Table of Contents
This charter proposal was submitted for a IDPF member consent vote on November 5 2012.
In March 2012, IDPF published the first version of EPUB 3 Fixed-Layout Documents, which defines a set of basic metadata properties for fixed-layout publications.
A set of more advanced layout-related features that were intended to be included in the above document were deferred from the first version (e.g. rendition selection via Media Queries). In addition, during deployment of the Fixed-Layout Documents specification, additional more advanced requirements and use cases that pertain to both fixed-layout documents, reflowable documents, and hybrids between the two, have been identified by various stakeholders in the community.
As described below in this charter proposal, the Advanced/Hybrid Layouts working group intends to publish a set of modular specifications that extends EPUB3 functionality to better meet the full needs of the ecosystem with regards to user and context adaptation and reading of image-based publications such as comics and magazines (see use cases below).
Note: in the context of this document, the term "image-based publication" is used to refer to any EPUB publication where the main publication content is represented using image data (e.g. using images referenced directly from the spine, images embedded in HTML or SVG, and/or vector graphics.
Note that in parallel to this project, extensions to the Fixed Layout Documents specification will be proposed that are intended to address initial viewing mode and mode transition properties, as well as allow the expression of author intent regarding display of margins and gaps between pages in synthetic spreads.
The defined mechanism shall integrate with EPUB 3 as follows:
Project participation is open to IDPF members and invited experts. (Note that invited expert status needs to be renewed for each IDPF project.)
The project charter spans one year in total. Once formed, the working group will decide on feature prioritization and versioning strategies, after which the milestones below can be dated.
Note that this working group will publish multiple specification documents, and in addition that some of the outcomes may be proposed for inclusion in the existing Fixed-Layout Documents specification as well as the main EPUB 3 specifications.
| Submission to Membership for 14 day comment period | October 5, 2012 |
| Submission to Membership for consent vote | November 5, 2012 |
| WG creation, formal project start | November 19, 2012 |
| WG Face-to-face 1 | TBD |
| First WG drafts | TBD |
| WG Face-to-face 2 | TBD |
| Second WG drafts | TBD |
| Proposed Specifications | TBD |
| Recommended Specifications | TBD (Target July 2013 for completion of all specification documents) |
| Maintenance/Tutorials | Through November 2013 |
Murata Makoto
Matthieu Kopp
Note: the use cases shown in this document are not meant to mandate behaviors of reading systems, but are intended to inform content design.
RS0 - In an EPUB publication that contains multiple renditions, there should be a way for publishers to specify the primary intended rendition.
RS1a Upon opening a multi-lingual EPUB publication, the Reading System automatically selects and presents the rendition that corresponds to the registered preferred language of the user.
RS1b As an alternative to RS1a, the user is able to override the automatic selection process and select a preferred rendition from a menu of available choices
RS1c While reading a multi-lingual EPUB publication, the user is able to switch between the available languages without losing the current reading position
RS1d In the case of image-based EPUB publications, the author and/or publisher is able to specify object areas (e.g. a balloon in the frame of comic) of a full-page and/or spread-page and display image and/or text, corresponding to the preferred language, over said object, to make it a multi-lingual EPUB. (See RS3 below for related use cases.)
RS1e Authors prepare different text for different levels of literacy of the same language, and the user (or the RS automatically) selects the text most appropriate for the user. A typical example of such levels is the number of understandable kanji characters by Japanese users.
RS2a When opening a multi-writing-mode EPUB publication for reading, the user is presented with a menu of the available writing modes, and is able to select the preferred mode
RS2b While reading a multi-writing-mode EPUB publication, the user is able to switch between the available modes without loosing the current reading position
RS3a While reading an image-based publication, a user is informed of the availability of and able to activate and access (aka "switch reading mode") text-based equivalents of identified areas (entire pages, sub-page regions) of the publication without losing the current reading position.
RS3b Upon opening an EPUB publication that contains both image- and text-based renditions, the Reading System automatically selects and presents the rendition that corresponds to the registered preferences of the user.
RS3c As an alternative to RS3b, the user is able to override the automatic selection process and select a preferred rendition from a menu of available choices
RS4a Upon opening an EPUB publication that contains multiple renditions adapted for different device characteristics (screen size, resolution, orientation, e-ink, etc), the most appropriate rendition is selected automatically and displayed to the user
RS4b On explicit request, the user is able to override the automatic selection described in RS4a and select a preferred rendition from a menu of available choices
RS4c When the device characteristics change dynamically (e.g. orientation change by the user), it is possible for a Reading System to change rendering to use a rendition that better fits the new circumstances, without losing the current reading position
RS5a In a rendition that contains the full ("purchased") publication contents, it is possible for publishers to specify a range of the publication as a "preview range" in order to enable users to evaluate the publication contents prior to completing a purchase
RS5b As alternative to RS5a, publishers are able to include a dedicated preview rendition in an EPUB publication (that may or may not contain the full ("purchased") rendition as well).
RS5c While reading a dedicated preview rendition (see RS5b), the user is able to switch to the full (purchased) rendition without losing the current reading position
Note: the use cases listed in RS5 are not guaranteed to remain useable when applied in combination with DRM schemes. The working group is not chartered to address such incompatibilities; the scope is to define preview modes prior to encryption, and for unencrypted content.
RS6a A user makes an annotation associated with a range in one text-based rendition in a multi-rendition EPUB publication, and is later able to access that same annotation in another rendition within the same publication.
RS6b A user makes an annotation associated with a region of one image-based rendition in a multi-rendition EPUB publication, and is later able to access that same annotation in another rendition within the same publication.
RS7a If a RS is not capable of opening a rendition for some reason, the RS may ignore it, except for the default rendition as defined in OCF 3.0. The default rendition is expected to be opened in any Reading systems including EPUB2 Reading systems.
SN1a In an image-based publication and as an alternative to full-page or spread-page view, the user is able to zoom the view to display only logical/pre-identified sub-regions of the page or spread.
SN1b In an image-based publication and full-page view, the user is able to zoom the full-page view and move manually through the page, thus overriding the intended order of the logical/pre-identified sub-regions described in SN1a. The user is subsequently able to resume navigation via the pre-identified reading order, from the current viewing position on the page.
SN2a (e.g., cell navigation in the zoom view)
In the zoom view described in SN1a and SN1c, a user is able to navigate forwards and backwards through the primary sub-regions (e.g: frames of comic) by a simple operation, following the sequences that are designed by the author and/or publisher, and without having to manually identify the next primary sub-region.
SN2b To allow for adaptation to users and context, publishers are able to provide multiple navigation sequences as described in SN2a.
SN2c An alternate navigation sequence, as described in SN2b, could be the same sequence of subregions where the subregions are optimized to look best for particular aspect ratios of various devices.
SN2d (e.g., cell navigation in the page or spread view)
In full-page view as well as spread-page view, the user is able to forward to the sub-regions which are navigated by an indicator which highlights the next sub-region to be read, following the sequence which is designed by the author and/or publisher.
SN3a Publishers are able to provide a navigation sequence consisting of a series of primary sub-regions that can each define secondary regions. Secondary regions are ordered along a secondary reading sequence within the primary region.
SN3b Using a simple action, a user is able to move between views of the page or spread computed from the primary and secondary regions. The progression through the navigation sequence consists in showing the primary and secondary regions using the following sequence: it starts at the primary sub-region, goes through the secondary sequence of the sub-region (when available) and then continues to the next primary sub-regions.
SN3c Publishers are able to specify whether a specific primary region should always been seen in full before zooming to the secondary regions.
SN3d A user is able to specify his level of legibility by zooming the page view; the secondary navigation sequences are adapted to preserve the user's choice of zoom while respecting the publisher's intention.
SN3eUsing a simple action, a user is able to select a specific sub-region. This will focus on the primary or secondary sub-region by automatically zooming the page to the last value of the zoom that was specified by the user.
SN3f While focused on a sub-region, a simple action should move backward to the beginning of the reading sequence to which this sub-region belongs.
RC1a For informative and/or artistic effect, the publisher can include declarations of transition effects (visual, auditorial, haptic, etc) that could occur on sub-region and page navigation events. (Note: see Out of Scope section above)
RC1b In an image-based publication and spread-page view, the user is able to zoom the spread-page view and move through the page.
RC1c The RS should optimize the viewed area of the page by going through the secondary sequences and displaying the greatest number of secondary sub-regions while maintaining the user defined zoom factor. Computing the next view should consist in repeating this step until all secondary sub-regions have been displayed. When no more secondary sub-region is available, the RS should focus on the next primary region and apply the same step again.
RC1d The RS can decide to merge primary regions if the screen size is such that it allows to view in full more than 1 primary region while maintaining the zoom factor chosen by the user. If a publisher has explicitly defined that a primary subregion should be shown in full.