Re: [NTG-context] Accessibility and Tagged PDFs: Bugs and Feature Requests
Am 05.07.15 um 13:11 schrieb Hans Hagen: On 7/4/2015 6:45 PM, Alan BRASLAU wrote: On Fri, 3 Jul 2015 19:19:58 +0200 Hans Hagen wrote: sure but in the meantime we need to find a way to determine what works and what not, for instance, as i mentioned that context already adds a rolemap 11 0 obj << /ParentTree 12 0 R /K 29 0 R /RoleMap << /sectiontitle /H /section /Sect /sectionnumber /H /document /Div >> /Type /StructTreeRoot >> endobj we have no way to check if that works (so maybe we need to have a page on the wiki with a viewer/functionality matrix) The whole rolemap thing and how Acrobat Pro handles it leaves me somewhat puzzled. Taking https://github.com/asdfjkl/tex-access/blob/master/rolemap.tex and compiling will give the rolemap as Hans described above. Looking at the Tag structure, this seems to be ignored by acrobat (but why?), see https://github.com/asdfjkl/tex-access/blob/master/rolemap.PNG What would be expected is this, right? After all, the rolemap should be interpreted, shouldn't it (mapping /H to /H1 was a mistake of mine, but it doesn't change the fact). https://github.com/asdfjkl/tex-access/blob/master/rolemap2.PNG After changing things manually in the tag editor in acrobat, and saving the pdf again, this is obtained: https://github.com/asdfjkl/tex-access/blob/master/rolemap_edited.pdf Note this: << /RoleMap << /document /Div /sectionnumber /H /sectiontitle /H /section /Sect >> /Type /StructTreeRoot /ParentTree 12 0 R /K 29 0 R >> and also the different structure elements at the start of the pdf... I am lost here... cheers - Dominik ___ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___
Re: [NTG-context] Accessibility and Tagged PDFs: Bugs and Feature Requests
On Wed Jul 1, 18:47:57 CEST 2015, Hans Hagen wrote: >> /Artifact >>BMC >>.. >>EMC > >i'll add the simple variant (i see no need to add properties to >something that is supposed to be ignored anyway) thanks! >> 2.) Images without alternate text: > >i'll pass the label to the tag as alt text > >\externalfigure[t:/sources/cow.pdf][label=whatever] Again, thanks! >> 3.) Tag names of the resulting tag structure: >> Section 14.8.4 of [1] defines standard structure types, > >The set of those standard tags is rather limited and imo one of the >craziest things in pdf as we then end up with abuse of those html tags >(and probably endless discussions on what to map onto what). I don't >even have a clue what it would add to the concept either. Reflow is a >braindead thing anyway. Indeed, the set of those tags is very limited. Unfortunately, as far as I know, some screen readers (for the visually impaired) use these as navigation aids, i.e. press button "jump to next section", and the reader will look for the next section marked as or something. Is it difficult to make the mapping user-defineable in the source tex-file? Say, like such a command: \definemapping[ section=Sect, sectiontitle=H sectionnumber=H, ... tablerow=TR ... ] It would then give users the control on what to map onto what, depending on what kind of documents they create. >> All in all, these seem to be the only issues that prevent accessible PDF >> documents with context. For those within an organization where >> accessibility is required legally for all publications, compliance to at >> least Acrobat Pro's checks is a huge issue. I do not know how difficult >> these things are to implement in Context (personally I am just lost in >> the code), but looking at e.g. tex.stackexchange >> for question related to accessibility, this is indeed a major obstacle >> for several people. > >In fact adding pdf tagging to context was rather easy. Some time was >So, it's not that difficult to add features, more a matter of priorities >and motivation (apart from the fact that my acrobat is a bit old by now >so I cannot really test). I can fully understand that such things are not of the highest priority. Nevertheless accessibility plays more and more a role, e.g. lately, even conferences like http://chi2015.acm.org/authors/guide-to-an-accessible-submission/ require accessible pdfs (the workflow they suggest, i.e. tagging a pdf by acrobat pro after compiling of course doesn't work at all - the generated structure is useless). Hence, for some users, it makes all the difference. For example for me and some other friends, it would allow to change from using Microsoft Word to a ConTeXt based workflow. cheers - Dominik ___ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___
Re: [NTG-context] Accessibility and Tagged PDFs: Bugs and Feature Requests
on Tue Jun 30 10:32:29 CEST 2015 luigi scarso wrote: > It would be nice to have a pdf made by context using \nopdfcompression > that have all these issues together with the report emitted by acrobat. Nice idea. The document: https://github.com/asdfjkl/tex-access/blob/master/document_acc.tex Resulting pdf (with \nocompression): https://github.com/asdfjkl/tex-access/blob/master/document_acc.pdf Report of Acrobat 9 Pro (Menu Advanced -> Accessibility -> Full Check...) https://github.com/asdfjkl/tex-access/blob/master/document_acc_AdobePDF.html Note that my goal was not to achieve compatibility w.r.t. pdf/a, I solely focused on accessibility (even though they may be related). Could be very well that I overlooked something, and some functionality is already there with context... cheers - Dominik ___ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___
[NTG-context] Accessibility and Tagged PDFs: Bugs and Feature Requests
Context is the only Tex-based system that allows to properly tag a pdf.
Tagged PDFs are one major requirement for accessibility.
Indeed, in several large organizations/universities, accessibility is
mandated by law, and this is a major obstacle for using Tex. In practice
compliance is often assessed with Acrobat Pro's
accessibility checker.
Context produces a nice tag-structure, but there are some minor issues
that prevent compliance to [1], and hence Acrobat Pro complains during
the check. The main issues are:
1.) Elements that are not contained in the structure tree are not marked
as an artifact. Consider this example:
---
\setuptagging[state=start]
\setuppagenumbering
[location=,
alternative=doublesided]
\setupheadertexts
[{Chapter~\getmarking[chapternumber]\hskip1em\getmarking[chapter]}]
[{Header Right}]
[{Header Left}]
[{Chapter~\getmarking[chapternumber]\hskip1em\getmarking[chapter]}]
\setupfootertexts
[Organization Name]
[pagenumber]
[pagenumber]
[Organization Name]
\starttext
\startfrontmatter
something
\stopfrontmatter
\startbodymatter
some more text here
\stopbodymatter
\stoptext
---
Header, footer, pagenumber etc. will not be included in the tag
structure. Of course this makes absolutely sense and is correct, however
according to Section 14.8.2.2.2 of [1], then this content that is not in
the structure tree should be marked as an artifact, i.e.
/Artifact
BMC
..
EMC
or in an advanced way with /Artifact PropertyList where the type of
Artifact can be defined. It would be nice if those elements that are not
included in the tag tree would be marked as artifacts by default. The
same holds for \startelement[ignore] when one wants to explicitly remove
something from the structure tree.
2.) Images without alternate text:
According to Section 14.9.3 of [1], alternate descriptions in human
readable text should be provided for images. It would be really helpful,
if these could be defined in the source tex file, and then automatically
added when creating the object in the structure tree. I.e. it would be
nice to have something like:
\placefigure[top][Image Reference]{Caption}{
\externalfigure[cow.pdf][width=10cm][alternate text = "This images shows
a beautiful cow."]
}
The same holds for formulas: Whereas the mathml-like tagging of Context
is very advanced, sometimes it might be still helpful to supply a
textual description (alt-text ="The definition of the Pythagorean
theorem: a^2 + b^2 = c^2")
3.) Tag names of the resulting tag structure:
Section 14.8.4 of [1] defines standard structure types, such as ,
, etc. Context creates a tag-tree that uses names directly
representing the structure names of the context laguage, such as
. This should however be mapped to something standard,
such as . Interestingly these mappings seem to have been considered
in strc-tag.mkiv but I was unable to generate such a tagged pdf.
Editing/Outcommenting things in strc-tag.mkiv didn't work for me. It
would be nice if there was a switch somewhere, i.e.
\setuptagging[state=start,tagnames=pdf17] - or maybe I overlooked something?
4.) Acrobat Pro always complains that the language for the whole
document is not set.
5.) Tables
The generated structure looks something like this:
...
...
Here, not only are the tag names non-compliant, also the tag structure
should distinguish between the table header (THead), and table rows
(TBody), c.f. Section 14.8.4.3.1 of [1]. A simple heuristic would be
to always put the first line into THead tags, and the rest of the able
into TBody.
6.) It would be nice if a flat tag structure could be created
optionally. This is not a required feature according to [1], and in fact
a properly nested structure is surely preferable for the final output;
for debugging or checking during document creation however, a flat
structure tree sometimes is easier to browse through.
All in all, these seem to be the only issues that prevent accessible PDF
documents with context. For those within an organization where
accessibility is required legally for all publications, compliance to at
least Acrobat Pro's checks is a huge issue. I do not know how difficult
these things are to implement in Context (personally I am just lost in
the code), but looking at e.g. tex.stackexchange
for question related to accessibility, this is indeed a major obstacle
for several people.
cheers
- Dominik
[1] ISO 32000-1:2008, available at
http://www.adobe.com/devnet/pdf/pdf_reference.html
___
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Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
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