Bring documents to mobile devices the new epub output for ebooks

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Opal Kelley
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4 Popular e-book formats In order of popularity PDF (normal, scanned) epub KF8 / PRC (Amazon Kindle) DJVU (scans with high compression) Usability on mobile devices? Nuance Communications, Inc. All rights reserved. Page 4

15 epub 3.0 This is the latest standard version for epubs Supported by ios Almost every epub reader can display it PC, Mac, Android Necessary for fancy floating footnotes (see later) Amazon s Kindle readers can consume it after conversion (send epub as to the device) Nuance Communications, Inc. All rights reserved. Page 15

16 Technology challenges The basis for creating good quality flowing representation of documents is to determine well its logical units and their properties, like paragraphs (even if they cross pages) columns tables graphics (non-textual areas) headers, footers, page numbering headings (also needed for table-of-contents generation) footnotes Nuance Communications, Inc. All rights reserved. Page 16

17 Workflow for epub creation Setting the new Book mode Finding headers and footers Finding footnotes and their references Finding the headings and their level Generating table-of-contents from the headings Using the new epub output converter Nuance Communications, Inc. All rights reserved. Page 17

18 Book mode A new approach to determine the logical units of the document Switches to flowing mode as opposed to page layout fidelity The latter is the usual default for text outputs Paragraph line spaces gets normalized rather than being precisely defined Single, 1.5x, double Finds paragraphs crossing pages and links the parts together Finds footnotes and their references Can be selected using a new setting ON: set "Kernel.Processing.Mode to PROCESSING_BOOK OFF: set "Kernel.Processing.Mode to PROCESSING_NORMAL Nuance Communications, Inc. All rights reserved. Page 18

19 epub-specific formatting Multi-columns cannot be used Tables can be utilized for placing objects side-by-side, like text and graphics Font size scaling is relative by default (no absolute point sizes) 100% is for detected sizes of 9-13 pts, others are expressed as 50%, 75%, 100%, 133%, 150%, 200%. This makes the output more uniform Uses special properties to control the formatting details CharFont, CharSize, CharStyle, ParAlignment, ParIndent, ParFirstIndent, ParLinespacing, ParSpacing, FootNotes, Cross-references, Bullets/Numbering, LineBreaks Nuance Communications, Inc. All rights reserved. Page 19

20 epub-specific formatting (continued) Do not assume specific dimensions for target device Using relative scaling where possible, like column widths, indents, picture sizes Dimensions are relative to each other or to the page size, e.g.: table columns are defined as percentages of full width Do not specify right margin in left aligned paragraphs or vice versa Do not specify horizontal or vertical cell alignment Nuance Communications, Inc. All rights reserved. Page 20

22 Table sample Converted using a common free PC application Text is laid out as individual paragraphs for each line of each cell, no table structure Nuance Communications, Inc. All rights reserved. Page 22

29 Dual table-of-contents (TOC) Existing table of contents cannot be used They are not links for scanned documents The page numbers do not apply in epub readers We need to create two TOCs epub2 and epub3 Necessary for older readers We analyze paragraph properties and assign heading levels (h1, h2) to them The heading levels control the generation of the table-ofcontents Nuance Communications, Inc. All rights reserved. Page 29

33 epub output converter file splitting epub files are zipped packages The actual text of the book is contained in several HTML files We impose a limit of 256kB Some readers have memory problems with larger files It speeds up the loading of the text If we detect chapter headings we try to break the text there But we don t go below 8kB (except for the end of document) Nuance Communications, Inc. All rights reserved. Page 33

34 Improvements to help document scanning Improved handling of facing pages ( open book ) Camera input Auto detection of the source Using EXIF information in JPEG files Can be overridden with a new camera flag setting Resolution estimation for optimal text size Resolution enhancement for small characters Subsampling for zoomed-in text Improved binarization method selected automatically Correction for uneven lighting Nuance Communications, Inc. All rights reserved. Page 34

39 epub Simple mode Recommended for lower quality scans or for documents with a very simple structure Does not try to preserve too much formatting, the output is even more portable between readers Its output format name is "Converters.Text.ePubSimple Internally defaults to the following Converters.Text.ePubSimple.CharFont = FALSE Converters.Text.ePubSimple.CharSize = FALSE Converters.Text.ePubSimple.CharStyle = FALSE Converters.Text.ePubSimple.ParAlignment = FALSE Converters.Text.ePubSimple.ParIndent = FALSE Converters.Text.ePubSimple.ParLinespacing = FALSE Converters.Text.ePubSimple.ParSpacing = FALSE Nuance Communications, Inc. All rights reserved. Page 39

40 epub Poem mode Recommended for poems where the line endings do have importance Its output format name is "Converters.Text.ePubPoem Internally defaults to the following Converters.Text.ePubPoem.LineBreaks = TRUE Nuance Communications, Inc. All rights reserved. Page 40

43 epub Regular mode For good quality input (like normal PDFs) this delivers the best fidelity Especially useful if the formatting is complex with varying font sizes, indentations etc. Its output format name is "Converters.Text.ePub Nuance Communications, Inc. All rights reserved. Page 43

Best practices for producing high quality PDF files

University of Michigan Deep Blue deepblue.lib.umich.edu 2006-05-05 Best practices for producing high quality PDF files Formats Group, Deep Blue http://hdl.handle.net/2027.42/58005 Best practices for producing