Guidance: Editing PDF Image Tags
Topics on this page
- Check for Tags
- Editing the PDF Image Tags
- Adding Alternative Text to an Image
- Making an Image a Background Element
The tag elements identify the objects in a PDF document and determine how a screen reader interprets a document.
This module supplements “Making Accessible PDFs” and assumes you are working with Adobe Acrobat Professional 8.
First, check for tags in the PDF document by viewing “Tags” in the navigation panel.
To display the “Tags” navigation panel:
Click on View >> Navigation Panels >> Tags
The Tags panel will be displayed. This example shows the “Tags” panel docked to the navigation panel on the left.
To dock the panel, click on the “Tags” tab and drag it to the navigation panel on the left; then release the mouse button.
If the PDF is tagged, the tag panel will display a small plus sign (+) followed by an Adobe icon and the word “Tags.”
If the document is not tagged, the tag panel will display an Adobe icon, followed by the words “No Tags available.” Please see our guide to make accessible documents (PDF - 1.97 MB) for more information on adding tags to PDF documents.
To expand the tag tree, click on the “+” key (Striking the “Shift” and “8” keys in combination is a short cut to expand all of the tags.) This reveals a chain of all tags in the document: normal, paragraphs, lists, images, tables, etc.
Match the Tag with the element on the page by turning on the Highlight Content option. Right click on a tag, then select “Highlight Content”; the element will be highlighted with a thin blue box when the tag is selected.
Among the most common changes made to image tags in PDFs are:
- Adding alternative text to an image tag, and
- Making an image a background element (see below).
Alternative text attributes are required for all images that add value to the document. The image’s text attribute will be read aloud by screen readers.
The example below contains an image Acrobat reads as <InlineShape> with no alternative text. This could be called a number of items; figure, image, graphic, shape, etc. Alternative text must be specified for these items.
To add alternative text:
Right click on the tag.
A TouchUp Properties dialog box will be displayed; enter descriptive text into the Alternate Text box. Adding a Title is optional; a Title will help the screen reader interpret the image. Click on “Close” to complete the change.
Images that do not add value to the document and are purely decoration should be designated as a background object. These objects will not be announced by screen readers.
To make an image a part of the background:
From main menu bar click on Advanced >> Accessibility >>TouchUp Reading Order.
The “TouchUp Reading Order” window will be displayed.
Select the object that is to be made “Background”
Click on “Background.”
Click on Close.
This concludes the supplement “Editing PDF Image Tags”.