[Athen] postscript Accessibility questions

[Dan Comden]

Ghostscript is a utility that will convert postscript files to PDF, though 
in the FAQ, it's noted to do so with "some limitations"

Staff here have used it on occasion to work with math image files, though 
I don't have much direct experience with it.

http://www.cs.wisc.edu/~ghost/
and
http://www.ghostscript.com/awki
are two places to read more about it

-*- Dan Comden			danc at u.washington.edu
     Access Technology Lab	http://www.washington.edu/computing/atl/
     University of Washington

On Tue, 23 Jan 2007, Sean Keegan wrote:


> Hi Terri,

>

> My understanding is that PostScript is a programming language for describing

> how a page should "look".  PDF, for instance, uses a subset of the

> PostScript language for fonts, etc.  For the most part, PDF has become the

> manner to display print information as opposed to PS.

>

> I am not aware of any assistive tech that "reads" PostScript directly.  You

> could use something like Adobe Illustrator or Photoshop to open a PS file,

> but the result would be the visual rendering of what the PS code says to

> "do".

>

> In terms of processing content for a student, I think you have a bit more

> flexibility with today's PDF technology than with PostScript, but I am going

> to have to defer to others for their thoughts and opinions as I do not have

> much experience with PostScript itself.

>

> Take care,

> Sean

>

>  _____

>

> From: Terri Hedgpeth [mailto:terrih at asu.edu]

> Sent: Tuesday, January 23, 2007 4:23 PM

> To: skeegan at htctu.net; Access Technologists in Higher Education Network

> Subject: RE: [Athen] postscript Accessibility questions

>

>

>

> Sean and all,

>

> What about a post script file? What tool(s) can a student who is blind use

> to convert a post script file into a readable form and maintain the format?

>

> Thanks,

>

> Terri

>

>

>

>

>

> Dr. Terri Hedgpeth

>

> Academic Research Professional

>

> CUbiC #376, iCare

>

> (480) 727-8133 V

>

> (480) 965-1885 Fax

>

> CUbiC.asu.edu

>

> http://www.fulton.asu.edu/fulton/

>

>

>

>  _____

>

> From: athen-bounces at athenpro.org [mailto:athen-bounces at athenpro.org] On

> Behalf Of Sean Keegan

> Sent: Tuesday, January 23, 2007 4:04 PM

> To: 'Access Technologists in Higher Education Network'

> Subject: Re: [Athen] PDF Accessibility questions

>

>

>

> Hi Kathy,

>

>

>

> Thanks for the information.  I wanted to distinguish between following a

> "standard" vs. making the PDF accessible to AT.   I can see your challenge

> not having access to the original documents that may have begun as MS Word

> or other word processing files and then attempting to make everything

> accessible via Adobe Acrobat.

>

>

>

> You can add/remove tags to a PDF document without using the Accessibility

> Checker.

>

> - Open the untagged PDF document.

>

> - Use the Add Tags to Document option (under Advanced > Accessibility)

>

>

>

> If there are already tags for the document, then you will just need to check

> how the content is organized.  I generally do this with the TouchUp Reading

> Order tool.

>

>

>

> - Turn on the TouchUp Reading Order tool (under Advanced > Accessibility)

>

> - Visually scan the document for any major overlaps in content of

> text/equations on the page.  You can rezone the content using the reading

> order palette for content vs. equations/images/etc.

>

>

>

> If there are equations, these may be initially represented as "Table" or

> "Figure - No alternative text exists" after adding tags to the PDF document.

> You can reclassify equations as "Formulas" and then go back and add

> alternative text (or leave them classified as Figures and add the

> appropriate text description).

>

>

>

> You can also create tags manually (well, semi-manually) by using the TouchUp

> Reading Order tool on a page-by-page basis.  Content that you zone and then

> set using the reading order palette automatically gets a tag created in the

> Tags tab.

>

>

>

> Hope this helps.  Let me know if you have tried this and it is not working.

>

>

> Take care,

>

> Sean

>

>

>

>  _____

>

> From: Kathleen Cahill [mailto:kcahill at MIT.EDU]

> Sent: Tuesday, January 23, 2007 12:13 PM

> To: skeegan at htctu.net; 'Access Technologists in Higher Education Network'

> Subject: RE: [Athen] PDF Accessibility questions

>

> Hi Shawn;

>

> Let me answer your questions below (my answers are in dark purple -- hope it

> comes through):

>

> -----Original Message-----

> From: athen-bounces at athenpro.org [mailto:athen-bounces at athenpro.org] On

> Behalf Of Sean Keegan

> Sent: Tuesday, January 23, 2007 2:05 PM

> To: 'Access Technologists in Higher Education Network'

> Subject: Re: [Athen] PDF Accessibility questions

>

> Hi Kathy,

>

>> I am working with an MIT department that uses a lot of PDF files and am

>

> trying to help

>

>> them get the "cleanest" PDF files possible.

>

> Not sure if I quite understand what you mean.  Do you mean a PDF document

>

> that is "tagged" according to a certain specification or do you mean a PDF

>

> document that works with assistive computer technology (or a bit of both)?

>

> My answer:  I mean a PDF document that is tagged in Acrobat so it will work

> better with AT.

>

>> Sometimes, after running the accessibility check, I get an error message

>

> that "Acrobat

>

>> was unable to make this document accessible because it could not save page

>

> structure

>

>> (incorrect structure was found in PDF file).  Could not save changes."

>

> Have you ever

>

>> received a similar message and what did you do?

>

> I am assuming that you are referring to the Accessibility Checker in AA 7.

>

> The short answer is that I tend to avoid using the accessibility checker -

>

> yes, it has gotten better, but it still gives a lot of "You may need to

>

> check this" type responses.  Also, you can get messages like "Provide

>

> Missing Unicode Encodings" and this cannot be fixed from within AA - not

>

> very helpful.

>

> I prefer to save the PDF document as a Text (Accessible) file and then open

>

> the file in a text editor/word processor.  I spot check the document as to

>

> where I have concerns with the reading order of the content.  Content that a

>

> screen-reader may interpret will be identified in brackets "[ ]".

>

> Kathy's answer: That probably won't work very well if I can't use the

> accessibility checker in Adobe Acrobat 7.0.  Many of these documents have

> math notation in them.  I realize that screen readers will not read the math

> and science notation but if I'm trying to also apply some structure to the

> PDF, I don't know how else do that in Acrobat unless I use the accessibility

> checker.  I don't have access to the source documents for these PDFs.

>

>> 2.  After running an accessibility check, sometimes I get a message that

>

> "there are x > number of words with characters that do not map to Unicode."

>

> ....Any possible

>

>> solutions or suggestions on this?

>

> How are you creating your PDF documents?  If I begin in something like MS

>

> Word (or InDesign) and go to PDF, I do not seem to encounter this issue.

>

> Kathy's answer:  Some of the documents were probably created in Matlab or

> Latex, if they have math notation in them.

>

> I suppose I am asking:  What is your workflow for PDF document creation for

>

> both text and math-based documents?

>

> Kathy's answer:  Many of the text-based documents were created in MS Word

> but probably not with structure.

>

>> 3.  I've also gotten error messages that say, "x number of elements were

>

> not contained

>

>> within the structure tree."  Say what?

>

> Wow - very helpful message.  I have gotten this once before where some page

>

> content could not be added to the tagged structure.  It was not text-based,

>

> so that may have been the problem (AA could not identify what it was).

>

> Kathy's comment:  Again, this could be due to math/science notation in the

> document that Acrobat doesn't know what to do with.

>

>> 4.  I've also run OCR on a PDF that looked like it was an image only PDF

>

> with some

>

>> math notation.  When I have run an accessibility check on the allegedly

>

> OCR'ed file,

>

>> the report says there are no problems, which is hardly the case when there

>

> is math

>

>> notation.

>

> Hmmm - I am not sure I understand.  Was there text on the page?  Did that

>

> content get OCR'ed correctly or did nothing get recognized?  Do you have an

>

> example I can play with?

>

> Kathy's comment:  There was text on the page.  It seems like even after

> Paper Capture (OCR) was run in Acrobat, it still retains its characteristics

> of an image-only file.  I will email you the file separately to look at.

>

> It sounds as if you are attempting to create PDF documents containing math

>

> notation AND have these documents be accessible.  I am not aware of any

>

> assistive computer technologies that can read native math equations within a

>

> PDF document.  I know that Design Science was interested in doing some work

>

> on this, but I do not know how far they have progressed.

>

> Kathy's comment:  I realize that screen readers cannot read math content.  I

> am trying to get the text part of the PDF to be as accessible as possible.

> The departments that create these documents are going to need to create

> descriptive ALT tags that go with the math notation to make it meaningful,

> or find some other format.  We are trying to push the departments to

> consider MathML but so far, no takers on a department level.

>

> Thank you for your help,

> Kathy

>

> Take care,

>

> Sean

>

> Sean Keegan

>

> Web Accessibility Instructor

>

> High Tech Center Training Unit of the California Community Colleges

>

>

>

> -----Original Message-----

>

> From: athen-bounces at athenpro.org [mailto:athen-bounces at athenpro.org] On

>

> Behalf Of Kathleen Cahill

>

> Sent: Tuesday, January 23, 2007 8:32 AM

>

> To: 'Access Technologists in Higher Education Network'

>

> Subject: [Athen] PDF Accessibility questions

>

> Dear Colleagues;

>

> I am working with an MIT department that uses a lot of PDF files and am

>

> trying to help them get the "cleanest" PDF files possible.  I would love to

>

> get some feedback from those of you who regularly use the Adobe Acrobat 7.0

>

> accessibility checkers and do lots of tagging and alterations of document

>

> structure.

>

> I have some questions regarding files that originate in Microsoft Office or

>

> Latex format (full of math notation):

>

> 1.  Sometimes, after running the accessibility check, I get an error message

>

> that "Acrobat was unable to make this document accessible because it could

>

> not save page structure (incorrect structure was found in PDF file).  Could

>

> not save changes."  Have you ever received a similar message and what did

>

> you do?

>

> 2.  After running an accessibility check, sometimes I get a message that

>

> "there are x number of words with characters that do not map to Unicode."

>

> Acrobat suggests the user use a different font, recreate the PDF with a

>

> newer version of Distiller or use the latest Adobe Post Script driver to

>

> create a Post Script file, then a new PDF file.  Usually, this error message

>

> come through on a document with lots of math notation.  Any possible

>

> solutions or suggestions on this?

>

> 3.  I've also gotten error messages that say, "x number of elements were not

>

> contained within the structure tree."  Say what?

>

> 4.  I've also run OCR on a PDF that looked like it was an image only PDF

>

> with some math notation.  When I have run an accessibility check on the

>

> allegedly OCR'ed file, the report says there are no problems, which is

>

> hardly the case when there is math notation.

>

> If you have suggestions for me to try or know of any folks at Adobe I can

>

> contact, I'd greatly appreciate it.

>

> Thank you,

>

> Kathy Cahill

>

> **************************

>

> Kathleen Cahill

>

> MIT ATIC (Adaptive Technology) Lab

>

> 77 Mass. Ave. 7-143

>

> Cambridge MA 02139

>

> (617) 253-5111

>

> email: kcahill at mit.edu

>

>

>

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