Reference EPUB reading app: Readium

I recently just chanced upon a new EPUB reading app: Readium. This is a project by the IDPF, meant to be an open-source reference system and rendering engine for EPUB files. At the time of writing, there is an OSX binary and a Chrome extension for Readium. I will be examining the Chrome extension’s rendering capabilities below.

Prior to this, I had been using Calibre as my reference EPUB rendering app for its extensive list of supported EPUB features. As we shall see, Readium largely supports the same featureset, in addition to new features introduced in EPUB3, which I have not had the chance to test yet.

As with my previous post, I use Fate/Zero Volume 1 as the test EPUB file.

Interface #

Readium library view
Library interface

The Readium library interface shows a simple list of imported EPUB books; nothing fancy.

Readium reading view
Readium reading and navigation

In reading view, there’s a contents listing in the left sidebar, which can be hidden. Clicking the green arrow in the upper right hides the overlay interface, leaving only reading view.

In the images below, bringing the mouse cursor over the images shows them with the overlay view; moving the mouse cursor away returns the images to reading view. The overlay images may take some time to load.

Contents page #

F/Z Vol 1 Contents page
Readium – Contents page

The contents page rendering is pretty much identical to Calibre’s rendering, apart from anti-aliasing. @font-face is clearly supported here.

Chapter cover images #

F/Z Vol 1 Act 1 Cover
Readium – Act 1

The Act 1 cover image is stretched to full height, and centre-aligned. Compare this with other EPUB readers on the iPad3.

Chapter openings #

F/Z Vol 1 Act 1 opening
Readium – Act 1 opening

Again, pretty much the same rendering as Calibre. p:first-child selectors are working fine, as are (fake) small caps.

Body text #

F/Z Vol 1 - Act 1 body text
Readium – body text

Things that work: CSS float
Things that don’t work: CSS hyphenation

Again, pretty much the same as Calibre’s rendering.

Caveats #

Readium is still very much in beta, and some EPUB files, particularly non-EPUB-compliant files, will not open on it.

Despite this, I am ready to dump calibre and its various dependencies for this, since I do not use ebooks and other ebook formats extensively, and do not need most features of calibre apart from the ebook viewer.