imagemap

Illogical Technique

Authors are not going to think about image maps when they want to use a complex image. If they want to use an image they will simply use img.

It is illogical to require img to be encased in an imagemap in order to provide a long description.

Semantics

Semantic elements and attributes improve communication. For details please consult the semantics document.

The semantics of an imagemap href does not provide a clear, direct, explicit, and strong semantic for an image long description. An imagemap href is a generic link.

Adds Needless Complexity

Requiring image maps to supply long descriptions would introduce needless complexity.

This in turn would make it more prone to authoring error as complexity confuses and leads to errors. longdesc is a simple link - no coordinates to figure out.

Programmatic Determinability

Programmatic determinability aids accessibility.

For a long text alternative provided through a link in an image map to be exposed to assistive technology programmatically would require a special marking on one area, such as a longdesc boolean attribute.

Impossible for One Link to Have Two Destinations

Overloading the mechanism of image maps with that of providing long text alternatives clashes in the case that you need both, an image map and a long text alternative.

The fact is image map syntax only works on a limited subset of use cases. It is impossible for one link to take a user to two locations. It is not programmatically determinable when an image already has a link, which is mapped to go to another page or a larger image.

Expecting all images that need long descriptions to not have a different task unrelated to a long description is unrealistic. Attempting to force dual functionality into single functionality is unworkable.

No Examples in the Wild

No examples in the wild of accessible long text alternatives with an imagemap have been presented for any of the use cases. No evidence exists that authors have or will use for accessible long text alternatives.

Retrofitting Problem

Any proposed solution should be easy for authors who are already publishing content with longdesc to retrofit their existing pages. imagemap possesses a radically different authoring pattern than longdesc. Because of this, retrofitting with imagemap would be difficult, labor intensive, and error prone.

No Educational Material

No tutorials, books, or documentation exists that explain to authors how to make an accessible long text alternative with an imagemap href.

No Evidence of Improvement

No evidence has been presented that an imagemap produces more accessible content for long descriptions than longdesc or that more authors would use it correctly.