Problems With Bookmarks/Anchors in Word-PDF Conversion, and "Alt" Text for Images

September 6, 2004 6:54 AM

PDF question about named destinations, text touchup tool and "alt text" for images. (More inside)

Hours have been spent googlng, to no avail: We have large source Word documents with bookmarks set up for internal nav. When converted to pdf, those bookmarks metamorphose into some kind of internal nav points, but if we try to link to them from html (www.page.com/document.pdf#place) it won't work. Anyone know why?

So, to get round that, we laboriously define named destinations in Acrobat Standard v6.0. That is time-consuming, but worls. However, if there is a small change, or a typo, we have trouble: going back to the source document means manually re-doing all the named destinations again. But changing one character (eg "Associatoin" to "Association") with the text touch-up tools adds between 40 and 90K to the file size! Anyone know how to stop this massive bloating?

Finally, where oh where do we add "alt-text" to pictures in the pdf for screen readers?

posted by Pericles to computers & internet (3 comments total)

can't answer most of that, but can guess at the explanation for file growth. pdf is much more like a programming language than a mark-up language (think javascript rather than html). so a touch-up tool probably has to "run" the program (evaluate the document) and make changes to the result before generating a new program that reproduces that. so it's not just changing a small amount of data and it's unlikely to be as efficient as the original program (which knew much more about the document).

you'd be better finding a way to script the addition of named destinations so that you can do minor edits to the original.
posted by andrew cooke at 9:02 AM on September 6, 2004

Your link syntax is incorrect. In fact, you need to use #page=pagenumber. To link to a named anchor, use #nameddest=destination_string. See Linking to Specific Pages in a PDF File (or just Google that very phrase).

Now, for alt texts, the easiest way is to add them in the image properties in Word. If you need to add them later, you have to Add Tags to Document in Acrobat, then laboriously find the Figure element in question in the Tags Inspector, select it, then select Properties, and type in the alt text there.

If you are exporting from Word 2000 and later on Windows with the toolbar button that Acrobat installs, it will have produced a tagged PDF for you already, in which case you can just locate the Figure element in the Tags palette and add the alt text; skip the adding-tags step, since they're already there.

Don't suppose there is an example file online that we can look at?
posted by joeclark at 9:13 AM on September 6, 2004

Saving changes to a PDF file tacks your changes onto the end. It's related to how digital signatures work in PDF, and how you can always revert to a signed version even if you've changed it and invalidated the signature. If you want to rewrite the whole file with your minor changes included, pick "Save As..." instead of "Save."
posted by mdeatherage at 9:29 AM on September 6, 2004