Now that EPUB 3 is an IDPF Proposed Specification it seems like a good time to update some of our EPUB blog posts. One of the most popular was Best practices in ePub cover images, which helped clarify how to include a cover image for most ebook readers. While cover image markup wasn’t specified in EPUB, I’m happy to report that EPUB 3 clearly explains how to include a dedicated cover image.
Note: If you’re new to the EPUB 3 specifications, the best place to get a clear introduction to the four parts of the specification is the EPUB 3 Overview. Marking a specific image is a metadata problem at the publication level, so we’ll be referring to the EPUB Publications 3.0 specification. As expected, it includes “Publication metadata — mechanisms for including and/or referencing metadata applicable to the entire Publication and particular resources within it.”
Without further delay, here is the markup to mark an image as the cover in EPUB 3:
properties attribute is added to an otherwise “normal” OPF
item and is all that’s required to mark an image as the cover. While including a cover image is still optional in EPUB 3, you may only mark one image as the cover.
Most of the metadata improvements in EPUB 3 are based on this
If there are specific EPUB 3 topics you’d like to see us write about, please leave a note in the comments—Thanks!