Alt Texting

From ElateWiki


Alternative text (alt text) refers to the addition of information-rich descriptors to capture the informational value of a digital image (a photo, a diagram, a map), for learners who may have visual acuity issues. Alt text is required as part of accessibility based on Section 508 of the Americans with Disabilities Act (http://www.section508.gov/). These standards describe the importance of tagging images with alt text: "Generally, this means use of text labels or descriptors for graphics and certain format elements. (HTML code already provides an "Alt Text" tag for graphics which can serve as a verbal descriptor for graphics). This section also addresses the usability of multimedia presentations, image maps, style sheets, scripting languages, applets and plug-ins, and electronic forms." (http://www.section508.gov/index.cfm?FuseAction=Content&ID=11)

Contents

The Functions of Alt Text

Alternative text captures the informational value of a particular image albeit in word form (full sentences). Alt text labels the image. It describes its contents. It captures the origins of the image. It also may include photo credit or ownership information.

Imagery may involve photos, diagrams, blueprints, maps, tables (as images), charts, and other visual elements.

Captioning

Captioning refers to the additional elements describing an image beyond the alt text. Captioning often links an image to the rest of the text in which the image is a part (if it is integrated).

Where the Alt Text Goes

The alt text has a special location where it is placed...in HTML and in digital imagery in digital files. In HTML, there is a segment for alt text where an image is embedded.

Right-click an image in a Microsoft Suite document and go to Size / Alt Text...to get the form field to put the text there.

Alt-texting may also be built directly into the code of a page, through XHTML. The descriptions here tend to be very brief phrases. More extended alt-texts are marked up differently in XHTML as long descriptions or "longdesc".

Downloading Images with the Alt Text Intact

When taking public domain images off of a site, one can drag it off the site, and that seems to keep the image's alt text intact. Doing a "Save Image As" from a site after right-clicking on the image seems to lose the alt text on some sites.

See Also

"Alternative Text for Images" (Wikipedia): http://en.wikipedia.org/wiki/Wikipedia:Alternate_text_for_images

References