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Re: More on 3.4

From: Matt May <mcmay@bestkungfu.com>
Date: Wed, 1 Aug 2001 15:58:46 -0700
Message-ID: <045201c11add$94e932d0$6501a8c0@vaio>
To: "Charles McCathieNevile" <charles@w3.org>
Cc: <w3c-wai-gl@w3.org>

----- Original Message -----
From: "Charles McCathieNevile" <charles@w3.org>
>   old MM  It's a technical limitation of GIFs and JPEGs that metadata
can't be
>   stored within, which is why alt text is tied into the HTML anchor.
> This is not true. For a set of tools that actually does include metadata
> within JPEG images see the W3C Note Describing and retrieving photos using
> RDF and HTTP (28 September 2000, by Yves Lafon, and Bert Bos) at
> http://www.w3.org/TR/photo-rdf/

I'm familiar with techniques in steganography to add data in lossy
compression algorithms, and also built-in capabilities in the GIF format to
add comments. I would have been more accurate in saying that metadata is not
commonly stored in images, and the tools to create, manipulate or view the
images don't provide a standard mechanism for doing so, which limits the
ability for images to self-identify in metadata, thus requiring the alt

> CMN Agreed. I am very strongly with you on the idea that there is no
> ratio" or quantitative level assessment that we can usefully set as a firm
> rule. So I am arguing that in some cases content should be supplemented -
> example, recorded speech should be supplemented with a textual record of
> is said (and, I would argue, signed captions in appropriate languages,
> especially for complex content), graphics should be supplemented with text
> descriptions, and text, should be supplemented with pictures, sounds, and
> on, to ensure accessibility of the content to as many people as we can

I don't disagree with anything you're saying here. I may even agree with you
on a great number of the "some cases" in which supplemental content is
beneficial. I just don't see where success criteria are discoverable, or
techniques can be broad enough to be effective.

I've said before that there needs to be a non-normative document or
documents for accessible web design, and even that it should be required
reading. It's stuff like 3.3 and 3.4 that's continuing to lead me to believe
that the idea still has merit.

> CMN Many current Web authors do not have the ability to work on source
> That is not a job that can be done by semi-skilled labour, it requires
> particular training that is not the same as the training that people who
> producing content actually have.

Where I live, HTML-only authors are considered semi-skilled labor. Anyway,
many new repair tools can be used by those who don't know HTML (for which we
have ATAG to thank). But those HTML workers and people interacting with
accessibility tools won't be able to do anything for 3.4, that I can detect.
It's out of scope for either group.

Received on Wednesday, 1 August 2001 18:59:14 UTC

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