Image ALT text is an important accessibility feature for ebooks—it adds a description of the image, for readers who are vision-impaired or who otherwise might be interacting with the text in a non-visual way. You can add ALT text for your images in Hederis by using processing instructions, as follows:
Find the Image holder paragraph for the image that you want to add ALT text for
Insert a new “HED Processing instruction” paragraph below it (if you’re working in the Hederis Edit Text pane, see “Add a Paragraph”; if you’re working in Word, see “Editing with Microsoft Word and Using Word Styles”).
In your processing instruction paragraph, type the text ATTRS=ALT:
Next, type the text that you want to be added as ALT text for this image.
Finally, press Save.