portability/packaging of rich image descriptions...

I'm interested in enabling the portability, reuse and post-production crowdsourcing of rich image descriptions.  

While SVG supports portable and embedded descriptions via the <desc> element, descriptions are limited to plain text, unlike when using longdesc or aria-describedat.  Plain text descriptions are typically not sufficient for information rich images (e.g., infographics or images in used in STEM), do not provide any semantics that are useful when the user wants to provide multiple variations of images and do not support links to alternative versions of images (e.g., versions more suitable for tactile printing)

The portability offered by the <desc> element is particularly powerful, because SVG's <image> element can enable packaging descriptions with non-SVG image formats.

As a portability alternative to the <desc> element, Doug Schepers and I have been discussing building off SVG foreignObjects, however they are not well supported by AT.  Another approach not supported by AT is to use foreign namespaces, which can be used with <desc>:

http://www.w3.org/TR/SVG/extend.html#ForeignNamespaces

In this case, I could use the DIAGRAM image description content model:

http://diagramcenter.org/standards-and-practices/content-model.html

I pasted an example below my signature.  To test this concept we could try to build a JavaScript polyfill that extracts the rich description information from the SVG and makes it accessible to the end user and AT.

I look forward to discussing further, particularly while here at TPAC, so ping me if you want to discuss.

Cheers,

Gerardo
<?xml version="1.0" standalone="yes"?>
<svg width="4in" height="3in" version="1.1"
     xmlns = 'http://www.w3.org/2000/svg'>
  <desc>
	<d:description xml:id="watercycle-desc" xml:lang="en"
		xmlns="http://www.daisy.org/ns/z3986/authoring/"
		xmlns:d="http://www.daisy.org/ns/z3986/authoring/features/description/">
		<d:head>
			<meta rel="z3986:profile" resource="http://www.daisy.org/z3986/2011/auth/profiles/description/0.1">
				<meta property="z3986:name" content="description"/>
				<meta property="z3986:version" content="0.1"/>
			</meta>
		
			<meta property="dc:identifier" content="source-or-self-identification?" />
			<meta property="dc:language" content="en-US" />
			<meta property="diagram:purpose">Illustrates the process of evaporation and precipitation and the natural purification of water.</meta>
		
			<meta property="diagram:targetAge" content="9-12" />
			<meta property="diagram:targetGrade" content="4-7" />
			<meta property="dc:audience" content="all" />
			<meta property="diagram:descriptionQuality" content="7" />
		
			<meta property="dc:creator" xml:id="author01">John Doe</meta>
			<meta about="author01" property="diagram:credentials">Ph.D. in Water Engineering</meta>
		
			<meta property="dc:rights" content="???" />
			<meta property="dc:accessRights">This resource is for use by academic institutions only.</meta>
		
			<meta rel="diagram:currentVersion" resource="http://example.com/science/k12/water/cycle/current"/>
			<meta rel="diagram:thisVersion" resource="http://example.com/science/k12/water/cycle/1.2/description.xml"/>
			<meta rel="diagram:previousVersion" resource="http://example.com/science/k12/water/cycle/1.1/description.xml"/>
		
			<meta rel="diagram:alternateVersion" xml:id="alternateVersion01" resource="http://example.com/physics/k12/water/purification/current">
				<meta property="dc:description">This description provides the science behind the desalination and purification of water using the same cycle sequence.</meta>
			</meta>
		
			<meta rel="diagram:repository" resource="http://example.com/diagram/repository/">
				<meta property="diagram:queryConcept" content="evaporation"/>
				<meta property="diagram:queryConcept" content="precipitation"/>
				<meta property="diagram:queryConcept" content="water purification"/>
			</meta>
		
		</d:head>
		<d:body>
			<d:summary xml:id="summary">
				<p>The image depicts the cycle of water evaporating, turning into clouds, falling back to earth in the form of precipitation and being filtered through sediment.</p>
			</d:summary>
			<d:longdesc xml:id="longdesc01">
				<p>The image depicts the natural process of evaporation and precipitation and how rain water gets filtered and cleansed through the earth's sediment.</p>
				<p>On the left-hand side of the image is a lake...</p>
				<p>A weather event such as a rainstorm eventually returns the precipitation to the ground...</p>
				<p>The natural filtering agents in the soil...</p>
			</d:longdesc>
			<annotation ref="longdesc01" role="diagram:comment" by="teacher">
				<p>In the winter we get snow instead of rain.</p>
			</annotation>
			<d:simpledesc xml:id="simpledesc01">
				<p>The image show how water becomes clouds, then rain, and then gets cleaned by the soil.</p>
			</d:simpledesc>
			<d:tactile xml:id="tactile01">
				<object src="http://example.com/tactiles/repository/water-cycle.svg" srctype="image/svg+xml"/>
				<d:tour>
					<p>In the upper left corner of the tactile…</p>
				</d:tour>
			</d:tactile>
			<d:altImage xml:id="alt-image">
				<object audience="low-vision" src="http://example.com/…/evaporation-lv.svg" srctype="image/svg+xml"/>
				<d:tour>
					<p>Moving front the top left corner of the image…</p>
				</d:tour>
			</d:altImage>
		</d:body>
	</d:description>
  </desc>
  <!-- In here would be the actual SVG graphics elements which
       draw the pie chart -->
</svg>


Gerardo Capiel
VP of Engineering
benetech

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