EPUB 3 Working Group FXL A11y Task Force Telco — Minutes

Date: 2021-06-22

See also the Agenda and the IRC Log


Present: Wendy Reid, Gregorio Pellegrino, Matthew Chan, Laura Brady, Avneesh Singh, Charles LaPierre, Brady Duga, Hadrien Gardeur, Matt Garrish



Chair: Wendy Reid

Scribe(s): Matthew Chan


Wendy Reid: are there any updates on the projects people have taken on?
… Rachel_Osolen has sent info on a11y comics

Gregorio Pellegrino: i went through parts of the epub spec and found some interesting things that might help create some fxl epubs
… one is the element collection inside the manifest that allows you to group parts of elements in metadata for describing content inside the epub
… maybe this could allow us to group FXL content with non-FXL content
… the other is when we have 2-pages with a single image across the spread
… for FXL you can set the property page-spread-center
… this sets the single content across both pages
… so authors can instead use a single page of HTML content with this property set

Wendy Reid: page-spread-center is partially supported

Gregorio Pellegrino: https://www.w3.org/TR/epub-33/#page-spread

Wendy Reid: but it isn’t necessarily used for spreads across two pages, because a lot of RSes don’t respond well when FXLs contain pages with different viewport sizes

Gregorio Pellegrino: https://www.w3.org/TR/epub-33/#sec-collection-elem

Wendy Reid: not universal behaviour, but that is a possible roadblock to using that technique

Gregorio Pellegrino:rendition:page-spread-center property indicates to override the synthetic spread mode and render a single viewport positioned at the center of the screen.”

Hadrien Gardeur: on collection, this was used to group together a number of resources and say something about them
… e.g., in education space, to have sub-units of a publication that could be distributed together, or have a semantic meaning together
… i.e., introducing the ability to create logical groups at the spine level
… but since it was mostly an EDUPUB thing, it is not highly implemented

Wendy Reid: we also talked about the alt-text section of the documentation

Charles LaPierre: we did a branch of the doc, and started adding some basics in there. Once we are ready for group review we’ll do a PR

Avneesh Singh: administrative concern: is the alt-text we are talking about specific to epub? If not, then we normally have a CG do this sort of work if it isn’t specific to a particular spec

Wendy Reid: this is specific to only FXL epub

Charles LaPierre: we’re thinking of having a sample FXL with examples of how someone might write alt-text for it, but in the resources section we just have some generic alt-text guides for now

Ken Jones: re: the 2-page spreads and Rachel_Osolen’s a11y comic book email, a number of months ago I opened an issue in a DAISY repo to ask about describing 2-page spreads, and also spreads with photo montages

Ken Jones: https://github.com/daisy/kb/issues/35

Ken Jones: in those instances, could we tile the areas of the spread, so that we can attach alt-text to those tiles?
… as a way of locating the alt-text within the spread, and for reading order purposes
… one way I was thinking of doing that was to have an invisible object that we could attach alt-text to, that we could then drop into the reading order
… this would present an obstacle to any technique that would transform a visual view to a textual view

Matt Garrish: not sure about invisible objects because that assumes the viewer can’t see the image at all

Wendy Reid: we did previously discuss the idea of using mappable regions for this purpose

Matt Garrish: right, better to try to build off existing technologies, and if that doesn’t work, then we can take it back to a wider group

Charles LaPierre: so in the case of a comic book with speech bubbles, sometimes in a small scripted font, for low-vision users this isn’t good
… and zooming in results in pixelation
… the idea of zoning, plus being able to toggle user-defined fonts, font sizes, etc.
… is that something that we can tackle in this group, or does it need to be run up to a higher level of W3C?

Wendy Reid: zoning is something we might already have existing web tech for

Brady Duga: we’ve basically implemented the text features you mentioned, but we ran into limitations: available space, overlapping
… but they’re surmountable problems. We did end up implementing

Ken Jones: https://paper.dropbox.com/doc/Visual-to-Textual-Explainer–BNIYen9D3PBflNmBs6yax4JJAg-K3nAwKn2vlVqRpFyZ9KHN

Wendy Reid: Ken wrote an explainer about the idea of potentially turning FXL into reflow via a process
… this bleeds into changing epub to do something new, so we might want to bring this to the wider W3C
… what we might potentially need is a way to signal to RS that a single FXL contains both FXL and reflow modes, and that user should have the ability to switch between
… but we still have to think about what to do about images, audio, etc. in the reflow

Brady Duga: the problem i’m having trouble seeing the solution to is how to merge pages, e.g. where information like a paragraph is split across a page

Hadrien Gardeur: if we look at what has been tried in the past, there was the idea that regions across a spread could be mapped to IDs. With regard to how it looks, it depends on whether it is authored or not
… if it is authored, both could look good. We just have to figure out the mapping question
… of course, it is a lot of extra work

Ken Jones: i put in a section on page breaking, in which i proposed that we say when a page break is wanted in the reflow document
… otherwise, the pages would run sequentially
… also, a lot of FXLs are designed to break cleanly across pages, so I’d have to see a problem example to know what to do

Hadrien Gardeur: one question we need to ask is whether we’d be happy enough to be able to indicate a reflow equivalent, maybe on a spread-by-spread basis
… not to get too far back into multiple-renditions
… maybe we leave the idea of mapping individual fragments of a document for a later time

Wendy Reid: and I don’t want to fixate on this one issue and have it block our progress
… if we can get it working to where we can get a reflowable version of an FXL, then I would consider that iteration 1 complete
… would love it if everyone could read over Ken_Jones’s document, and think about the problems presented, and come up with some solutions for them
… and while you are doing so, please keep in mind that the webbier the better (i.e. reusing existing tech)

Avneesh Singh: Conceptually I very much like the idea of converting fixed layout to reflowable.

Ken Jones: shall we make a list of existing issues?

Wendy Reid: your document has “advice required” tags, so those are a good start.
… But yes, 1) what to do about images, children’s books where images are most of the content, 2) other media content (audio, video), maybe via media queries?

Hadrien Gardeur: media queries is also problematic because it might be something that the RS doesn’t have access to
… might be better to rely upon things that we already know are implemented in epub

Wendy Reid: another problem is how to deal with text styling/alternate style sheets

Ken Jones: is there documentation on alternate style sheets?

Wendy Reid: yes, its part of the HTML spec

Wendy Reid: https://developer.mozilla.org/en-US/docs/Web/CSS/Alternative_style_sheets

Gregorio Pellegrino: they are similar to media queries, and you have keywords to tell UA to use the alternate style sheet
… there are other keywords, e.g. to render the document in alternative colors, or with a magnifier, greyscale, black and white
… we’d have to check which of those keywords are supported or not. It is not universal.

Ken Jones: so this would be chosen by the user before they open the FXL?

Matt Garrish: there are 3 ways to get alternate style sheets. 1) Just have additional style sheets, 2) the media query type way, and 3) the epub specific alternate styles

Brady Duga: the epub specific alternate styles are rarely implemented. I would discourage.
… and I think it would be fine for users to switch style sheets mid-reading. Whether or not that works well is really down to the RS

Gregorio Pellegrino: CSS media query: https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries/Using_media_queries

Charles LaPierre: couldn’t there be js hooked up to a button that changes the style sheet?

Brady Duga: not sure that gets you what you want, because you want the RS to do a bunch of things differently, like enable pagination etc.

Hadrien Gardeur: also any js could be blocked by the RS for a number of different reasons. We’re not on the web, after all (and even if we were on the web)
… no matter which technique we use, there is also the problem of completeness
… the other challenge is that if we want user to be able to switch between these, then it becomes a UX problem
… better if this feature is known to the RS, and then the RS could help you select it

Wendy Reid: for next call, everyone please read Ken_Jones’s explainer doc and try to come up with some solutions. Don’t have to have complete solutions. Just suggestions is okay

Hadrien Gardeur: have we explored the possibility of solutions based on multiple OPFs?
… especially if we’re setting aside the issue of how to handle fragments of content

Wendy Reid: no. The biggest change we’ve considered is adding another meta property to say that “this is a visual to textual epub”. With maybe something to signal multiple style sheets. We want to stay away from multiple-renditions and multiple packages

Hadrien Gardeur: fallbacks?

Wendy Reid: not really, not sure about level of implementation

Gregorio Pellegrino: about fallbacks, what would trigger those fallbacks? Normally the trigger is automatic, i.e. when the RS can’t do something the epub wants it to do

Hadrien Gardeur: so media type is one thing you can fallback on, but also the idea that you could move between resources if different languages, or even if one resource is FXL and other is reflowable
… i.e. the core idea of multiple renditions, but without the implementation cost of having multiple packages

Brady Duga: i don’t think fallbacks are off the table. We should continue to consider them. But my big concern is potentially conflicting fallback chains

Hadrien Gardeur: and maybe fallback is not the right term in this case. In Readium we have the concept of alternates, and you can say that “this alternate is available in… different media type, resolution, etc.”
… and what you trying to do is maybe define concept of alternates at the spine level
… potentially giving us the benefits of multiple renditions without the complications

Wendy Reid: main obstacle to fallbacks is that they are under implemented right now, but maybe this gives new reason for RS to enable fallbacks
… is it worth building a tiny sample of this textual to visual technique?

Ken Jones: happy to do that? Shall I prioritize this before I write the next section of the doc?

Wendy Reid: yes, it doesn’t need to be a huge example, even 1 page

Gregorio Pellegrino: along with the example, maybe we could have a mock-up of what it would behave like (e.g. maybe running in a browser or something)

Ken Jones: i was going to just have two different documents, to show what the textual version would look like, and what the visual version would look like
… i’ve also been invited to prepare a short video/presentation on a11y FXL
… should I just give them an overview of the topics we’ve discussed?

Wendy Reid: the idea behind the videos is just to communicate to the community what we’ve been doing behind the scenes
… so the best practices document, the idea of visual to textual. It should be very high level.
… maybe you can just show us a bullet point list of what you’re planning to include