Images
Media content should have alternative ways to access the content for those with disabilities. This includes providing a transcript for audio and video content, providing text descriptions of any visuals within a video, and providing text descriptions for any images that are conveying extra information not included in the surrounding text content.
Images
Images used to supplement content need to be described in text for visually impaired users. The length and detail of the description depend on the image. There are three different ways to provide text descriptions for an image. These are alt-text, captions, and long descriptions.
Alt-text
We will start with the most common way to describe an image, alt-text. Alt-text stands for “alternative text”, and it should describe any information contained within the image in a clear way for visually impaired users.
Please visit this link to see examples of good alt-text. Good Alt-text Examples [Link Opens Website].
Captions
Captions are the last way an image can help be described using text. Captions can also help provide context of an image to sighted users. For non-sighted users, the caption should supplement the alt-text of the image, not just copy it. Keep in mind that a screen reader will read both the alt-text and the caption of an image, so redundancy can be annoying to users of assistive technology.
Long Descriptions
Long descriptions are another way to describe an image using text. Long descriptions are used for images which have a lot of information to convey, such as an infographic, or any other image that contains lots of textual information. To ensure no content is lost to visually impaired readers, the text within an image should be written out and described as best as possible.
Long descriptions are typically located either at the end of the chapter, or in a separate section at the end of the book. The long description should be linked to from the image caption, so that the reader can quickly access it. At the end of the long description, there should be a link to go back to where the user came from to help users who are navigating using a screen reader.
Captions vs Alt-text
It is important to note the difference of these two ways to describe an image. Alt-text is not displayed on the page, and is only accessible when reading the content of the page through a screen reader. Captions are displayed under the image, and provide extra context to the image.
To summarize:
- Alt-text should be very descriptive, noting the important details of the image to the user.
- Captions should be less descriptive, noting any extra context the reader may need for the image.
- Captions and Alt-text should never be the exact same. This will annoy readers using assistive technology.