Rich and Complex Content

Images, rich content and other complex features of an ebook help many people make more sense of explanations in text. However, by their very nature these features are inaccessible to those with a print impairment and some images contain even richer information than the text and, as a consequence, people who cannot see the image can lose out on extra information.

An accessible image provides a different approach to the visual content, helping both sighted and non-sighted readers to access all key points and to interpret what the image is supposed to demonstrate.

Text and audio description are the most widely used way to provide access to images and can greatly increase the accessibility of an image depending on the impairment of the reader. Writing image descriptions is a skill and there are a number of resources available to help publishers and authors prepare these – description can vary greatly based on the requirement of the given context.

Depending on the workflow employed, image descriptions and alt text can be added to a document at various different stages. We naturally advise all content providers to insert any accessibility features as early on as possible – build them in from the very start a bit like you would on a construction site. Your author is an obvious place to start as they are familiar with their own text in a way that no one else is. They should be able to provide the nuances and contextual information that some rich content requires. However, they may not be aware of the accessibility requirements behind successful image description or indeed the technical requirements of this additional content, in which case it may fall to editorial or production staff in-house or even 3rd party vendors with an expertise in this area. The important thing is to formally build this stage in your production process into your workflow so that it just becomes a natural part of your ebook development cycle.

Most importantly, you need to identify what the images within your content require in terms of accessibility. Not all images require description or alt text – they may be purely decorative and if this is the case then you should make sure they are labelled as such. Screen readers and other  forms of assistive technology need to be able to let their readers know what an image’s purpose is and if something is purely decorative then there is nothing more to be done.

If your image carries meaning or relevant information then it is vital that you describe this to your reader. Alternative text provides screen reader software users with access to all of the non-text information. Some complex images require longer description. You may be publishing a table full of complex data and in this case a short description in the alt text is a good place to start and then a longer more in-depth analysis / description can be achieved in the long desc box.


The Accessible Books Consortium

ABC hosts a free 20 minute online training session on Accessible Images – describing what these are exactly and how best to tackle various types of images.  Very useful for beginners and handy for in-house awareness training.


textBOX is a publishing service dedicated to providing quality image descriptions for all digital media channels. New methods have been developed  for content analysis (ECHO) and image description (focus/LOCUS + PICTURE). Publishers can expect Word + HTML descriptions to be supplied alongside detailed dataBOX spreadsheets for all content.

The DIAGRAM Center

The Diagram Center provides a host of resources designed to help content providers with image description. The POET tool “is an open-source web based image description training tool that helps people learn how to describe the various types of images found in digital books including complex images such as flow charts and Venn diagrams.”

Alongside this the DIAGRAM Center also provides a set of comprehensive guidelines, samples and training. Work on these projects is on-going as accessibility features and products advance.

W3C’s Tutorial on Images

This is an extremely useful resource for accessibility purposes.

Complex Image Guidance

Published in 2023, this guidance tackles how to describe extremely complex images in their many forms.