[NTG-context] Re: Images and Accessibility (ConTeXt LMTX 2025.04.28)

Hi Pablo, I was merely reporting what Previews and Acrobat on the Mac do with the current image accessibility provided by ConTeXt. I have no idea whether that is enough for vision-impaired people. It might be that there are screen readers available that do a perfect job. At some point I will need to produce documents that are accessible. For that my documents will have to pass a test (to which I don’t have access before submitting the document…). I have no idea whether “passing the test” means that the document is usable for someone with vision impairment. Of course I would like that to be the case, too, but my abilities to test for any of that are limited. I tried the first page from https://www.recht.bund.de/bgbl/1/2025/104/regelungstext.pdf?__blob=publicationFile&v=3?. It passes Acrobat’s accessibility check, hovering over the image produces the alternate text, letting Acrobat read the document ignores the Bundesadler. When I use VoiceOver in Preview, it detects the image group and speaks the alternate text. But VoiceOver does not seem to be able to read the rest of the page. When, on the other hand, I let Preview read the entire page, it ignores the Bundesadler. What would help is if someone with access to a screen reader like JAWS or NVDA can report what it does with the compiled example in ConTexT. I am having similar issues with having formulas read on the Mac. I can see the XML attachments in Acrobat, but what Acrobat or Preview do with them is horrendous. And as for my final comment about the “only benefit”: It seems to me that the two programs I tried on the Mac are bringing no benefit to the vision-impaired. That’s said, but nothing ConTeXt can help with. It just makes everything more complicated, because I have no means of telling whether what I am trying to do to make documents accessible is effective in any way. Matthias

On Apr 29, 2025, at 3:20 PM, Pablo Rodriguez via ntg-context wrote:

On 4/29/25 19:13, Matthias Weber wrote:

...

Dear All,

I am starting a new thread as requested.

Hi Matthias,

...

I can confirm that [...] produces a PDF that passes the accessibility check in the current> Adobe Acrobat. In particular, it passes the alternate text checks. Hovering over the image shows the alternate text in Acrobat.

I think that alternate texts are primarily intended to be read aloud.

In fact, the older PDF specification (the only one publicly avaiblable) describes them as (third row from https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/PDF32000_2008....):

An alternate description of the structure element and its children in human-readable form, which is useful when extracting the document’s contents in support of accessibility to users with disabilities or for other purposes.

Displaying the alternate text when hovering the image is not in support of accessibility (I think), but just for other purposes.

...

However, VoiceOver (on the Mac) does not read the alternate text; it completely ignores the existence of the image.

In Preview, no alternate text is shown or read. So it seems that the> only benefit is that readers with vision can see an alternate text...

Sorry, could it be possible that both programs might not comply with accessibility as PDF requires it?

Or do both programs read aloud the alternative text for the »Bundesadler« from https://www.recht.bund.de/bgbl/1/2025/104/regelungstext.pdf?__blob=publicationFile&v=3?

Your final comment on the only benefit is not clear to me. Visually-impaired living beings (not especially humans) may find easier listening to sound or voices than seeing in general.

...

I don’t have access to a Windows machine, so I cannot test what other screen readers can do with this document.

I think the Accessibility Directive requires reading programs to comply by making them accessible (sorry, bad wording, but I guess it is clear what I mean [let me know if it is not]).

I hope it helps,

Pablo ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki!

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