Complex Images
Difficulty: Advanced
Category:
- Content
- Presentation
Important and relevant content from complex images must be provided in an accessible way. The alt attribute is generally reserved for a succinct alternative (less than around 100 characters is a general guideline). For images that require a longer description, this long description text may be provided directly on the main page in the context of the complex image (e.g., in a data table or descriptive caption immediately after the image). Alternatively, an image can be given a longdesc attribute. The longdesc value must contain the URL of a page that contains the long description (<img longdesc=”chartdescription.htm”>). Due to very limited support in web browsers, longdesc is not suitable as the only method of access to the longer description page. Longdesc should be used in conjunction with a standard link to the long description page.
