Add image descriptions for complex images

An image description refers to longer and more detailed text being available for complex images that contain substantial information. It is always recommended to keep alternative text brief and under 120 characters to benefit screen reader usability.  

That is why for complex images including graphs and charts, diagrams and illustrations, flow charts, and maps, a two-part text-based alternative is required. This includes both alternative text and an accessible text version:  

• Alternative text – short description: used to identify the image and, if necessary, indicate where the longer image description can be found; it should be concise and provide a basic understanding of the image’s purpose
• Image – long description: a more comprehensive textual representation of the essential information conveyed by the image or interactive; it should provide detailed information that allows a person who cannot see the image to understand its content and significance

By providing these two-part text alternatives in Canvas pages, PowerPoint slides Word documents, you ensure that individuals with visual impacts or those who rely on screen readers can access the same information as those who can see the complex images. This promotes inclusivity and accessibility in digital content.  

Types of complex images

Graphs and charts

This includes various types of graphs, such as bar charts, line graphs, pie charts, and scatter plots. The long description should provide a detailed explanation of the data, trends, and key insights presented in the graph. 

Flow charts and organisational charts

Flow charts illustrate processes, workflows, or decision trees, while organisational charts depict the structure of an organisation. The long description should explain the flow, decision points, or the hierarchy represented in these charts. 

Diagrams and illustrations

Complex diagrams and illustrations are often used to convey information that the page text relies on. Long descriptions for these images should clarify the content, relationships, and concepts within the illustration.

Maps

Maps can be used to display geographical information, weather systems, or other location-based data. Long descriptions for maps should provide details about the locations, features, and any pertinent information depicted on the map. 

Alternative text

Always ensure that the alternative text includes a sentence about what is in the image and then: ‘Refer to image description dropdown’ so the student can easily distinguish which images refer to the longer image descriptions.   

For example, this diagram requires an image description. In the Alt Text field, it says ‘Independent Samples T-Tests. Refer to the image description’.

Image description

The way to create an image description in Canvas is by using the HTML code for the ‘details widget’.  This allows readers to toggle the Image description on and off as in the following example.

• Copy the code below for a details widget/toggle

• Paste the HTML code into the space below your image in the Canvas
• First you need to access the HTML Editor (1) – this can only be accessed when you are in ‘Edit’ mode on a page

• Paste the code for the ‘details widget’ in the space after your image
• Select ‘Save’ to save your work

For image descriptions (when alt text needs to be longer than 120 characters) always ensure that the alternative text includes a sentence about what is in the image and then: ‘Refer to image description in slide notes’ so the student can easily distinguish which images refer to the longer image descriptions in the slide notes. 

For example, this diagram requires a image description. In the Alt Text field, it says ‘Independent Samples T-Tests. Refer to the image description in the slide’s notes’: 

Image description 

In the slide notes write a sentence like the alt text to distinguish the image and then follow on with the long alternative text.