is enclosed in numbered boxes. Each of these boxes represents a tag and the number corresponds with the tag number in the pane. The window will also open.
If you have TouchUp Reading Order open and don't see any boxes, your PDF document is most likely untagged.
You will notice a group of buttons with the names of several common tags. You can use these buttons to assign tags to a selected block of text or an object.
There are two ways to select an area of text, image, table, or other element using TouchUp Reading Order.
- Drag a box around an element using the crosshairs that have replaced the default pointer. It is sometimes difficult to select exactly the right area, but it is a little easier if you try drawing a box that is slightly larger than the element. Once you have selected a new element, you can assign some of the most common tags to that element by clicking on one of the several buttons.
- You can also select everything within a box by clicking on the number in the top-left corner.
Now that you have selected the text, you can assign a tag by clicking on the corresponding button. Once you select a button, Acrobat will place the selected content in the appropriate tag. If you have thepane open, you can view these changes instantly.
While in TouchUp Reading Order, you can also assign alternate text to images byon the image and choosing .
|Button||Adobe Tag||Additional information|
||Only H1-H3 are available in Acrobat X.|
||If you select the image and adjacent text then the image will be tagged as a figure and the text will be tagged as its caption.|
||Acrobat attempts to assign rows, columns, and headings. Sometimes it does this correctly, but this should still be checked with the table inspector.|
||Can be used to merge cells if they are incorrectly split.|
|Background||none||This will hide an item completely from a screen reader. It can be used on images and text.|
The Order pane allows you to change the reading order of the content on the page so it matches the visual reading order. To open the Order pane, select oror select in the TouchUp Reading Order tool.
At first glance, it resembles thepane, but there are a few differences.
- The document is divided into pages.
- Each element is numbered, and the numbers start over on each page.
- There is no hierarchy of elements; everything is on the same level.
These differences help make thepane a much easier way to reorder tags. To change the reading order of an element, just click and drag the tag to the location that reflects the correct reading order. This new order will be reflected in the Tags pane and when the document is viewed in Reflow mode.
When an image is tagged as a figure, the alternative text will appear in a black box in the upper left hand corner of the image. If it has no alternative text, the caption will read "Figure - No alternate text exists."
To add or edit alternative text, appropriate alternative text in the dialog box.on the image and select . Enter the
The Table Inspector allows you to easily identify and assign scope to table headers.
With the TouchUp Reading Order tool open, select a table and then select. You can now select table cells that should be headers. on a selected cell or cells and choose . A dialog box will appear.
If the selected cell(s) needs to be tagged as a header (<TH>), select theoption and assign a scope of either or . After selecting , you will notice that the table header cells will be highlighted in red and the data cells will be highlighted in gray.
Artifacts are elements that are ignored by a screen reader, much like an image with empty alternative text in HTML. Important text should never be labeled as an artifact. The easiest way to change an element to or from an artifact is with the TouchUp Reading Order tool. Select the element and press thebutton to make it an artifact.
To search for artifacts, go to thepane and select . A window will appear with several search options. Artifact is the default search, so click . If there are any artifacts, the search will identify them and allow you to change them to other elements.
To change a tag to an artifact in the Tags pane,on the item and select .
View "Structure types" in Acrobat XI
By default, the TouchUp Reading Order tool displays the reading order of the objects in a page, but this can be changed in Acrobat XI so that the tags or "Structure types" are displayed instead of the "Page content order". To make this change, select theradio button within the TouchUp Reading Order window.
This will change the view so that the white boxes in the upper left corner of each element displays the tag (e.g., "P" or "H1") instead of the reading order.
Other Tools and Features
"Set Alternative Text" in Acrobat XI
Alterative text can be added to all images in the document at one time using a great new feature in Acrobat XI. In thesidebar, select . The first image in the document will be highlighted and a dialog box will appear with a space to enter the alternative text.
The dialog box also has a checkbox that allows you identify an image as a(which is similar to alt="" in HTML) as well as previous and next arrows to navigate through all the images in the document.
Convert Scanned Text
Before you can create a tagged PDF, you must first ensure that the PDF contains real text. If it does not, you must either recreate the PDF file (if you have the original file) or convert it to include true text. To convert the document, select in the right-hand column, then select . The quality of the text depends on the quality of the source document. The conversion is usually fairly good, but you should probably clean up the document by selecting in the submenu.
Acrobat Professional X includes two different Accessibility Checks. The first, the Quick Check, is not very helpful--it basically tells you whether the file has tags or not. It doesn't identify even the most basic errors, such as missing alternate text. The accessibility "Full Check" (available in both Acrobat X and XI) is a much better option. This can be a good tool to ensure that nothing was overlooked (e.g., document language). To run the full check, selectin the right-hand column, > . The Accessibility check in version XI is a bit more complete than version X and provides better documentation.
As with HTML, a screen reader will read a PDF document by the order of its tags, but the order of the tags in a PDF may not be the same as the visual reading order. This is especially likely if the PDF contains multiple columns or other blocks of text or complex nested lists. The Reflow Tool will allow you to see the visual order of the document's content as determined by the order of the tags.
Select Ctrl + 4. If the document does not appear in the correct order while in Reflow view, the order of the tags will need to be changed.or
Read Out Loud
Read Out Loud is a voice synthesizer that is available in Adobe Reader and Acrobat. It allows you to have the content of a PDF document read to you, approximating what a screen reader user might encounter.
The Action Wizard helps automate multi-step processes, like the creation of an accessible PDF.
"Make Accessible" Wizard in Acrobat XI
The "Make Accessible" action Wizard in Acrobat XI is a great tool that includes several improvements over version X. It is a helpful way to ensure that you don't miss any steps while making your document accessible. It is especially helpful in identifying those easy-to-overlook steps like providing a page title or document language. To run the wizard, select the. The wizard will then run you through several steps:
- Add Document Description
- Set Open Options
- Recognize Text using OCR
- Detect Form Fields
- Set Tab Order Property
- Set Reading Language
- Add Tags to Document
- Set Alternate Text
- Run Accessibility Full Check
Missing from this wizard is a step to check the quality of your tags using the TouchUp Reading Order tool. Otherwise, it is very thorough and helpful. For most documents, running this wizard would be a great first step.
"Create Accessible PDFs" Wizard in Acrobat X
To use the action wizard in Acrobat X, selectin the right-hand column, then select . The wizard will guide you through five steps:
- Add Document Description
- Remove Hidden Information
- Add Tags to Document
- Accessibility Check (Full)
This wizard misses a few key steps such as recognizing the text using OCR, but it can still be a helpful for common issues such as missing page title.