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associating a group of related images to a common caption

From: Gregory J. Rosmaita <oedipus@hicom.net>
Date: Mon, 14 Jun 2010 17:03:27 +0100
To: public-html-a11y@w3.org, wai-xtech@w3.org
Message-Id: <20100614155911.M68081@hicom.net>
aloha!

currently, the HTML5 draft contains the following example:

QUOTE 

<figure>
<img src="castle1423.jpeg" title="Etching. Anonymous, ca. 1423."
alt="The castle has one tower, and a tall wall around it.">

<img src="castle1858.jpeg" title="Oil-based paint on canvas. Maria Towle,
1858."
alt="The castle now has two towers and two walls.">

<img src="castle1999.jpeg" title="Film photograph. Peter Jankle, 1999."
alt="The castle lies in ruins, the original tower all that remains in one
piece.">

<figcaption>The castle through the ages: 1423, 1858, and 1999,
respectively</figcaption>
</figure>

UNQUOTE

when what is needed is:

<figure>
<figcaption imgref="castle1423 castle1858 castle1999">
The castle through the ages: 1423, 1858, and 1999.
</figcaption>

<img src="castle1423.jpeg" title="Etching. Anonymous, ca. 1423."
alt="Engraving of the castle, circa 1423, shows one tower with a tall 
wall around it.">

<img src="castle1858.jpeg" title="Oil-based paint on canvas. Maria Towle,
1858."
alt="The castle as it appeared in 1858, with two towers and two walls.">

<img src="castle1999.jpeg" title="Film photograph. Peter Jankle, 1999."
alt="Photograph from 1999; the castle lies in ruins, only the original 
tower remains intact.">
</figure>

note the added attribute "imgref" for FIGCAPTION -- this is intended to 
provide a strong binding between the individual components of the 
illustration and the caption which describes the images as a group -- 
this is a space delimited list

note that the @imgref attribute is part of the "Structure Guidelines for
DAISY/NISO":

http://www.daisy.org/z3986/structure/archive-SG-DAISY2005/part2-image.htm

note, also that the DAISY structure guidelines also uses an attribute
named "prodnote"

QUOTE 
multiple <prodnote>s if different versions are needed for different media 
(e.g., large print, braille, or print). If several <prodnote>s refer to a 
single <img> with id="xxx", each prodnote would have the same <prodnote 
imgref="xxx"> but each <prodnote> would have a different value for the 
showin attribute to control which media it is displayed in. See 
Information Object: Producer's Note in Part II(b): Block Elements. If 
multiple <prodnote>s refer to a group of images, the imgref attribute 
would include the ids of all images in that group, e.g., <prodnote 
imgref="id1 id2 id3 ...">.
UNQUOTE

in this model, the imgref attribute is applicable to both the FIGCAPTION
and the PRODNOTE (which can be "viewed" as a block-level longdescription
available on user request or in compliance with user-settings (it has a 
default value of render="optional"); obviously the term "prodnote" 
connotes something different than LONGDESC, but it is a potential model 
as to how to get LONGDESC info into the DOM without a fetch from an 
external resource...

how to approach?  should i first file a bug on image grouping that 
simply states:

PROPOSED BUG
For the purposes of grouping and labelling individual images in a 
compound image (that is, a FIGURE containing multiple IMGs with a 
common FIGCAPTION), it is necessary to introduce a new attribute, 
"imgref", which can be used to associate individual IMG declarations
with a FIGCAPTION, using a space delimited list.

<FIGURE>
<FIGCAPTION imgref="img1 img2 img3">Caption Text for Figure</FIGCAPTION>
<IMG src="img1.png" alt="Alternative text for image 1">
<IMG src="img2.png" alt="Alternative text for image 2">
<IMG src="img3.png" alt="Alternative text for image 3">
</FIGURE>

END PROPOSED BUG

thoughts?  next steps?  gregory.
Received on Monday, 14 June 2010 16:03:58 GMT

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