4 Replies Latest reply on Jul 10, 2014 5:27 AM by evansreb

    What is the best way to preserve page numbers from InDesign to EPUB?

    CogniA Level 1

      I have a project where the source files are InDesign based - the final step before the product goes to print.  We want to bring this content to reflowable EPUB format, but we need to keep the print page numbers in order to support citations.


      Has anyone faced this type of challenge previously, and what was the approach pursued?  While an InDesign 2014 export to EPUB Fixed will preserve the page numbers, there will be a lot of cleanup required to make these files reflowable again.



        • 1. Re: What is the best way to preserve page numbers from InDesign to EPUB?
          Douglas.Waterfall Adobe Employee

          Can you explain this a bit more?


          We have heard requests that we maintain what is called the "page-list" which allows a relationship between the print page and points in the reflowable document but I'm not sure if that is what you're talking about.


          We have also heard requests to support hyperlinks to pages (instead of dropping them) which in some sense is the same thing.


          Most good practices with regard to print->reflowable is to eliminate the page numbers entirely because they are misleading - print page != relflowable page.


          Douglas Waterfall

          Architect, InDesign Engineering

          • 2. Re: What is the best way to preserve page numbers from InDesign to EPUB?
            CogniA Level 1

            Hi Douglas,


            I agree that the common practice of removing the page numbers works with regards to trade content (fiction, non-fiction, magazines, etc) where pages generally are to communicate how far you have 'travelled' in a particular title.  With reference works, however, this particular type of metadata can have a greater meaning - communicating to other individuals the location of a reference in order to allow them to see the reference in its original context.  It becomes a way of locating relatively precise locations within a work that is being referenced.


            Currently, and we can expect for some time, the original print content will be the authoritative version that is referred to, or cited, as a means of communicating the exact location of a specific reference to another individual.  Although evident in many industries, perhaps this arises most commonly in legal texts, where a lawyer as part of an argument or a judge in writing a decision will cite a text reference by title, volume, possibly edition, date/year, etc. and, ultimately, the page number - which in the end is just another piece of metadata relative to the text that appears on that particular page.  In order to create digital copies of these types of texts that can still function relative to the print authority, an accurate page number that corresponds to the print needs to be available somewhere in the texts.  (This is true both ways, by the way - both in terms of following a cite to a specific location within the content; and citing a specific location within the content).


            For many publishers, InDesign will be the final, what I would call 'exportable' format that can maintain a certain degree of information about the context of the source content and will have page numbers represented that precisely reflect what will be found in the final print version.


            I have some ideas on how I would like to present this in a reflowable digital version (and reflowable text for this type of content is desirable for all the reasons it would be elsewhere - adaptability to screen size, ability to resize/change fonts for different reader experience, etc). And the new EPUB fixed export function will allow me to preserve the page numbers and through some programming I can get to a point where I can isolate the text that corresponds to a specific page number from the InDesign exporta manual solution would not be an improvement), but with a somewhat 'cleaner' export of the text of the content, where the precise fixed formatting is not so important.


            The perfect solution would be to allow page numbers to be preserved within a 'hidden' tag in the EPUB reflowable export - so that the content of each page would be preceeded by an <a id="Page_75" /> tag, with words that are hyphenated belonging to the page on which they started.  Note that the use of such a tag would also go a long way towards supporting the call for a "page-list" and hyperlinks as you've described them above.  If the publisher wanted to make use of such a tag, it would be available to them - otherwise the tag would be ignored by publisher and eReader software alike.



            • 3. Re: What is the best way to preserve page numbers from InDesign to EPUB?
              Douglas.Waterfall Adobe Employee

              With respect to the Reflowable export, I completely agree.


              Here is the thing that has held us back though (...we have lots to do anyway) - often the document has been extensively modified to prepare it for Reflowable EPUB export and so the page numbers have drifted from the original print version. So at export time the page boundaries (which of course we know) are not the original boundaries - it is the changed ones.


              Most of the interest around the page indexes is for the page-list where the Reflowable version is trying to associate a particular place with the original print version.


              We have considered offering some mechanism of inserting magic text anchors into the document BEFORE it is modified by the user for Reflowable EPUB. At export we would offer some control that would say "make me a page-list from these magic anchors I've already inserted" and we would be off to the races. But it has not yet seemed important enough yet and lots of other simpler issues need to be addressed.


              That's how I see it. Happy to hear more from your perspective.



              • 4. Re: What is the best way to preserve page numbers from InDesign to EPUB?
                evansreb Level 1

                I work at an academic publisher and all our books must retain page number references from the print version. Our ePubs are created from InDesign files (or pdfs) by CodeMantra.


                The page numbers appear in the html as:


                <p class="indent"><a id="page_18"></a>Because the method adopted in this study . . .


                and there is a file in the ePub's ops folder called page-map.xml that contains lines such as:


                <page name="17" href="xhtml/07_chapter.html#page_17"/>
                <page name="18" href="xhtml/07_chapter.html#page_18"/>
                <page name="19" href="xhtml/07_chapter.html#page_19"/>

                Page-map is, I believe, an Adobe function. It causes a validation error that can be ignored.

                There is a way to put these page numbers in the InDesign file by hand as anchored text frames but it is really labor intensive. Our service bureau, no doubt, uses a script that takes just a few moments. I know that Tseng Information Systems, a fabulous book composition house in Durham, NC, USA, has scripted this capability.

                Be aware that most eReaders won’t display these page numbers. Adobe Digital Editions is the only Mac progam I’ve seen that does display them, Calibre and (Mac) iBooks don't.

                Rebecca Evans

                UNC Press