W3C home > Mailing lists > Public > public-html-a11y@w3.org > November 2012

Image description extension review

From: Léonie Watson <tink@tink.co.uk>
Date: Fri, 9 Nov 2012 20:41:55 -0000
To: <public-html-a11y@w3.org>
Message-ID: <007301cdbeba$a82cdf80$f8869e80$@tink.co.uk>


A few thoughts, mostly editorial.




“This specification defines a longdesc attribute to extended descriptions to
images in HTML5-based content.”


The abstract doesn’t make sense (at least when read with a screen reader).


“This specification defines a longdesc attribute to associate extended
descriptions with images in HTML5-based content.”





The code examples all have null alt attributes. Could they be more practical


Also wonder whether some best practice examples of longer descriptions would
be helpful? The extension may not be the right place for them, but a
separate note might do the trick.



Use cases and requirements…


“There are many ways to ensure that users do not need to see images in order
to successfully interact with content.”


The emphasis in this sentence feels a little awkward. It’s on ensuring that
people don’t need to see the content to understand it, rather than ensuring
they can understand the content in spite of not being able to see it.


“There are many ways to ensure users can successfully interact with images,
even though they may not be able to see them.”



Use cases…


The definition list markup is a bit scrambled. Tidy version below to save
you a few minutes editorial faff.



<dt>Describing a well known image</dt>

<dd>There are many well-known images which are widely reproduced - Mona
Lisa, Washington crossing some river, the Da Vinci picture of the guy in a
square and a circle, Gerníka, Cubbin's "Lost", Leunig's "ramming the
shears". While different people know the images by different titles, and
some images have no

widely known titles, visually recognising the image is often an important
part of framing a discussion. Where the image itself cannot be seen, a

can often be used to offer the same recognition.</dd>

        <dd>Requires: Discoverability.</dd>


<dt>Describing a complex diagram</dt>

        <dd>In many environments diagrams are used to explain a concept or
transmit information efficiently. Where a user has a reduced ability to see
the image (poor contrast vision and other conditions are as relevant here as
a complete lack of vision), a description can enable that user to understand
the informbeing presentehe information being presented.</dd>

        <dd>Requires: Structured Markup, Inline, Reuse, Simple Return.</dd>

<dt>Teaching Accessible Development</dt>

<dd>In many environments producing content that is accessible to users
regardless of disability is a legal and/or market requirement.</dd>

<dd>Requires: Maintenance, Backwards compatibility.</dd>


<dt>A self-describing artistic work</dt>

<dd>For many pages the visual design of the page is an important part of the
message it conveys to a fully-sighted user, but the author would like to

as much of that design as possible to a user with low or no vision

<dd>Requires: No visual encumbrance.</dd>


<dt>Referring to an existing description</dt>

<dd>Many well-known images are already described by other sources. The
copyright on those sources is not necessarily compatible with repeating the
description, but there is little value in making a new one, and ***.</dd>

<dd>Requires: Reuse.</dd>



The last description seems to be missing some words (marked with *** above).





Léonie Watson


E. tink@tink.co.uk

T. @LeonieWatson

S. Leonie.Watson

W. tink.co.uk

Received on Friday, 9 November 2012 20:42:33 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:05:32 UTC