It is important to add alternate text to significant images so that users of AT will receive the same information that other users do.
Ensure that alternate text is meaningful so that it clearly conveys the purpose of the image.
How to Apply Alternative Text to Images
Alternate text can be applied in the Alternate Text field of the Object Properties dialog. Object properties can be accessed by selecting Properties on the Context menu of the desired Figure tag.
Meaningful and concise alternate text should not be more than 255 characters. Note that in the example below the alternate text being applied to an image that says "Red Balloon" is more descriptive than "Balloon" as alternate text.
Alternate text can also be added or edited for an image using the TouchUp Reading Order (TURO) tool. To add or edit the alternate text of an image using the TURO:
- Activate the TouchUp Reading Order tool by navigating to View > Tools > Accessibility > Touch Up Reading Order
- In the main document, locate the image that needs alternate text or edits to the alternate text.
- Activate the Context menu of the image and select Edit Alternate Text from the menu.
- In the Alternate Text dialog, make the necessary changes or additions.
- When finished, locate and activate the OK button.
- Repeat steps 1 through 5 as many times as necessary.
- Note the changes or additions to the alternate text on the image in the main document. It may be necessary to view the Object Properties dialog of a tag in the Tags pane to see the full alternate text for an image.
To see whether an image has alternate text applied or not, select Properties, then on the Context menu of an image in the Tags tree and review the contents of the Alternate Text edit field. Alternate text also appears next to an image when the TURO tool is active, or it will say the image has no alternate text.
For complex images, charts and diagrams that need longer descriptions than alternate text can provide (255 characters or less), text should be placed in-line, in a footnote or in an appendix to appropriately describe the image. When a description is provided within a footnote or appendix, a link should be provided from the image or caption of the image to the description.
Decorative Images and Remnants
Decorative images and drawing remnants should be turned into artifacts to guarantee they do not interrupt the flow of important information. Sometimes process lines, arrows, borders and other shapes are not automatically converted as artifacts. These items can be changed into artifacts by locating the object in the tag tree and selecting Change Tag to Artifact, on that object’s Context menu.
When in doubt, add alternative text to ensure all users receive information.