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When "Alt" is not the semantically-correct representation of an image


From: Duff Johnson
Date: Jul 26, 2018 4:03PM


I've searched HTML / ARIA / WCAG documentation for a solution to this problem with no joy. Hopefully I'm just missing something.

USE CASE: Graphical content (typically, an image, but it could be SVG, etc.) representing text for which the text is the semantic content. Another way to put it: cases where the content's semantics do not match its encoding.

It's the same problem as text art (text content representing images), but in the opposite direction (content encoded as images but representing text).

Examples include:

- Stylized text (e.g., text that has been converted to an image for use as a stylized heading). Think of a classic "ransom note" style - that is, phrases made from words that have been cut from a newspaper.

- Scanned documents converted to HTML in which OCR "suspects" are retained as small inline images

- Illuminated characters

- Ligatures

- Cases in which the usage implies representation of the "actual" text rather than descriptive "alt" text. Such a case might be the use of organization logos inline in a sentence. Example: "How [Accenture logo] reduces risks." In this case, the Accenture logo should clearly be represented to AT as "Accenture" for the purposes of reading the sentence - otherwise a reader might get the impression that use of the Accenture LOGO itself can "reduce risks", which is unlikely to be what the author was trying to imply.

In PDF we have a concept of "ActualText" which meets this need. In fact, in PDF a Figure structure element can possess both "Alt" _and_ "ActualText" values. Ideally AT would be able to represent either/both as appropriate.

But for now my question is: what's the accessible HTML thing to do in such cases? It seems to me as if HTML's model just doesn't adequately address such cases at all; that's where I'd like to hear some input.


Duff Johnson

Independent Consultant
PDF Association Executive Director
ISO 32000 (PDF) Intl. Project Co-Leader & US Chair
ISO 14289 (PDF/UA) Intl. Project Leader & US Chair

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