Add Alt Text to Meaningful Images
Every image that conveys meaningful information needs to have alt text. Alternative text should provide a brief description of what is seen in the image. Imagine you are describing the image to someone over the telephone.
- To add alt text to an image in InDesign, first, select the pointer option in the left-hand menu.
Then select the image’s container or frame. For some strange reason, InDesign isn’t designed to allow you to add alt text to the image directly. You add it to the image’s container. - With the image’s container selected, in the main menu, select Object > Object Export Options.
You can also right-click on the container (not the image itself) and select Object Export Options that way. Object Export Options is the title that Adobe uses for alt text. It is important to remember that although it is not named “alt text,” Object Export Options serves the same purpose. - Once the Object Export Options dialog comes up, select the Alt Text tab, then select Custom and type in the alt text.
- InDesign has the ability to recognize metadata embedded in the image file itself and can pull the alt text from the metadata if it exists. If you know that the image has embedded metadata that can be used as alt text, select the appropriate XMP option from the drop-down list of alt text sources. You can choose the Title, Description, Headline, or Other XMP. If you don’t know what XMP is, or how to use it, don’t! Just use the Custom alt text option.
Designate Purely Decorative or Redundant Images as Artifacts
If the image conveys no meaning of interest to screen reader users, or if the image duplicates the content in the text, you should mark it as an “artifact,” which is the equivalent of marking an image as alt=”” in HTML. Images marked as artifacts will be completely ignored by screen readers as if they weren’t there at all, which is what you want in this case.
To designate an image as an artifact, select the Object Export Options, then go to the Tagged PDF tag.
To learn more about writing effective image descriptions or when an image can be considered decorative, utilize the Poet Training Tool by The DIAGRAM Center.
Anchor Images to the Appropriate Location in the Document
In addition to adding alt text, you need to make sure the alt text is read at the right location in the document. To do that, you need to anchor the image to the correct location. In the upper right area of the image container is a blue square.
- Click on this square and drag it to the location in the document where you want the alt text to be read, then release the mouse.
- The blue square will turn into an anchor icon, letting you know that the image has been anchored to the text.
- This technique will leave the image visually in its current location, floating outside of the text. If you want to place the image inline with the text, hold down the shift key, then drag the image to the location in the text.
