One of the challenges involved in creating accessible image alternatives for students with print disabilities is having a way to identify and utilize the data needed to create, read, or interpret the image alternative. The accessible representation might be in the form of a text description which can be voiced by DTB software, or a tactile graphic that can be embossed on paper or displayed on a refreshable tactile display. The ability to present these types of content requires a set of specifications, called ‘metadata,’ and a set of rules about how to use the metadata, called ‘standards.’
We see the benefits of standards almost everywhere in our world, for example: time zones, drinking water quality, automotive safety, electrical power delivery, etc. Having a country-wide standardized electrical system which defines the current type, voltage, and plug design, makes it a common task to plug in an appliance and have it work properly instead of causing a house fire. Standardization improves efficiency, enhances safety, and reduces the cost of products and services.
You might not be aware of them, but in order for your computer to display or voice a page from the Internet, which seems an intuitive task to us, there are underlying standards for the networks which transmit the data, the language which contains the formatting commands which govern the appearance of the page, and the browsers which interpret and display the content in its intended format. Without standards, pages on the Internet would not display consistently.
The same concept applies to creating accessible image alternatives. Right now there are many ways to create alternatives for graphical content in a digital book. Images can be described in the text of a book, or the descriptions can be coded so they can be voiced by reading devices or software. The image can be separately produced as a tactile graphic using a variety of techniques which place a raised image on paper or a tactile display. Three-dimensional models can be made for the student to touch; and haptic systems are under development which can give sensory feedback as a person “touches” a virtual object.
At present, all of these techniques require significant human effort, specialized equipment, or both; which raises the cost and amount of time required for creating the image alternatives. However, if a set of standards existed for incorporating accessible alternatives into digital books, then authoring and reading tools could be developed to take advantage of them, thereby improving the efficiency and reducing the cost of creating the alternatives. Ultimately, students with print disabilities would have more timely access to a greater variety of accessible image representations.
The future electronic “book” could include not only the text, but selectively accessible alternatives for each image based on the learning needs of the user. These might include: a summary description, a long description, a simplified language description, or tactile representations of different types. Instead of having to create these image alternatives independently using separate tools and methods, through the acceptance of standards image alternatives can be integrated into, or referenced from, electronic books and be readily available to the student.